History of volcanology

The history of the Volcanologie is related to the will that with the man to control the untameable forces of nature or at least to seek to avoid the damage of them.

Antiquity

See also: Volcan#Croyances and myths related to the volcanos, Beliefs and myths related to the volcanos

Volcanology, as a description of a volcanic phenomenon, was born with the Neolithic with the execution from a mural from a Volcan in eruption at two tops, probably the Mont Hassan, with Çatal Hüyük (Turkey) and going back to 6000 av. J. - C.

In the first civilizations, in particular at the Greek and the Roman , the volcanos and their eruptions is associated with divine demonstrations. It will be the same in the Christianisme which regard them as the work of Satan and the signs for divine anger.

With the O C, the Greek philosopher Empédocle d' Agrigente divides the world into Four elements fondamentaux : air, water, ground and fire, the last being represented by the volcanos.

Plato affirmed that rivers of warm water and cold traversed the interior of the Ground and that a vast river of central fire, the Pyriphlégéthon , fed all the volcanos of the Earth. Aristote explained the presence of this underground fire as “… the friction of the wind when it is engulfed in narrow passages. ” Lucrèce, a Roman philosopher, protested him that the Etna was completely hollow and that its fires were fed by a powerful wind circulating close to the sea level. Ovide thought that the eruptions were fed by “rich food” and that they ceased when this one had suddenly missed. Vitruve affirmed that underground fires were maintained by Soufre, Alun and Bitume. The idea of a paramount role of the wind as source of the volcanic eruptions will perdurera until the 16th century.

In 79, Pline Old the reports and describes the beginning of the eruption of the Vesuvius, noticing in particular that Séisme S precedes the beginning by an eruption. Wanting to go to more close to the events, it is killed by one of many the volcanic clouds which descended the sides of the Volcan and destroyed Pompéi. Its nephew, Pline the Young person, not having been able to accompany his uncle, makes a precise description of the eruption whose type will bear the name of both hommes : eruption plinienne. However, this description does not constitute an attempt at scientific explanation of the phenomenon.

Prescientific rebirth and theories

With the Rebirth, many theories are born but they must be compatible with the Dogme S of the Catholic church under penalty of being discredited.

Georgius Agricola proposes that the eruptions are caused by Steam under pressure. Johannes Kepler regards the volcanos as conduits rejecting the tears and waste of the Ground (the Soufre, the Bitume and the Goudron).

Descartes, while agreeing with the Genesis, declares that the Earth is made of three couches : a layer of air and a layer of water supported by burning depths. The volcanos would then have been formed when the rays of the Sun bored the Earth.

Many theories implemented water in volcanicity because the only volcanos known at the time were located near the sea.

At the 18th century, the naturalist and British ambassador William Hamilton benefitted from her stay with Naples during 36 years to document and study the eruptions of the Vesuvius. Its observations are regarded as the first scientific step of explanation of volcanicity. It publishes a book, “ Campi Phlaegraei, Observations one the Volcanos off the Two Sicilies ”, composed of many notes and sketch of its observations of ground.

A few years later, Italian Lazzaro Spallanzani makes attempts dissolve pieces of Basalte to find the origin of the Lave.

At the 18th century, two schools affrontent : the neptunists think that the contact of water on the Pyrite ignites layers of coal which dissolve the surrounding rocks whereas the plutonists affirms that there exists a mass of rock in fusion in the depths of the Earth and who arises at certain places.

In 1831, French Constant Prévost, of return of the Italian island of Julia, brings back the evidence of the formation of the Volcan s : they are born from a successive material stacking. This discovery puts an end to the confrontation between two théories : one affirmed that the volcanos were formed by successive layers, the other which they were only one ground heaving.

At the time, the Vesuvius is the volcano more studied. Other explorers start to study various volcanos: Bory of Saint-Vincent to the Piton of the Furnace in 1804, Alexandre de Humboldt with the Guagua Pichincha and the Chimborazo between 1799 and 1804 and counts 407 volcanos in 1846, the Santorin is studied by several geologists.

Because of regular activity of Vesuvius, a Observatoire volcanologic is built on its slopes in 1841 and of the Sismographe S are installed there.

In 1883, the eruption of the Krakatoa concentrates all the efforts of the volcanologists on this volcano. The eruption is analyzed like its effets : shock wave, effects climatic, etc the projections carried out made it possible to the geologists to reconsider the eruption of the Tambora which occurred in 1815.

In 1902, the eruption of the Peeled Mountain of the Martinique, total destruction of the town of Saint-Pierre and 28 000 dead causes stupor in metropolis. The catastrophe will be relayed in the newspapers with many photographs. Alfred Lacroix will be elected by the Academy of Science to include/understand the reasons of the catastrophe, in particular the growth of the Dôme of lava which crumbled. Two years later, it will publish a work which still refers and will take part in the creation of a Observatoire volcanologic.

Modern volcanology

In 1912, Alfred Wegener proposes the theory of the Plate tectonics to explain the continental drift and volcanicity. Although imperfect and partly distorts, its theory revolutionizes the perception which the geologists have and the volcanologists of volcanicity because it makes it possible to unify the majority of the phenomena geophysics. She was supplemented in the Années 1960 in particular with the introduction of the concept of Radioactivité into the origin of the internal heat of the Earth and the discovery of the magnetic anomalies into sea-beds. The geologists note, prove and admit whereas assembly lines, Volcan S and seismicity are distributed in a precise way on the surface of the Earth and are correlated.

Progress in Sismologie also benefits volcanology with the description from the plane from Benioff, different the discontinuities, the internal structure of sphere, etc the Plate tectonics proposes to the volcanologists a comprehensive view internal phenomena with the Earth with the continental drift, the Subduction and the divergence, the currents of Convection of the coat, etc Seuls remain certain volcanos which cannot stick with this theory. The volcanologists then develop the theory hot spots to explain the presence of volcanos in the middle of the lithospheric plates.

During the 20th century, Haroun Tazieff explores the volcanos of the whole world and is interested in particular in the Etna. It will improve of many measuring instruments which are still used today and will take part in the development and the installation of plans of evaluation of the volcanic risks and evacuation of the populations.

Katia and Maurice Kraft brings back as for them many photographs, films and extracts sound of more than 150 volcanos and publishes many books which contribute to the popularization of volcanology and of the Volcan S. They also took part in the development of plans of evaluation of the volcanic risks.

Appendices

Reference