document_title: Fundamental interaction

question_text: the fundamental force that is currently the weakest of all is

text: Fundamental interaction

text: History[edit]

text: Classical theory[edit]

text: In his 1687 theory, Isaac Newton postulated space as an infinite and unalterable physical structure existing before, within, and around all objects while their states and relations unfold at a constant pace everywhere, thus absolute space and time. Inferring that all objects bearing mass approach at a constant rate, but collide by impact proportional to their masses, Newton inferred that matter exhibits an attractive force. His law of universal gravitation mathematically stated it to span the entire universe instantly (despite absolute time), or, if not actually a force, to be instant interaction among all objects (despite absolute space.) As conventionally interpreted, Newton's theory of motion modelled a central force without a communicating medium.[5] Thus Newton's theory violated the first principle of mechanical philosophy, as stated by Descartes, No action at a distance. Conversely, during the 1820s, when explaining magnetism, Michael Faraday inferred a field filling space and transmitting that force. Faraday conjectured that ultimately, all forces unified into one.

text: In the early 1870s, James Clerk Maxwell unified electricity and magnetism as effects of an electromagnetic field whose third consequence was light, travelling at constant speed in a vacuum. The electromagnetic field theory contradicted predictions of Newton's theory of motion, unless physical states of the luminiferous aether—presumed to fill all space whether within matter or in a vacuum and to manifest the electromagnetic field—aligned all phenomena and thereby held valid the Newtonian principle relativity or invariance.

text: The Standard Model[edit]

text: The Standard Model of particle physics was developed throughout the latter half of the 20th century. In the Standard Model, the electromagnetic, strong, and weak interactions associate with elementary particles, whose behaviours are modelled in quantum mechanics (QM). For predictive success with QM's probabilistic outcomes, particle physics conventionally models QM events across a field set to special relativity, altogether relativistic quantum field theory (QFT).[6] Force particles, called gauge bosons—force carriers or messenger particles of underlying fields—interact with matter particles, called fermions. Everyday matter is atoms, composed of three fermion types: up-quarks and down-quarks constituting, as well as electrons orbiting, the atom's nucleus. Atoms interact, form molecules, and manifest further properties through electromagnetic interactions among their electrons absorbing and emitting photons, the electromagnetic field's force carrier, which if unimpeded traverse potentially infinite distance. Electromagnetism's QFT is quantum electrodynamics (QED).

text: The electromagnetic interaction was modelled with the weak interaction, whose force carriers are W and Z bosons, traversing the minuscule distance, in electroweak theory (EWT). Electroweak interaction would operate at such high temperatures as soon after the presumed Big Bang, but, as the early universe cooled, split into electromagnetic and weak interactions. The strong interaction, whose force carrier is the gluon, traversing minuscule distance among quarks, is modeled in quantum chromodynamics (QCD). EWT, QCD, and the Higgs mechanism, whereby the Higgs field manifests Higgs bosons that interact with some quantum particles and thereby endow those particles with mass comprise particle physics' Standard Model (SM). Predictions are usually made using calculational approximation methods, although such perturbation theory is inadequate to model some experimental observations (for instance bound states and solitons.) Still, physicists widely accept the Standard Model as science's most experimentally confirmed theory.

text: Beyond the Standard Model, some theorists work to unite the electroweak and strong interactions within a Grand Unified Theory (GUT). Some attempts at GUTs hypothesize "shadow" particles, such that every known matter particle associates with an undiscovered force particle, and vice versa, altogether supersymmetry (SUSY). Other theorists seek to quantize the gravitational field by the modelling behaviour of its hypothetical force carrier, the graviton and achieve quantum gravity (QG). One approach to QG is loop quantum gravity (LQG). Still other theorists seek both QG and GUT within one framework, reducing all four fundamental interactions to a Theory of Everything (ToE). The most prevalent aim at a ToE is string theory, although to model matter particles, it added SUSY to force particles—and so, strictly speaking, became superstring theory. Multiple, seemingly disparate superstring theories were unified on a backbone, M-theory. Theories beyond the Standard Model remain highly speculative, lacking great experimental support.

text: Overview of the fundamental interactions[edit]

text: In the conceptual model of fundamental interactions, matter consists of fermions, which carry properties called charges and spin ±1⁄2 (intrinsic angular momentum ±ħ⁄2, where ħ is the reduced Planck constant). They attract or repel each other by exchanging bosons.

text: The interaction of any pair of fermions in perturbation theory can then be modelled thus:

text: The exchange of bosons always carries energy and momentum between the fermions, thereby changing their speed and direction. The exchange may also transport a charge between the fermions, changing the charges of the fermions in the process (e.g., turn them from one type of fermion to another). Since bosons carry one unit of angular momentum, the fermion's spin direction will flip from +1⁄2 to −1⁄2 (or vice versa) during such an exchange (in units of the reduced Planck's constant).

text: Because an interaction results in fermions attracting and repelling each other, an older term for "interaction" is force.

text: According to the present understanding, there are four fundamental interactions or forces: gravitation, electromagnetism, the weak interaction, and the strong interaction. Their magnitude and behaviour vary greatly, as described in the table below. Modern physics attempts to explain every observed physical phenomenon by these fundamental interactions. Moreover, reducing the number of different interaction types is seen as desirable. Two cases in point are the unification of:

text:
Electric and magnetic force into electromagnetism;
The electromagnetic interaction and the weak interaction into the electroweak interaction; see below.

text: Both magnitude ("relative strength") and "range", as given in the table, are meaningful only within a rather complex theoretical framework. It should also be noted that the table below lists properties of a conceptual scheme that is still the subject of ongoing research.

text:
Interaction
Current theory
Mediators
Relative strength[7]
Long-distance behavior
Range (m)[citation needed]

Strong
Quantum chromodynamics
(QCD)
gluons
1038

∼
r

{\displaystyle {\sim r}}

(Color confinement, see discussion below)
10−15

Electromagnetic
Quantum electrodynamics
(QED)
photons
1036

1

r

2

{\displaystyle {\frac {1}{r^{2}}}}

∞

Weak
Electroweak Theory (EWT)
W and Z bosons
1025

1
r

e

−

m

W
,
Z

r

{\displaystyle {\frac {1}{r}}\ e^{-m_{W,Z}\ r}}

10−18

Gravitation
General relativity
(GR)
gravitons (hypothetical)
1

1

r

2

{\displaystyle {\frac {1}{r^{2}}}}

∞

text: The modern (perturbative) quantum mechanical view of the fundamental forces other than gravity is that particles of matter (fermions) do not directly interact with each other, but rather carry a charge, and exchange virtual particles (gauge bosons), which are the interaction carriers or force mediators. For example, photons mediate the interaction of electric charges, and gluons mediate the interaction of color charges.

text: The interactions[edit]

text: Gravity[edit]

text: Gravitation is by far the weakest of the four interactions at the atomic scale, where electromagnetic interactions dominate. But the idea that the weakness of gravity can easily be demonstrated by suspending a pin using a simple magnet (such as a refrigerator magnet) is fundamentally flawed. The only reason the magnet is able to hold the pin against the gravitational pull of the entire Earth is due to its relative proximity. There is clearly a short distance of separation between magnet and pin where a breaking point is reached, and due to the large mass of Earth this distance is disappointingly small.

text: Thus gravitation is very important for macroscopic objects and over macroscopic distances for the following reasons. Gravitation:

text:
Is the only interaction that acts on all particles having mass, energy and/or momentum
Has an infinite range, like electromagnetism but unlike strong and weak interaction[citation needed]
Cannot be absorbed, transformed, or shielded against
Always attracts and never repels (see function of geodesic equation in general relativity)

text: Even though electromagnetism is far stronger than gravitation, electrostatic attraction is not relevant for large celestial bodies, such as planets, stars, and galaxies, simply because such bodies contain equal numbers of protons and electrons and so have a net electric charge of zero. Nothing "cancels" gravity, since it is only attractive, unlike electric forces which can be attractive or repulsive. On the other hand, all objects having mass are subject to the gravitational force, which only attracts. Therefore, only gravitation matters on the large-scale structure of the universe.

text: The long range of gravitation makes it responsible for such large-scale phenomena as the structure of galaxies and black holes and it retards the expansion of the universe.[citation needed] Gravitation also explains astronomical phenomena on more modest scales, such as planetary orbits, as well as everyday experience: objects fall; heavy objects act as if they were glued to the ground, and animals can only jump so high.

text: Gravitation was the first interaction to be described mathematically. In ancient times, Aristotle hypothesized that objects of different masses fall at different rates. During the Scientific Revolution, Galileo Galilei experimentally determined that this was not the case — neglecting the friction due to air resistance, and buoyancy forces if an atmosphere is present (e.g. the case of a dropped air-filled balloon vs a water-filled balloon) all objects accelerate toward the Earth at the same rate. Isaac Newton's law of Universal Gravitation (1687) was a good approximation of the behaviour of gravitation. Our present-day understanding of gravitation stems from Albert Einstein's General Theory of Relativity of 1915, a more accurate (especially for cosmological masses and distances) description of gravitation in terms of the geometry of spacetime.

text: Merging general relativity and quantum mechanics (or quantum field theory) into a more general theory of quantum gravity is an area of active research. It is hypothesized that gravitation is mediated by a massless spin-2 particle called the graviton.

text: Although general relativity has been experimentally confirmed (at least for weak fields[which?]) on all but the smallest scales, there are rival theories of gravitation. Those taken seriously by[citation needed] the physics community all reduce to general relativity in some limit, and the focus of observational work is to establish limitations on what deviations from general relativity are possible.

text: Proposed extra dimensions could explain why the gravity force is so weak.[8]

text: Electroweak interaction[edit]

text: Electromagnetism and weak interaction appear to be very different at everyday low energies. They can be modelled using two different theories. However, above unification energy, on the order of 100 GeV, they would merge into a single electroweak force.

text: Electroweak theory is very important for modern cosmology, particularly on how the universe evolved. This is because shortly after the Big Bang, the temperature was approximately above 1015 K. Electromagnetic force and weak force were merged into a combined electroweak force.

text: For contributions to the unification of the weak and electromagnetic interaction between elementary particles, Abdus Salam, Sheldon Glashow and Steven Weinberg were awarded the Nobel Prize in Physics in 1979.[9][10]

text: Electromagnetism[edit]

text: Electromagnetism is the force that acts between electrically charged particles. This phenomenon includes the electrostatic force acting between charged particles at rest, and the combined effect of electric and magnetic forces acting between charged particles moving relative to each other.

text: Electromagnetism is infinite-ranged like gravity, but vastly stronger, and therefore describes a number of macroscopic phenomena of everyday experience such as friction, rainbows, lightning, and all human-made devices using electric current, such as television, lasers, and computers. Electromagnetism fundamentally determines all macroscopic, and many atomic levels, properties of the chemical elements, including all chemical bonding.

text: In a four kilogram (~1 gallon) jug of water there are

text: of total electron charge. Thus, if we place two such jugs a meter apart, the electrons in one of the jugs repel those in the other jug with a force of

text: This is larger than the planet Earth would weigh if weighed on another Earth. The atomic nuclei in one jug also repel those in the other with the same force. However, these repulsive forces are canceled by the attraction of the electrons in jug A with the nuclei in jug B and the attraction of the nuclei in jug A with the electrons in jug B, resulting in no net force. Electromagnetic forces are tremendously stronger than gravity but cancel out so that for large bodies gravity dominates.

text: Electrical and magnetic phenomena have been observed since ancient times, but it was only in the 19th century that it was discovered that electricity and magnetism are two aspects of the same fundamental interaction. By 1864, Maxwell's equations had rigorously quantified this unified interaction. Maxwell's theory, restated using vector calculus, is the classical theory of electromagnetism, suitable for most technological purposes.

text: The constant speed of light in a vacuum (customarily described with the letter "c") can be derived from Maxwell's equations, which are consistent with the theory of special relativity. Einstein's 1905 theory of special relativity, however, which flows from the observation that the speed of light is constant no matter how fast the observer is moving, showed that the theoretical result implied by Maxwell's equations has profound implications far beyond electromagnetism on the very nature of time and space.

text: In another work that departed from classical electro-magnetism, Einstein also explained the photoelectric effect by hypothesizing that light was transmitted in quanta, which we now call photons. Starting around 1927, Paul Dirac combined quantum mechanics with the relativistic theory of electromagnetism. Further work in the 1940s, by Richard Feynman, Freeman Dyson, Julian Schwinger, and Sin-Itiro Tomonaga, completed this theory, which is now called quantum electrodynamics, the revised theory of electromagnetism. Quantum electrodynamics and quantum mechanics provide a theoretical basis for electromagnetic behavior such as quantum tunneling, in which a certain percentage of electrically charged particles move in ways that would be impossible under the classical electromagnetic theory, that is necessary for everyday electronic devices such as transistors to function.

text: Weak interaction[edit]

text: The weak interaction or weak nuclear force is responsible for some nuclear phenomena such as beta decay. Electromagnetism and the weak force are now understood to be two aspects of a unified electroweak interaction — this discovery was the first step toward the unified theory known as the Standard Model. In the theory of the electroweak interaction, the carriers of the weak force are the massive gauge bosons called the W and Z bosons. The weak interaction is the only known interaction which does not conserve parity; it is left-right asymmetric. The weak interaction even violates CP symmetry but does conserve CPT.

text: Strong interaction[edit]

text: The strong interaction, or strong nuclear force, is the most complicated interaction, mainly because of the way it varies with distance. At distances greater than 10 femtometers, the strong force is practically unobservable. Moreover, it holds only inside the atomic nucleus.

text: After the nucleus was discovered in 1908, it was clear that a new force, today known as the nuclear force, was needed to overcome the electrostatic repulsion, a manifestation of electromagnetism, of the positively charged protons. Otherwise, the nucleus could not exist. Moreover, the force had to be strong enough to squeeze the protons into a volume that is about 10−15 m, much smaller than that of the entire atom. From the short range of this force, Hideki Yukawa predicted that it was associated with a massive particle, whose mass is approximately 100 MeV.

text: The 1947 discovery of the pion ushered in the modern era of particle physics. Hundreds of hadrons were discovered from the 1940s to 1960s, and an extremely complicated theory of hadrons as strongly interacting particles was developed. Most notably:

text:
The pions were understood to be oscillations of vacuum condensates;
Jun John Sakurai proposed the rho and omega vector bosons to be force carrying particles for approximate symmetries of isospin and hypercharge;
Geoffrey Chew, Edward K. Burdett and Steven Frautschi grouped the heavier hadrons into families that could be understood as vibrational and rotational excitations of strings.

text: While each of these approaches offered deep insights, no approach led directly to a fundamental theory.

text: Murray Gell-Mann along with George Zweig first proposed fractionally charged quarks in 1961. Throughout the 1960s, different authors considered theories similar to the modern fundamental theory of quantum chromodynamics (QCD) as simple models for the interactions of quarks. The first to hypothesize the gluons of QCD were Moo-Young Han and Yoichiro Nambu, who introduced the quark color charge and hypothesized that it might be associated with a force-carrying field. At that time, however, it was difficult to see how such a model could permanently confine quarks. Han and Nambu also assigned each quark color an integer electrical charge, so that the quarks were fractionally charged only on average, and they did not expect the quarks in their model to be permanently confined.

text: In 1971, Murray Gell-Mann and Harald Fritzsch proposed that the Han/Nambu color gauge field was the correct theory of the short-distance interactions of fractionally charged quarks. A little later, David Gross, Frank Wilczek, and David Politzer discovered that this theory had the property of asymptotic freedom, allowing them to make contact with experimental evidence. They concluded that QCD was the complete theory of the strong interactions, correct at all distance scales. The discovery of asymptotic freedom led most physicists to accept QCD since it became clear that even the long-distance properties of the strong interactions could be consistent with experiment if the quarks are permanently confined.

text: Assuming that quarks are confined, Mikhail Shifman, Arkady Vainshtein and Valentine Zakharov were able to compute the properties of many low-lying hadrons directly from QCD, with only a few extra parameters to describe the vacuum. In 1980, Kenneth G. Wilson published computer calculations based on the first principles of QCD, establishing, to a level of confidence tantamount to certainty, that QCD will confine quarks. Since then, QCD has been the established theory of the strong interactions.

text: QCD is a theory of fractionally charged quarks interacting by means of 8 bosonic particles called gluons. The gluons interact with each other, not just with the quarks, and at long distances the lines of force collimate into strings. In this way, the mathematical theory of QCD not only explains how quarks interact over short distances but also the string-like behavior, discovered by Chew and Frautschi, which they manifest over longer distances.

text: Beyond the Standard Model[edit]

text: Numerous theoretical efforts have been made to systematize the existing four fundamental interactions on the model of electroweak unification.

text: Grand Unified Theories (GUTs) are proposals to show that the three fundamental interactions described by the Standard Model are all different manifestations of a single interaction with symmetries that break down and create separate interactions below some extremely high level of energy. GUTs are also expected to predict some of the relationships between constants of nature that the Standard Model treats as unrelated, as well as predicting gauge coupling unification for the relative strengths of the electromagnetic, weak, and strong forces (this was, for example, verified at the Large Electron–Positron Collider in 1991 for supersymmetric theories).

text: Theories of everything, which integrate GUTs with a quantum gravity theory face a greater barrier, because no quantum gravity theories, which include string theory, loop quantum gravity, and twistor theory, have secured wide acceptance. Some theories look for a graviton to complete the Standard Model list of force-carrying particles, while others, like loop quantum gravity, emphasize the possibility that time-space itself may have a quantum aspect to it.

text: Some theories beyond the Standard Model include a hypothetical fifth force, and the search for such a force is an ongoing line of experimental research in physics. In supersymmetric theories, there are particles that acquire their masses only through supersymmetry breaking effects and these particles, known as moduli can mediate new forces. Another reason to look for new forces is the recent discovery that the expansion of the universe is accelerating (also known as dark energy), giving rise to a need to explain a nonzero cosmological constant, and possibly to other modifications of general relativity. Fifth forces have also been suggested to explain phenomena such as CP violations, dark matter, and dark flow.

text: In December 2015, two observations in the ATLAS and CMS detectors at the Large Hadron Collider hinted at the existence of a new particle six times heavier than the Higgs Boson.[11] However, after obtaining more experimental data, the anomaly appeared to not be significant.[12]


document_title: Palace of Versailles

question_text: what is the significance of the seven rooms in the palace

root

text: Palace of Versailles

text: History[edit]

text: Architectural history[edit]

text: 17th century[edit]

text: First built by Louis XIII in 1624, as a hunting lodge of brick and stone, and the architect was Jacques Lemercier, the edifice was enlarged into a royal palace by Louis XIV.[2] The first phase of the expansion (c. 1661–1678) was designed and supervised by the architect Louis Le Vau. It culminated in the addition of three new wings of stone (the enveloppe), which encompassed Louis XIII's original building on the north, south, and west (the garden side). After Le Vau's death in 1670, the work was taken over and completed by his assistant François d'Orbay.[3] Charles Le Brun designed and supervised the elaborate interior decoration, and André Le Nôtre landscaped the extensive Gardens of Versailles. Le Brun and Le Nôtre collaborated on the numerous fountains, and Le Brun supervised the design and installation of countless statues.[4]

tag: p

text: During the second phase of expansion of the mansion (c. 1678–1715), two enormous wings north and south of the wings flanking the Cour Royale (Royal Courtyard) were added by the architect Jules Hardouin-Mansart. He also replaced Le Vau's large terrace, facing the garden on the west, with what became the most famous room of the palace, the Hall of Mirrors. Mansart also built the Petites Écuries and Grandes Écuries (stables) across the Place d'Armes, on the eastern side of the château, and, in 1687, the Grand Trianon, or Trianon de Marbre (Marble Trianon), replacing Le Vau's 1668 Trianon de Porcelaine in the northern section of the park. Work was sufficiently advanced by 1682, that Louis XIV was able to proclaim Versailles his principal residence and the seat of the government of the Kingdom of France and also to give rooms in the palace to almost all of his courtiers. After the death of his consort Maria Theresa of Spain in 1683, Louis XIV undertook the enlargement and remodeling of the royal apartments in the original part of the palace, the former hunting lodge built by his father. The Royal Chapel of Versailles, located at the south end of the north wing, was begun by Mansart in 1688, and after his death in 1708 completed by his assistant Robert de Cotte in 1710.[5]

text: Cost[edit]

text: One of the most baffling aspects to the study of Versailles is the cost – how much Louis XIV and his successors spent on Versailles. Owing to the nature of the construction of Versailles and the evolution of the role of the palace, construction costs were essentially a private matter. Initially, Versailles was planned to be an occasional residence for Louis XIV and was referred to as the "king's house".[6] Accordingly, much of the early funding for construction came from the king's own purse, funded by revenues received from his appanage as well as revenues from the province of New France (Canada), which, while part of France, was a private possession of the king and therefore exempt from the control of the Parliaments.[7]

text: Once Louis XIV embarked on his building campaigns, expenses for Versailles became more of a matter for public record, especially after Jean-Baptiste Colbert assumed the post of finance minister. Expenditures on Versailles have been recorded in the compendium known as the Comptes des bâtiments du roi sous le règne de Louis XIV and which was edited and published in five volumes by Jules Guiffrey in the 19th century. These volumes provide valuable archival material pursuant to the financial expenditures of all aspects of Versailles from the payments disbursed for many trades as varied as artists and mole catchers.[8]

text: To counter the costs of Versailles during the early years of Louis XIV's personal reign, Colbert decided that Versailles should be the "showcase" of France.[9] Accordingly, all materials that went into the construction and decoration of Versailles were manufactured in France. Even the mirrors used in the decoration of the Hall of Mirrors were made in France. While Venice in the 17th century had the monopoly on the manufacture of mirrors, Colbert succeeded in enticing a number of artisans from Venice to make the mirrors for Versailles. However, owing to Venetian proprietary claims on the technology of mirror manufacture, the Venetian government ordered the assassination of the artisans to keep the secrets proprietary to the Venetian Republic.[9] To meet the demands for decorating and furnishing Versailles, Colbert nationalised the tapestry factory owned by the Gobelin family, to become the Manufacture royale des Gobelins.[9]

text: In 1667, the name of the enterprise was changed to the Manufacture royale des Meubles de la Couronne. The Gobelins were charged with all decoration needs of the palace, which was under the direction of Charles Le Brun.[9]

text: One of the most costly elements in the furnishing of the grands appartements during the early years of the personal reign of Louis XIV was the silver furniture, which can be taken as a standard – with other criteria – for determining a plausible cost for Versailles. The Comptes meticulously list the expenditures on the silver furniture – disbursements to artists, final payments, delivery – as well as descriptions and weight of items purchased. Entries for 1681 and 1682 concerning the silver balustrade used in the salon de Mercure serve as an example:

text: Year 1681

tag: ul

text: II. 5 In anticipation: For the silver balustrade for the king's bedroom: 90,000 livres

text:
II. 7 18 November to Sieur du Metz, 43,475 livres 5 sols for delivery to Sr. Lois and to Sr. de Villers for payment of 142,196 livres for the silver balustrade that they are making for the king's bedroom and 404 livres for tax: 48,861 livres 5 sol.
II. 15 16 June 1681 – 23 January 1682 to Sr. Lois and Sr. de Villers silversmiths on account for the silver balustrade that they are making for the king's use (four payments): 88,457 livres 5 sols.
II. 111 25 March – 18 April to Sr. Lois and Sr. de Villers silversmiths who are working on a silver balustrade for the king, for continued work (two payments): 40,000 livres

text: Year 1682

text: II. 129 21 March to Sr. Jehannot de Bartillay 4,970 livres 12 sols for the delivery to Sr. Lois and de Villers silversmiths for, with 136,457 livres 5 sol to one and 25,739 livres 10 sols to another, making the 38 balusters, 17 pilasters, the base and the cornice for the balustrade for the château of Versailles weighing 4,076 marc at the rate of 41 livres the marc[a] including 41 livres 2 sols for tax: 4,970 livres 12 sols.[8]

text: Accordingly, the silver balustrade, which contained in excess of one ton of silver, cost in excess of 560,000 livres. It is difficult – if not impossible – to give an accurate rate of exchange between 1682 and today.[b] However, Frances Buckland provides valuable information that provides an idea of the true cost of the expenditures at Versailles during the time of Louis XIV. In 1679, Mme de Maintenon stated that the cost of providing light and food for twelve people for one day amounted to slightly more than 14 livres.[10] In December 1689, to defray the cost of the War of the League of Augsburg, Louis XIV ordered all the silver furniture and articles of silver at Versailles – including chamber pots – sent to the mint to be melted.[11]

text: Clearly, the silver furniture alone represented a significant outlay in the finances of Versailles. While the decoration of the palace was costly, certain other costs were minimised. For example, labour for construction was often low, due largely to the fact that the army during times of peace and during the winter, when wars were not waged, was pressed into action at Versailles. Additionally, given the quality and uniqueness of the items produced at the Gobelins for use and display at Versailles, the palace served as a venue to showcase not only the success of Colbert's mercantilism, but also to display the finest that France could produce.[12]

text: Estimates of the amount spent to build Versailles are speculative. An estimate in 2000 placed the amount spent during the Ancien Régime as US$2 billion,[13] this figure being, in all probability, an under-evaluation. France's Fifth Republic expenditures alone, directed to restoration and maintenance at Versailles, undoubtedly surpass those of the Sun King.

text: 18th century[edit]

text: In 1738, Louis XV remodeled the king's petit appartement on the north side of the Cour de Marbre, originally the entrance court of the old château, and built a pavilion not far from the Grand Trianon, the Petit Trianon, designed by Ange-Jacques Gabriel and completed in 1768. At the north end of the north wing, Gabriel also built a theatre, the Opéra, completed in 1770, in time for the marriage of Louis-Auguste Dauphin of France to the Austrian Archduchess Marie Antoinette. After his accession to the throne, Louis XVI made few changes to the palace, primarily to the royal private apartments.[14] However, after Louis XVI gave Marie Antoinette the Petit Trianon in 1774, the queen made extensive changes to the interior, added a theater, the Théâtre de la Reine. She also totally transformed the arboretum planted during the reign of Louis XV into what became known as the Hameau de la Reine.[15] (The trees removed from the Trianon arboretum were brought & replanted in the Jardin des Plantes in Paris.)

text: 19th century[edit]

text: During the French Revolution, after the royal family's forced move to Paris on 6 October 1789, three years before the fall of the monarchy, Versailles fell into disrepair and most of the furniture was sold. Some restoration work was undertaken by Napoleon in 1810 and Louis XVIII in 1820, but the principal effort to restore and maintain Versailles was initiated by Louis-Philippe, when he created the Musée de l'Histoire de France, dedicated to "all the glories of France". The museum is located in the Aile du Midi (South Wing), which during the Ancien Régime had been used to lodge the members of the royal family. It was begun in 1833 and inaugurated on 30 June 1837. Its most famous room is the Galerie des Batailles (Hall of Battles), which lies on most of the length of the second floor.[14]

text: 20th century[edit]

text: Neglect after October 1789, when the royal family had to leave Versailles, and the ravages of war in parts of the 19th and 20th centuries have left their mark on the palace and its park. Post-World War II governments have sought to repair these damages. On the whole, they have been successful, but some of the more costly items, such as the vast array of fountains, have yet to be put back completely in service. As spectacular as they might seem now, they were even more extensive in the 18th century. The 18th-century waterworks at Marly— the Machine de Marly that fed the fountains— was possibly the biggest mechanical system of its time. The water came in from afar on monumental stone aqueducts which have long ago fallen into disrepair or been torn down. Some aqueducts, such as the unfinished Canal de l'Eure, which passes through the gardens of the château de Maintenon, were never completed for want of resources or due to the exigencies of war. The search for sufficient supplies of water was never fully realised even during the apogee of the reign of the Sun King, as the fountains could not be operated together satisfactorily for any significant periods of time.[16]

text: The restoration initiatives launched by the Fifth Republic have proven to be perhaps more costly than the expenditures of the palace in the Ancien Régime. Starting in the 1950s, when the museum of Versailles was under the directorship of Gérald van der Kemp, the objective was to restore the palace to its state – or as close to it as possible – in 1789 when the royal family left the palace. Among the early projects was the repair of the roof over the Hall of Mirrors; the publicity campaign brought international attention to the plight of post-war Versailles and garnered much foreign money including a grant from the Rockefeller Foundation. Concurrently, in the Soviet Union (Russia since 26 December 1991), the restoration of the Pavlovsk Palace located 25 kilometers from the center of Leningrad – today's Saint Petersburg – brought the attention of French Ministry of Culture, including that of the curator of Versailles.[17]

text: Pavlovsk Palace was built by Catherine the Great's son Paul. The czarevitch and his wife, Marie Feodorovna, were ardent francophiles, who, on a visit to France and Versailles in May and June 1782, purchased great quantities of silk, which they later used to upholster furniture in Pavlovsk. The palace survived the Russian Revolution intact – descendants of Paul I were living in the palace at the time the communists evicted them – however, during the Second World War, the furniture and artifacts housed in the palace, which had been transformed into a museum, were removed. In the process of evacuation the museum collections, remnants of the silks purchased by Paul I of Russia and Marie Feodorovna were found and preserved. After the war when Soviet authorities were restoring the palace, which had been gutted by the retreating Nazi forces, they recreated the silk fabrics by using the preserved 18th-century remnants.[17]

text: When these results and high quality achieved were brought to the attention of the French Minister of Culture, he revived 18th-century weaving techniques so as to reproduce the silks used in the decoration of Versailles.[17] The two greatest achievements of this initiative are seen today in wall hangings used in the restoration of the chambre de la reine in the grand appartement de reine and the chambre du roi in the appartement du roi. While the design used for the chambre du roi was, in fact, from the original design to decorate the chambre de la reine, it nevertheless represents a great achievement in the ongoing restoration at Versailles. Additionally, this project, which took over seven years to achieve, required several hundred kilograms of silver and gold to complete.[18] One of the more costly endeavours for the museum and France's Fifth Republic has been to repurchase as much of the original furnishings as possible. However, because furniture with a royal provenance – and especially furniture that was made for Versailles – is a highly sought after commodity on the international market, the museum has spent considerable funds on retrieving much of the palace's original furnishings.[19]

text: 21st century[edit]

text: The Fifth Republic has enthusiastically promoted the museum as one of France's foremost tourist attractions, with recent figures stating that nearly five million people visit the château, and 8 to 10 million walk in the gardens, every year.[20][21] In 2003, a new restoration initiative – the "Grand Versailles" project – was started, which necessitated unexpected repair and replantation of the gardens, which had lost over 10,000 trees during Hurricane Lothar on 26 December 1999. The project will be on-going for the next seventeen years, funded with a state endowment of €135 million allocated for the first seven years. It will address such concerns as security for the palace and continued restoration of the bosquet des trois fontaines. Vinci SA underwrote the €12 million restoration project for the Hall of Mirrors, which was completed in 2006.[22]

text: Social history[edit]

text: Politics of display[edit]

text: On 6 May 1682, Versailles became officially the seat of the government of the kingdom of France, the home of the French King Louis XIV, and the location of the royal court. Symbolically, the central room of the long extensive symmetrical range of buildings was the King's Bedchamber (appartement du roi), which itself was centred on the lavish and symbolic state bed, set behind a rich railing. Indeed, even the principal axis of the gardens themselves was conceived to radiate from this fulcrum. All the power of France emanated from this centre: there were government offices here; as well as the homes of thousands of courtiers, their retinues and all the attendant functionaries of court.[citation needed] By requiring that nobles of a certain rank and position spend time each year at Versailles, Louis XIV prevented them from developing their own regional power at the expense of his own and kept them from countering his efforts to centralize the French government in an absolute monarchy.[citation needed]

text: At various periods before Louis XIV established absolute rule, France, like the Holy Roman Empire lacked central authority and was not the unified state it was to become during subsequent centuries.[citation needed] During the Middle Ages, French nobles were often more powerful than the King of France and, although technically loyal to him, they possessed their own provincial seats of power and government, the loyalty of culturally influential courts and armies, and the right to levy their own taxes on their subjects.[citation needed] Some families were so powerful they achieved international prominence and contracted marriage alliances with foreign royal houses to further their own political ambitions.[citation needed] Although nominally Kings of France, de facto royal power had at times been limited purely to the region around Paris.[citation needed]

text: Life at Court[edit]

text: Life at Versailles was determined by position, favour, and, above all, one's birth. The chateau was a sprawling cluster of lodgings for which courtiers vied and manipulated. Today, Versailles is seen as unparalleled in its magnificence and splendour, yet few know of the actual living conditions many of Versailles' privileged residents had to endure.[citation needed]. Many modern historians have compared the palace to a vast, crowded apartment block.[citation needed] Apart from the royal family, the majority of the residents were senior members of the household.[citation needed]

text: On each floor apartments of varying size, 350 in all, were arranged along tiled corridors and given a number and a key. Many courtiers traded lodgings and grouped themselves together with their allies, families or friends. The Noailles family took over so much of the northern wing's attic that floor was nicknamed rue de Noailles (Noailles Street).[23]

text: Louis XIV envisaged Versailles as a seat for all the Bourbons, as well as his troublesome nobles. These nobles were, so to say, placed within a "gilded cage".[24] Many of the apartments were far from luxurious with many nobles having to make do with one or two room apartments, forcing many of them to build or buy town-houses in Versailles proper while keeping their palace rooms for changes of clothes or entertaining guests, rarely sleeping there.[citation needed] Rooms at Versailles were immensely useful for ambitious courtiers, as they allowed palace residents easy access to the monarch.[citation needed]

text: Political and ceremonial functions[edit]

text: Two of the three treaties of the Peace of Paris (1783), in which the United Kingdom recognized the independence of the United States, were signed at Versailles.

text: After the French defeat in the Franco-Prussian War, with the Siege of Paris dragging on, the palace was the main headquarters of the Prussian army from 5 October 1870 until 13 March 1871. On 18 January 1871, Prussian King Wilhelm I was proclaimed German Emperor in the Hall of Mirrors and the German Empire was founded.[25]

text: After the First World War, it was the site of the opening of the Paris Peace Conference in 1919, also on 18 January. Germany was blamed for causing the First World War in the Treaty of Versailles, which was signed in the same room on 28 June 1919.

text: The palace, however, still serves political functions. Heads of state are regaled in the Hall of Mirrors; the bicameral French Parliament—consisting of the Senate (Sénat) and the National Assembly (Assemblée nationale)—meet in joint session (a congress of the French Parliament) in Versailles[26] to revise or otherwise amend the French Constitution, a tradition that came into effect with the promulgation of the 1875 Constitution.[28] For example, the Parliament met in joint session at Versailles to pass constitutional amendments in June 1999 (for domestic applicability of International Criminal Court decisions and for gender equality in candidate lists), in January 2000 (ratifying the Treaty of Amsterdam), and in March 2003 (specifying the "decentralized organization" of the French Republic).[26]

text: In 2009, President Nicolas Sarkozy addressed the global financial crisis before a congress in Versailles, the first time that this had been done since 1848, when Charles-Louis Napoleon Bonaparte gave an address before the French Second Republic.[29][30][31] Following the November 2015 Paris attacks, President Francois Hollande gave a speech before a rare joint session of parliament at the Palace of Versailles.[32] This was the third time since 1848 that a French president addressed a joint session of the French Parliament at Versailles.[33] The president of the National Assembly has an official apartment at the Palace of Versailles.[34]

text: Palace and grounds[edit]

text: Architecture[edit]

text: The palace that we recognize today was largely completed by the death of Louis XIV in 1715. The eastern facing palace has a U-shaped layout, with the corps de logis and symmetrical advancing secondary wings terminating with the Dufour Pavilion on the south and the Gabriel Pavilion to the north, creating an expansive cour d'honneur known as the Royal Court (Cour Royale). Flanking the Royal Court are two enormous asymmetrical wings that result in a facade of 402 metres (1,319 ft) in length.[35] Encompassing 67,000 square metres (721,182 sq ft) the palace has 700 rooms, more than 2,000 windows, 1,250 fireplaces and 67 staircases.[36]

text: The façade of the original lodge is preserved on the entrance front. Built of red brick and cut stone embellishments, the U-shaped layout surrounds a black-and-white marble courtyard. In the center, a 3-storey avant-corps fronted with eight red marble columns supporting a gilded wrought-iron balcony is surmounted with a triangle of lead statuary surrounding a large clock, whose hands were stopped upon the death of Louis XIV. The rest of the façade is completed with columns, painted and gilded wrought-iron balconies and dozens of stone tables decorated with consoles holding marble busts of Roman emperors. Atop the mansard slate roof are elaborate dormer windows and gilt lead roof dressings that were added by Hardouin-Mansart in 1679–1681.

text: Inspired by the architecture of baroque Italian villas, but executed in the French classical style, the garden front and wings were encased in white cut ashlar stone known as the enveloppe in 1661-1678. The exterior features an arcaded, rusticated ground floor, supporting a main floor with round-headed windows divided by reliefs and pilasters or columns. The attic storey has square windows and pilasters and crowned by a balustrade bearing sculptured trophies and flame pots dissimulating a flat roof.

text: Plan of the main floor (c. 1837, with north to the right), showing the Hall of Mirrors in red, the Hall of Battles in green, the Royal Chapel in yellow, and the Royal Opera in blue

text: Interior[edit]

text: Grands appartements (State Apartments)[edit]

text: As a result of Le Vau's enveloppe of Louis XIII's former hunting lodge transforming it, between 1631 and 1634, into a red brick and white stone small château, with a black tile roof, the king and the queen had new apartments in the new addition, known at the time as the château neuf. The grands appartements (Grand Apartments, also referred to as the State Apartments[37]) are known respectively as the grand appartement du roi and the grand appartement de la reine. They occupied the main or principal floor of the château neuf, with three rooms in each apartment facing the garden to the west and four facing the garden parterres to the north and south, respectively. Le Vau's design for the state apartments closely followed Italian models of the day, as evidenced by the placement of the apartments on the next floor up from the ground level—the piano nobile—a convention the architect borrowed from 16th- and 17th-century Italian palace design.[38]

text: The king's apartment consisted of an enfilade of seven rooms, each dedicated to one of the then known planets and their associated titular Roman deity. The queen's apartment formed a parallel enfilade with that of the grand appartement du roi. It served as the residence of three queens of France - Marie-Thérèse d'Autriche, wife of Louis XIV, Marie Leczinska, wife of Louis XV, and Marie-Antoinette, wife of Louis XVI. Additionally, Louis XIV's granddaughter-in-law, Princess Marie-Adélaïde of Savoy, duchesse de Bourgogne, wife of the Petit Dauphin, occupied these rooms from 1697 (the year of her marriage) to her death in 1712.[c] After the addition of the Hall of Mirrors (1678–1684) the king's apartment was reduced to five rooms (until the reign of Louis XV, when two more rooms were added) and the queen's to four.

text: Appartement du roi (King's Apartment)[edit]

text: The appartement du roi is a suite of rooms originally set aside for the personal use of Louis XIV in 1683. His successors, Louis XV and Louis XVI, used these rooms for such ceremonies as the lever and the coucher.

text: Petit appartement du roi (King's Private Apartment)[edit]

text: The petit appartement du roi is a suite of rooms that were reserved for the private use of the king. Occupying the site on which rooms were originally arranged for Louis XIII on the first floor of the château, the space was radically modified by Louis XIV. His successors, Louis XV and Louis XVI had these rooms drastically modified and remodeled for their personal use.

text: Petit appartement de la reine (Queen's Private Apartment)[edit]

text: The petit appartement de la reine is a suite of rooms that were reserved for the personal use of the queen. Originally arranged for the use of the Marie-Thérèse, consort of Louis XIV, the rooms were later modified for use by Marie Leszczyńska and finally for Marie-Antoinette.

text: Galerie des Glaces (Hall of Mirrors)[edit]

text: The Galerie des Glaces (Hall of Mirrors), is perhaps the most celebrated room in the château of Versailles. The length of the gallery is 230 feet (70 metres) and there are 17 wide arcaded mirrors. Elisabeth Vigée Le Brun painted 30 scenes as a testimony of early reign years of Louis XIV on the ceiling.[2] Setting for many of the ceremonies of the French Court during the Ancien Régime, the Galerie des Glaces has also inspired numerous copies and renditions throughout the world.

text: The room's construction began in 1678 and finished in 1689.

text: Chapels of Versailles[edit]

text: In the evolution of the palace, there have been five chapels. The current chapel, which was the last major building project of Louis XIV, represents one of the finest examples of French Baroque architecture and ecclesiastical decoration.

text: The palace chapel is located in the north wing and its construction started by Hardouin-Mansart in 1699 but the person who completed the work was de Corte. Daily meetings, wedding ceremonies and baptisms were held in this chapel until 1789.[2]

text: Royal Opera[edit]

text: Ange-Jacques Gabriel's Royal Opera (Opéra Royal) was perhaps the most ambitious building project of Louis XV for the château of Versailles. Completed in 1770, the Opéra was inaugurated at the time of the wedding festivities of Louis XV's grandson, the Dauphin, future Louis XVI, and Marie-Antoinette. On October 1789, a banquet for royal guardsmen was held in this place. The Opera served as a host to the National Assembly from 1871 until 1875 when the Third Republic was proclaimed.[2]

text: The princes' wing[edit]

text: The south wing of the palace was named "the princes' wing" when quarters were given to princes du sang (princes of the blood). The Battles Gallery designed by architects Frédéric Nepveu and Pierre-Léonard Fontaine is situated on the first floor. and the ground floor hosts the Hall of Congress in which Chamber of Deputies gathered in 1876-79.[2]

text: Museum of the History of France[edit]

text: In the 19th century the Museum of the History of France was founded in Versailles, at the behest of Louis-Philippe I, who ascended to the throne in 1830. The entire second floor (premier étage) of the Aile du Midi (South Wing) of the palace was transformed into the Galerie des Batailles to house the newly created collection of paintings and sculptures depicting milestones battles of French history. The collections display painted, sculpted, drawn and engraved images illustrating events or personalities of the history of France since its inception. The museum occupies the lateral wings of the Palace. Most of the paintings date back to the 19th century and have been created specially for the museum by major painters of the time such as Delacroix, Horace Vernet or François Gérard but there are also much older artworks which retrace French History. Notably the museum displays works by Philippe de Champaigne, Pierre Mignard, Laurent de La Hyre, Charles Le Brun, Adam Frans van der Meulen, Nicolas de Largillière, Hyacinthe Rigaud, Jean Antoine Houdon, Jean Marc Nattier, Elisabeth Vigée Le Brun, Hubert Robert, Thomas Lawrence, Jacques-Louis David, Antoine Jean Gros and also Pierre-Auguste Renoir.

text: Gallery[edit]

text:
Hall of Mirrors

Queen's bedchamber in the grand appartement de la reine

Galerie des Batailles

Chapel

Opéra

A Dripping Fountain, Versailles

La Galerie des Glaces, Versailles, 1927

Salon de la Paix, Versailles, 1927

text: Gardens of Versailles[edit]

text: Evolving with the château, the gardens of Versailles represent one of the finest extant examples of the jardin à la française created by André Le Nôtre.

text: Subsidiary structures[edit]

text: Located in proximity to the château, these smaller structures served the needs of the royal family and court officials during the Ancien Régime. They include the Ménagerie royale (1664), demolished; the Trianon de porcelaine (1670), demolished; the Grand Trianon or Trianon de marbre (Marble Trianon) (1689); the Petit Trianon (1768); and the Pavillon de la Lanterne (1787), a hunting lodge.

text: In popular culture[edit]

text: Madagascar 3 (2012) is an animated film in which sophisticated chimpanzees Mason and Phil dress up as "King of Versailles" in reference to the Palace of Versailles

text:
"The Palace of Versailles" is a song by singer-songwriter Al Stewart, detailing the French Revolution, The Terror, and Napoléon Bonaparte's military coup, from the perspective of "the lonely Palace of Versailles"
On 2 July 2005, the French Live 8 was held in the courtyard of Versailles

text:
In the Doctor Who episode, "Girl in the Fire Place" (2005), The Doctor met the Madame de Pompadour in the Palace of Versailles
Let Them Eat Cake, a 1999 BBC comedy starring Jennifer Saunders and Dawn French, is set within the Palace.
Versailles is a 2015 British-American-Franco-Canadian television series set during the construction of Versailles Palace during the reign of Louis XIV

text:
Assassin's Creed Rogue is set in Versailles at the end of the game
Assassin's Creed Unity is set in Versailles at the beginning of the game
Castlevania: Bloodlines is a Konami video game in which Versailles is the fifth stage

text: Gallery[edit]

text:
Panoramic view from the park

Panoramic view from the city

Garden facade from the southwest

Salle du Sacre with a view toward Salle des Gardes in the Queen's Grand Apartment

View of the upper southwest corner of the south wing

View of the Palace from the southern part of the Parterre d'Eau, with the bronze statue of the Rhône River by Jean-Baptiste Tuby (1687)

Marble Court


document_title: Mock strawberry

question_text: plant looks like strawberry but has yellow flowers

text: Mock strawberry

text:
Mock strawberry

Scientific classification

Kingdom:

Plantae

(unranked):

Angiosperms

(unranked):

Eudicots

(unranked):

Rosids

Order:

Rosales

Family:

Rosaceae

Subfamily:

Rosoideae

Genus:

Duchesnea

Species:

D. indica

Binomial name

Duchesnea indica(Andrews) Th.Wolf

tag: table

text: Duchesnea indica (sometimes called Potentilla indica), known commonly by the names mock strawberry, Indian strawberry, or false strawberry,[1] is a flowering plant in the family Rosaceae. It has foliage and an aggregate accessory fruit similar to that of a true strawberry. It has yellow flowers, unlike the white or slightly pink flowers of true strawberries. It is native to eastern and southern Asia, but has been introduced to many other areas as a medicinal and an ornamental plant.  It has been naturalized in many regions, including parts of the United States.[2][3][4]

text: The leaves are trifoliate, roughly veined beneath, dark green, and often persisting through the winter, arising from short crowns. The plant spreads along creeping stolons, rooting and producing crowns at each node. The yellow flowers are produced in mid spring, then sporadically throughout the growing season. The aggregate accessory fruits are white or red, and entirely covered with red achenes, simple ovaries, each containing a single seed. They are edible, but they have little overall flavor.[5]

text: Recent genetic evidence has shown that this genus is better included within Potentilla,[6] but currently most sources still list it in the genus Duchesnea.[7]

text: A poultice of the crushed leaves is used to treat skin ailments such as eczema.[1]

text: Images[edit]

text:
Duchesnea indica  - MHNT

Immature fruit

Blossom


document_title: 1980 eruption of Mount St. Helens

question_text: who was president when mt st helens erupted

text: 1980 eruption of Mount St. Helens

text: Build-up to the eruption[edit]

text: Mount St. Helens remained dormant from its last period of activity in the 1840s and 1850s until March 1980.[7] Several small earthquakes, apparently beginning on March 15, indicated that magma may have begun moving below the volcano.[8] On March 20, at 3:45 p.m. Pacific Standard Time (all times will be in PST or PDT), a shallow magnitude 4.2 earthquake (the initial reading was 4.1), centered below the volcano's north flank,[8] signaled the volcano's violent return from 123 years of hibernation.[9] A gradually building earthquake swarm saturated area seismographs and started to climax at about noon on March 25, reaching peak levels in the next two days, including an earthquake registering 5.1 on the Richter scale.[10] A total of 174 shocks of magnitude 2.6 or greater were recorded during those two days.[11]

text: Shocks of magnitude 3.2 or greater occurred at a slightly increasing rate during April and May with five earthquakes of magnitude 4 or above per day in early April, and eight per day the week before May 18.[9] Initially there was no direct sign of eruption, but small earthquake-induced avalanches of snow and ice were reported from aerial observations.

text: At 12:36 p.m. on March 27, phreatic eruptions (explosions of steam caused by magma suddenly heating groundwater) ejected and smashed rock from within the old summit crater, excavating a new crater 250 feet (75 m) wide[9] and sending an ash column about 7,000 feet (2,100 m) into the air.[11] By this date a 16,000-foot-long (4,900 m) eastward-trending fracture system had also developed across the summit area.[12] This was followed by more earthquake swarms and a series of steam explosions that sent ash 10,000 to 11,000 feet (3,000 to 3,400 m) above their vent.[9] Most of this ash fell between 3 and 12 miles (5 and 19 km) from its vent, but some was carried 150 miles (240 km) south to Bend, Oregon, or 285 miles (459 km) east to Spokane, Washington.[13]

text: A second, new crater and a blue flame were observed on March 29.[13][14] The flame was visibly emitted from both craters and was probably created by burning gases. Static electricity generated from ash clouds rolling down the volcano sent out lightning bolts that were up to 2 miles (3 km) long.[13] Ninety-three separate outbursts were reported on March 30,[13] and increasingly strong harmonic tremors were first detected on April 1, alarming geologists and prompting Governor Dixy Lee Ray to declare a state of emergency on April 3.[14] Governor Ray issued an executive order on April 30 creating a "red zone" around the volcano; anyone caught in this zone without a pass faced a $500 fine or six months in jail.[15] This precluded many cabin owners from visiting their property.

text: By April 7 the combined crater was 1,700 feet long by 1,200 ft wide and 500 ft deep (520×370×150 m).[16] A USGS team determined in the last week of April that a 1.5-mile-diameter (2.4 km) section of St. Helens' north face was displaced outward by at least 270 feet (82 m).[12] For the rest of April and early May this bulge grew by 5 to 6 feet (1.5 to 1.8 m) per day, and by mid-May it extended more than 400 feet (120 m) north.[12] As the bulge moved northward, the summit area behind it progressively sank, forming a complex, down-dropped block called a graben. Geologists announced on April 30 that sliding of the bulge area was the greatest immediate danger and that such a landslide might spark an eruption. These changes in the volcano's shape were related to the overall deformation that increased the volume of the volcano by 0.03 cubic miles (0.13 km3) by mid-May.[17] This volume increase presumably corresponded to the volume of magma that pushed into the volcano and deformed its surface. Because the intruded magma remained below ground and was not directly visible, it was called a cryptodome, in contrast to a true lava dome exposed at the surface.

text: On May 7, eruptions similar to those in March and April resumed, and over the next days the bulge approached its maximum size.[18] All activity had been confined to the 350-year-old summit dome and did not involve any new magma. A total of about 10,000 earthquakes were recorded prior to the May 18 event, with most concentrated in a small zone less than 1.6 miles (2.6 km) directly below the bulge.[17] Visible eruptions ceased on May 16, reducing public interest and consequently the number of spectators in the area.[19] Mounting public pressure then forced officials to allow 50 carloads of property owners to enter the danger zone on May 17 to gather whatever property they could carry.[19] Another trip was scheduled for 10 a.m. the next day.[19] Because that next day was Sunday, more than 300 loggers would not be working in the area. By the time of the climactic eruption, dacite magma intruding into the volcano had forced the north flank outward nearly 500 feet (150 m) and heated the volcano's groundwater system, causing many steam-driven explosions (phreatic eruptions).

text: Landslide and eruption[edit]

text: As May 18 dawned, Mount St. Helens' activity did not show any change from the pattern of the preceding month. The rate of bulge movement, sulfur dioxide emission, and ground temperature readings did not reveal any changes indicating a catastrophic eruption. USGS volcanologist David A. Johnston was on duty at an observation post approximately 6 miles (10 km) north of the volcano: as of 6 a.m., Johnston's measurements did not indicate any unusual activity.[6]

text:
Sound of the eruption of Mount St. Helens, as heard from 140 miles away

Amateur recording of a series of booms produced by the eruption, as heard from the town of Newport, Oregon (audio filtered and amplified).

Problems playing this file? See media help.

text: Suddenly, at 8:32 a.m., a magnitude 5.1 earthquake centered directly below the north slope triggered that part of the volcano to slide,[20] approximately 7–20 seconds (about 10 seconds seems most reasonable) after the shock.[6] The landslide, the largest in recorded history, travelled at 110 to 155 miles per hour (177 to 249 km/h) and moved across Spirit Lake's west arm. Part of it hit a 1,150-foot-high (350 m) ridge about 6 miles (10 km) north.[6] Some of the slide spilled over the ridge, but most of it moved 13 miles (21 km) down the North Fork Toutle River, filling its valley up to 600 feet (180 m) deep with avalanche debris.[20] An area of about 24 square miles (62 km2) was covered, and the total volume of the deposit was about 0.7 cubic miles (2.9 km3).[6]

text: Scientists were able to reconstruct the motion of the landslide from a series of rapid photographs by Gary Rosenquist, who was camping 11 miles (18 km) away from the blast.[6] Rosenquist, his party and his photographs survived because the blast was deflected by local topography 1 mile (1.6 km) short of his location.[21]

text: Most of St. Helens' former north side became a rubble deposit 17 miles (27 km) long, averaging 150 feet (46 m) thick; the slide was thickest at 1 mile (1.6 km) below Spirit Lake and thinnest at its western margin.[6] Thousands of trees were torn from the surrounding hillside after the lake was sloshed 800 feet (240 m) up the hillside. All the water in Spirit Lake was temporarily displaced by the landslide, sending 600-foot-high (180 m) waves crashing into a ridge north of the lake,[22] adding 295 feet (90 m) of new avalanche debris above the old lakebed, and raising its surface level by about 200 feet.[6] As the water moved back into its basin, it pulled with it thousands of trees felled by a super-heated wall of volcanic gas and searing ash and rock that had overtaken the landslide seconds before. More than three decades after the eruption, mats of floating dead trees remain on Spirit Lake and nearby St. Helens Lake; the mats change position with the wind.

text: Pyroclastic flows[edit]

text: Initial lateral blast[edit]

text: The landslide exposed the dacite magma in St. Helens' neck to much lower pressure, causing the gas-charged, partially molten rock and high-pressure steam above it to explode a few seconds after the landslide started. Explosions burst through the trailing part of the landslide, blasting rock debris northward. The resulting blast laterally directed the pyroclastic flow of very hot volcanic gases, ash and pumice formed from new lava, while the pulverized old rock hugged the ground, initially moving at 220 miles per hour (350 km/h) but quickly accelerating to 670 mph (1,080 km/h), and it might have briefly passed the speed of sound.[6][20]

text: Pyroclastic flow material passed over the moving avalanche and spread outward, devastating a fan-shaped area 23 miles across by 19 miles long (37 km × 31 km).[20] In total about 230 square miles (600 km2) of forest was knocked down,[20] and extreme heat killed trees miles beyond the blow-down zone. At its vent the lateral blast probably did not last longer than about 30 seconds, but the northward-radiating and expanding blast cloud continued for about another minute.

text: Superheated flow material flashed water in Spirit Lake and North Fork Toutle River to steam, creating a larger, secondary explosion that was heard as far away as British Columbia,[23] Montana, Idaho, and Northern California. Yet many areas closer to the eruption (Portland, Oregon, for example) did not hear the blast. This so-called "quiet zone" extended radially a few tens of miles from the volcano and was created by the complex response of the eruption's sound waves to differences in temperature and air motion of the atmospheric layers and, to a lesser extent, local topography.[6]

text: Later studies indicated that one-third of the 0.045 cubic miles (0.19 km3) of material in the flow was new lava, and the rest was fragmented, older rock.[23]

text: Lateral blast result[edit]

text: Everyone in the quiet zone could see the huge ash cloud that was sent skyward from St. Helens' northern foot. The near-supersonic lateral blast, loaded with volcanic debris, caused devastation as far as 19 miles (31 km) from the volcano. The area affected by the blast can be subdivided into three roughly concentric zones:[6]

text:
Direct blast zone, the innermost zone, averaged about 8 miles (13 km) in radius, an area in which virtually everything, natural or artificial, was obliterated or carried away.[6] For this reason, this zone also has been called the "tree-removal zone". The flow of the material carried by the blast was not deflected by topographic features in this zone. The blast released energy equal to 24 Megatons of TNT.
Channelized blast zone, an intermediate zone, extended out to distances as far as 19 miles (31 km) from the volcano, an area in which the flow flattened everything in its path and was channeled to some extent by topography.[6] In this zone, the force and direction of the blast are strikingly demonstrated by the parallel alignment of toppled large trees, broken off at the base of the trunk as if they were blades of grass mown by a scythe. This zone was also known as the "tree-down zone". Channeling and deflection of the blast caused strikingly varied local effects that still remained conspicuous after some decades. Where the blast struck open land directly, it scoured it, breaking trees off short and stripping vegetation and even topsoil, thereby delaying revegetation for many years. Where the blast was deflected so as to pass overhead by several metres, it left the topsoil and the seeds it contained, permitting faster revegetation with scrub and herbaceous plants, and later with saplings. Trees in the path of such higher-level blasts were broken off wholesale at various heights, whereas nearby stands in more sheltered positions recovered comparatively rapidly without conspicuous long-term harm.
Seared zone, also called the "standing dead" zone, the outermost fringe of the impacted area, a zone in which trees remained standing but were singed brown by the hot gases of the blast.[6]

tag: ol

text: By the time this pyroclastic flow hit its first human victims, it was still as hot as 360 °C (680 °F) and filled with suffocating gas and flying angular material.[23] Most of the 57 people known to have died in that day's eruption succumbed to asphyxiation while several died from burns.[6] Lodge owner Harry R. Truman was buried under hundreds of feet of avalanche material. Volcanologist David A. Johnston was one of those killed, as was Reid Blackburn, a National Geographic photographer. Robert Landsburg, another photographer, was killed by the ash cloud. He was able to protect his film with his body, and the surviving photos provided geologists with valuable documentation of the historic eruption.[24]

text: Later flows[edit]

text: Subsequent outpourings of pyroclastic material from the breach left by the landslide consisted mainly of new magmatic debris rather than fragments of preexisting volcanic rocks. The resulting deposits formed a fan-like pattern of overlapping sheets, tongues and lobes. At least 17 separate pyroclastic flows occurred during the May 18 eruption, and their aggregate volume was about 0.05 cubic miles (210,000,000 m3).[6]

text: The flow deposits were still at about 300 to 420 °C (572 to 788 °F) two weeks after they erupted.[6] Secondary steam-blast eruptions fed by this heat created pits on the northern margin of the pyroclastic-flow deposits, at the south shore of Spirit Lake, and along the upper part of the North Fork Toutle River. These steam-blast explosions continued sporadically for weeks or months after the emplacement of pyroclastic flows, and at least one occurred a year later, on May 16, 1981.[6]

text: Ash column[edit]

text: As the avalanche and initial pyroclastic flow were still advancing, a huge ash column grew to a height of 12 miles (19 km) above the expanding crater in less than 10 minutes and spread tephra into the stratosphere for 10 straight hours.[23] Near the volcano, the swirling ash particles in the atmosphere generated lightning, which in turn started many forest fires. During this time, parts of the mushroom-shaped ash-cloud column collapsed, and fell back upon the earth. This fallout, mixed with magma, mud and steam, sent additional pyroclastic flows speeding down St. Helens' flanks. Later, slower flows came directly from the new north-facing crater and consisted of glowing pumice bombs and very hot pumiceous ash. Some of these hot flows covered ice or water which flashed to steam, creating craters up to 65 feet (20 m) in diameter and sending ash as much as 6,500 feet (2,000 m) into the air.[25]

text: Strong high-altitude wind carried much of this material east-northeasterly from the volcano at an average speed of about 60 miles per hour (97 km/h). By 9:45 a.m. it had reached Yakima, Washington, 90 miles (140 km) away, and by 11:45 a.m. it was over Spokane, Washington.[6] A total of 4 to 5 inches (100 to 130 mm) of ash fell on Yakima, and areas as far east as Spokane were plunged into darkness by noon where visibility was reduced to 10 feet (3.0 m) and 0.5 inches (13 mm) of ash fell.[23] Continuing eastward, St. Helens' ash fell in the western part of Yellowstone National Park by 10:15 p.m. and was seen on the ground in Denver, Colorado, the next day.[23] In time, ash fall from this eruption was reported as far away as Minnesota and Oklahoma, and some of the ash drifted around the globe within about 2 weeks.

text: During the nine hours of vigorous eruptive activity, about 540,000,000 tons of ash fell over an area of more than 22,000 square miles (57,000 km2).[6] The total volume of the ash before its compaction by rainfall was about 0.3 cubic miles (1.3 km3).[6] The volume of the uncompacted ash is equivalent to about 0.05 cubic miles (210,000,000 m3) of solid rock, or about 7% of the amount of material that slid off in the debris avalanche.[6] By around 5:30 p.m. on May 18, the vertical ash column declined in stature, but less severe outbursts continued through the next several days.[26]

text: Ash properties[edit]

text: Generally, given that the way airborne ash is deposited after an eruption is strongly influenced by the meteorological conditions, a certain variation of the ash type will occur, as a function of distance to the volcano or time elapsed from eruption. The ash from Mount St. Helens is no exception, and hence the ash properties have large variations.[27]

text: Chemical composition[edit]

text: The bulk chemical composition of the ash has been found to be approximately 65% silicon dioxide, 18% aluminium oxide, 5% ferric oxide, 4% each calcium oxide and sodium oxide and 2% magnesium oxide. Trace chemicals were also detected, their concentrations varying as shown: 0.05–0.09% chlorine, 0.02–0.03% fluorine, and 0.09–0.3% sulphur.[27]

text: Index of refraction[edit]

text: The index of refraction, a number used in physics to describe how light propagates through a particular substance, is an important property of volcanic ash. This number is complex having both real and imaginary parts, the real part indicating how light disperses and the imaginary part indicating how light is absorbed by the substance.

text: It is known that the silicate particles have a real index of refraction ranging between 1.5 and 1.6 for visible light. However, there is a spectrum of colors associated with samples of volcanic ash, from very light to dark gray. This makes for variations in the measured imaginary refractive index under visible light.[28]

text: In the case of Mount St. Helens, the ash settled in three main layers on the ground:[27]

text:
the bottom layer was dark gray and was found to be abundant in older rocks and crystal fragments
the middle layer consisted of a mixture of glass shards and pumice
the top layer was ash consisting of very fine particles

text: For example, when comparing the imaginary part of the refractive index k of stratospheric ash from 15 km and 18 km from the volcano it has been discovered that they have similar values around 700 nm (around 0.009), while they differ significantly around 300 nm. Here, the 18 km (k was found to be around 0.009) sample was much more absorbent than the 15 km sample (k was found to be around 0.002).[28]

text: Mudslides flow downstream[edit]

text: The hot, exploding material also broke apart and melted nearly all of the mountain's glaciers along with most of the overlying snow. As in many previous St. Helens' eruptions, this created huge lahars (volcanic mudflows) and muddy floods that affected three of the four stream drainage systems on the mountain,[25] and which started to move as early as 8:50 a.m.[22] Lahars travelled as fast as 90 miles per hour (140 km/h) while still high on the volcano but progressively slowed to about 3 miles per hour (4.8 km/h) on the flatter and wider parts of rivers.[6] Mudflows from the southern and eastern flanks had the consistency of wet concrete as they raced down Muddy River, Pine Creek and Smith Creek to their confluence at the Lewis River. Bridges were taken out at the mouth of Pine Creek and the head of Swift Reservoir, which rose 2.6 feet (0.79 m)[25] by noon to accommodate the nearly 18,000,000 cubic yards (14,000,000 m3) of additional water, mud and debris.[6]

text: Glacier and snow melt mixed with tephra on the volcano's northeast slope to create much larger lahars. These mudflows traveled down the north and south forks of the Toutle River and joined at the confluence of the Toutle forks and the Cowlitz River near Castle Rock, Washington, at 1:00 p.m. Ninety minutes after the eruption, the first mudflow had moved 27 miles (43 km) upstream where observers at Weyerhaeuser's Camp Baker saw a 12-foot-high (4 m) wall of muddy water and debris pass.[22] Near the confluence of the Toutle's north and south forks at Silver Lake, a record flood stage of 23.5 feet (7.2 m) was recorded.[22]

text: A large but slower-moving mudflow with a mortar-like consistency was mobilized in early afternoon at the head of the Toutle River north fork. By 2:30 p.m. the massive mudflow had destroyed Camp Baker,[22] and in the following hours seven bridges were carried away. Part of the flow backed up for 2.5 miles (4.0 km) soon after entering the Cowlitz River, but most continued downstream. After traveling 17 miles (27 km) further, an estimated 3,900,000 cubic yards (3,000,000 m3) of material were injected into the Columbia River, reducing the river's depth by 25 feet (8 m) for a 4-mile (6 km) stretch.[22] The resulting 13-foot (4.0 m) river depth temporarily closed the busy channel to ocean-going freighters, costing Portland, Oregon, an estimated five million US dollars.[26] Ultimately more than 65 million cubic yards (50 million cubic metres) of sediment were dumped along the lower Cowlitz and Columbia Rivers.[6]

text: Aftermath[edit]

text: Direct results[edit]

text: The May 18, 1980, event was the most deadly and economically destructive volcanic eruption in the history of the United States.[6] Approximately fifty-seven people were killed directly from the blast and 200 houses, 47 bridges, 15 miles (24 km) of railways and 185 miles (298 km) of highway were destroyed; two people were killed indirectly in accidents that resulted from poor visibility, and two more suffered fatal heart attacks from shoveling ash.[29] U.S. President Jimmy Carter surveyed the damage and said it looked more desolate than a moonscape.[30][31] A film crew was dropped by helicopter on Mount St. Helens on May 23 to document the destruction. However, their compasses spun in circles and they quickly became lost.[32] A second eruption occurred the next day (see below), but the crew survived and were rescued two days after that. The eruption ejected more than 1 cubic mile (4.2 km3) of material.[33] A quarter of that volume was fresh lava in the form of ash, pumice and volcanic bombs while the rest was fragmented, older rock.[33] The removal of the north side of the mountain (13% of the cone's volume) reduced Mount St. Helens' height by about 1,280 feet (390 m) and left a crater 1 to 2 miles (2 to 3 km) wide and 2,100 feet (640 m) deep with its north end open in a huge breach.[33]

text: More than 4,000,000,000 board feet (9,400,000 m3) of timber was damaged or destroyed, mainly by the lateral blast.[6] At least 25% of the destroyed timber was salvaged after September 1980. Downwind of the volcano, in areas of thick ash accumulation, many agricultural crops, such as wheat, apples, potatoes and alfalfa, were destroyed. As many as 1,500 elk and 5,000 deer were killed, and an estimated 12 million[6] Chinook and Coho salmon fingerlings died when their hatcheries were destroyed. Another estimated 40,000 young salmon were lost when they swam through turbine blades of hydroelectric generators after reservoir levels were lowered along the Lewis River to accommodate possible mudflows and flood waters.[6]

text: In total Mount St. Helens released 24 megatons of thermal energy, 7 of which were a direct result of the blast. This is equivalent to 1,600 times the size of the atomic bomb dropped on Hiroshima.[34]

text: Disputed death toll[edit]

text: There is a minor controversy in regards to the exact death toll. The figure most commonly cited is fifty-seven. However, there are two points of dispute.

text: The first point regards two officially listed victims, Paul Hiatt and Dale Thayer. They were reported missing after the explosion. In the aftermath, investigators were able to locate individuals named Paul Hiatt and Dale Thayer who were alive and well. However, they were unable to determine who reported Hiatt missing, and the person who was listed as reporting Thayer missing claimed she wasn't the one who had done so. Since the investigators could not thus verify that they were the same Hiatt and Thayer who were reported missing, the names remain listed among the presumed dead.[35][36]

text: The second point regards three missing people who are not officially listed as victims: Robert Ruffle, Steven Whitsett and Mark Melanson. Cowlitz County Emergency Services Management lists them as "Possibly Missing — Not on [the official] List". According to Melanson's brother, in October 1983, Cowlitz County officials told his family that Melanson "is believed [...] a victim of the May 18, 1980, eruption" and that after years of searching, the family eventually decided "he's buried in the ash".[36]

text: Taking these two points of dispute into consideration, the direct death toll could be as low as fifty-five or as high as sixty. When combined with the four indirect victims mentioned earlier, those numbers range from fifty-nine to sixty-four.

text: Ash damage and removal[edit]

text: The ash fall created some temporary major problems with transportation, sewage disposal, and water treatment systems. Visibility was greatly decreased during the ash fall, closing many highways and roads. Interstate 90 from Seattle to Spokane was closed for a week and a half.[6] Air travel was disrupted for between a few days and two weeks, as several airports in eastern Washington shut down because of ash accumulation and poor visibility. Over a thousand commercial flights were cancelled following airport closures.[6] Fine-grained, gritty ash caused substantial problems for internal-combustion engines and other mechanical and electrical equipment. The ash contaminated oil systems and clogged air filters, and scratched moving surfaces. Fine ash caused short circuits in electrical transformers, which in turn caused power blackouts.

text: Removing and disposing of the ash was a monumental task for some Eastern Washington communities. State and federal agencies estimated that over 2,400,000 cubic yards (1,800,000 m3) of ash, equivalent to about 900,000 tons in weight, were removed from highways and airports in Washington.[6] The ash removal cost $2.2 million and took 10 weeks in Yakima.[6] The need to remove ash quickly from transport routes and civil works dictated the selection of some disposal sites. Some cities used old quarries and existing sanitary landfills; others created dump sites wherever expedient. To minimize wind reworking of ash dumps, the surfaces of some disposal sites were covered with topsoil and seeded with grass. In Portland, the mayor eventually threatened businesses with fines if they failed to remove the ash from their parking lots.[37]

text: Cost[edit]

text: A refined estimate of $1.1 billion ($2.74 billion in 2007 dollars[38]) was determined in a study by the International Trade Commission at the request of the United States Congress.[6] A supplemental appropriation of $951 million for disaster relief was voted by Congress, of which the largest share went to the Small Business Administration, U.S. Army Corps of Engineers and the Federal Emergency Management Agency.[6]

text: There were also indirect and intangible costs of the eruption. Unemployment in the immediate region of Mount St. Helens rose tenfold in the weeks immediately following the eruption, and then returned to near-normal levels once timber-salvaging and ash-cleanup operations were underway. Only a small percentage of residents left the region because of lost jobs owing to the eruption.[6] Several months after May 18, a few residents reported suffering stress and emotional problems, even though they had coped successfully during the crisis. Counties in the region requested funding for mental health programs to assist such people.[6]

text: Initial public reaction to the May 18 eruption dealt a nearly crippling blow to tourism, an important industry in Washington. Not only was tourism down in the Mount St. Helens–Gifford Pinchot National Forest area, but conventions, meetings and social gatherings also were cancelled or postponed at cities and resorts elsewhere in Washington and neighboring Oregon not affected by the eruption. The adverse effect on tourism and conventioneering, however, proved only temporary. Mount St. Helens, perhaps because of its reawakening, has regained its appeal for tourists. The United States Forest Service and the State of Washington opened visitor centers and provided access for people to view the volcano's devastation.[6]

text: Later eruptions[edit]

text: St. Helens produced an additional five explosive eruptions between May and October 1980. Through early 1990 at least 21 periods of eruptive activity had occurred. The volcano remains active, with smaller, dome-building eruptions continuing into 2008.

text: An eruption occurred on May 25, 1980, at 2:30 a.m. that sent an ash column 9 miles (14 km) into the atmosphere.[33] The eruption was preceded by a sudden increase in earthquake activity and occurred during a rainstorm. Erratic wind from the storm carried ash from the eruption to the south and west, lightly dusting large parts of western Washington and Oregon. Pyroclastic flows exited the northern breach and covered avalanche debris, lahars and other pyroclastic flows deposited by the May 18 eruption.[33]

text: At 7:05 p.m. on June 12, a plume of ash billowed 2.5 miles (4.0 km) above the volcano. At 9:09 p.m. a much stronger explosion sent an ash column about 10 miles (16 km) skyward.[39] This event caused the Portland area, previously spared by wind direction, to be thinly coated with ash in the middle of the annual Rose Festival.[40] A dacite dome then oozed into existence on the crater floor, growing to a height of 200 feet (61 m) and a width of 1,200 feet (370 m) within a week.[39]

text: A series of large explosions on July 22 broke more than a month of relative quiet. The July eruptive episode was preceded by several days of measurable expansion of the summit area, heightened earthquake activity, and changed emission rates of sulfur dioxide and carbon dioxide. The first hit at 5:14 p.m. as an ash column shot 10 miles (16 km) and was followed by a faster blast at 6:25 p.m. that pushed the ash column above its previous maximum height in just 7.5 minutes.[39] The final explosion started at 7:01 p.m. and continued for over two hours.[39] When the relatively small amount of ash settled over eastern Washington, the dome built in June was gone.[41]

text: Seismic activity and gas emission steadily increased in early August, and on August 7 at 4:26 p.m., an ash cloud slowly expanded 8 miles (13 km) into the sky.[41] Small pyroclastic flows came through the northern breach and a weaker outpouring of ash rose from the crater. This continued until 10:32 p.m. when a second large blast sent ash high into the air, proceeding due north.[41] A second dacite dome filled this vent a few days later.

text: Two months of repose were ended by an eruption lasting from October 16 to 18. This event obliterated the second dome, sent ash 10 miles (16 km) in the air and created small, red-hot pyroclastic flows.[41] A third dome began to form within 30 minutes after the final explosion on October 18, and within a few days, it was about 900 feet (270 m) wide and 130 feet (40 m) high. In spite of the dome growth next to it, a new glacier formed rapidly inside the crater.

text: All of the post-1980 eruptions were quiet dome-building events, beginning with the December 27, 1980, to January 3, 1981, episode. By 1987 the third dome had grown to be more than 3,000 feet (910 m) wide and 800 feet (240 m) high.[41]

text: Further eruptions occurred over a few months between 1989 and 1991.

text: The 2004–08 volcanic activity of Mount St. Helens has been documented as a continuous eruption with a gradual extrusion of magma at the Mount St. Helens volcano. Starting in October 2004 there was a gradual building of a new lava dome. The new dome did not rise above the caldera created by the 1980 eruption. This activity lasted until January 2008.

text: Summary table[edit]

text:
Eruption summary
May 18, 1980, eruption of Mount St. Helens

Elevation of summit:
Before eruption: 9,677 ft (2,950 m)
After eruption: 8,363 ft (2,549 m)
Total removed: 1,314 ft (401 m)

Crater dimensions:
East-West: 1.2 mi (1.9 km)
North-South: 1.8 mi (2.9 km)
Depth: 2,084 ft (635 m)

Crater floor elevation:
6,279 ft (1,914 m)

Eruption
Date:
May 18, 1980

Time of initial blast:
8:32 a.m. Pacific Daylight Time (UTC−7)

Eruption trigger:
A magnitude 5.1 earthquake about 1 mi (1.6 km) beneath the volcano

Landslide and
debris avalanche
Area covered:
23 sq mi (60 km2)

Volume:
(uncompacted deposits)
0.67 cu mi (2.8 km3)

Depth of deposit:
Buried North Fork Toutle River to average depth of 150 ft (46 m) with a maximum depth of 600 ft (183 m)

Velocity:
70 to 150 mph (113 to 241 km/h)

Lateral blast
Area covered:
230 sq mi (596 km2); reached 17 mi (27 km) northwest of the crater

Volume of deposit:
(uncompacted deposits)
0.046 cu mi (0.19 km3)

Depth of deposit:
From about 3 ft (1 m) at volcano to less than 1 in (2.5 cm) at blast edge

Velocity:
At least 300 mph (483 km/h)

Temperature:
As high as 660 °F (349 °C)

Energy release:
24 megatons thermal energy (7 by blast, rest through release of heat)

Trees blown down:
4,000,000,000 board feet (9,400,000 m3) of timber (enough to build about 300,000 two-bedroom homes)

Human fatalities:
55-60 (direct); 4 (indirect); 59-64 (total)

Lahars
Velocity:
About 10 to 25 mph (16 to 40 km/h) and over 50 mph (80 km/h) on steep flanks of volcano

Damaged:
27 bridges, nearly 200 homes. Blast and lahars destroyed more than 185 mi (298 km) of highways and roads and 15 mi (24 km) of railways.

Effects on Cowlitz River:
Reduced carrying capacity at flood stage at Castle Rock from 76,000 cu ft (2,200 m3) per second to less than 15,000 cu ft (420 m3) per second.

Effects on Columbia River:
Reduced channel depth from 40 to 14 ft (12 to 4 m); stranded 31 ships in upstream ports

Eruption column
and cloud
Height:
Reached about 80,000 ft (24,400 m) in less than 15 minutes

Downwind extent:
Spread across U.S. in 3 days; circled Earth in 15 days

Volume of ash:
(based on uncompacted deposits)
0.26 cu mi (1.1 km3)

Ash fall area:
Detectable amounts of ash covered 22,000 sq mi (57,000 km2)

Ash fall depth:
10 in (25 cm) at 10 mi (16 km) downwind (ash and pumice)
1 in (2.5 cm) at 60 mi (97 km) downwind
0.5 in (1.3 cm) at 300 mi (482.8 km) downwind

Pyroclastic flows
Area covered:
6 sq mi (16 km2); reached as far as 5 mi (8 km) north of crater

Volume and depth:
(volume based on uncompacted deposits)
0.029 cu mi (0.12 km3); multiple flows 3 to 30 ft (1 to 9 m) thick; cumulative depth of deposits reached 120 ft (37 m) in places

Velocity:
Estimated at 50 to 80 mph (80 to 130 km/h)

Temperature:
At least 1,300 °F (700 °C)

Other
Wildlife:
The Washington State Department of Game estimated nearly 7,000 big game animals (deer, elk and bear) perished as well as all birds and most small mammals. Many burrowing rodents, frogs, salamanders and crawfish managed to survive because they were below ground level or water surface when the disaster struck.

Fisheries:
The Washington Department of Fisheries estimated that 12 million Chinook and Coho salmon fingerlings were killed when hatcheries were destroyed. Another estimated 40,000 young salmon were lost when forced to swim through turbine blades of hydroelectric generators as reservoir levels along the Lewis River were kept low to accommodate possible mudflows and flooding.

Brantley and Myers, 1997, Mount St. Helens – From the 1980 Eruption to 1996: USGS Fact Sheet 070–97, accessed 2007-06-05; and Tilling, Topinka, and Swanson, 1990, Eruption of Mount St. Helens – Past, Present, and Future: USGS General Interest Publication, accessed 2007-06-05.

Table compiled by Lyn Topinka, USGS/CVO, 1997