Everything about Volcanology totally explained
Volcanology (also spelled
vulcanology) is the study of
volcanoes,
lava,
magma, and related
geological phenomena. The term
volcanology is derived from the
Latin word
vulcan, the
Roman god of fire. Volcanology is a branch of
geology.
A
volcanologist is a person who studies the formation of volcanoes, and their current and historic eruptions. Volcanologists frequently visit volcanoes, especially active ones, to observe
volcanic eruptions, collect eruptive products including
tephra (such as
ash or
pumice),
rock and
lava samples. One major focus of enquiry is the prediction of eruptions; there's currently no accurate way to do this, but predicting eruptions, like predicting earthquakes, could save many lives.
History of volcanology
Volcanology has a very extensive history. The earliest known recording of a volcanic eruption is recorded by a c.6000 BC wall painting of a volcanic eruption. The painting, from the Neolithic site at Çatal Höyük (also known as
Çatalhöyük Çatal Hüyük) in
Anatolia,
Turkey, shows a twin peaked volcano in eruption, with a town at its base. The volcano is probably
Hasan Dag, which has two peaks.
Mythical explanations
The classical world of Greece and the early
Roman Empire explained volcanoes as the work of the gods as science and alchemy had no explanation for their existence. Grecian myths and tales tell of
Atlantis, a fabled island which sank into the sea. Plato (428-348 B.C.) told of the disappearance of a vast island and its powerful civilization, the Atlanteans, in two of his dialogues,
Critias and
Timaeus. It is now considered that the island of
Thera, now
Santorini, in the Aegean Sea, was destroyed by a tremendous series of volcanic explosions around 1620 B.C., with ash falls of up to a foot deep recorded in Turkey. The explosion of Thera sent colossal tidal waves, estimated at 100 feet height, racing across the Aegean, and the southern coast of Crete. Other recordings of the Thera eruption spawned Greek myths, namely the
Deucalion, in which
Poseidon, god of the sea, took revenge upon
Zeus by inundating
Attica,
Argolis,
Salonika,
Rhodes and the coast of
Lycia (Turkey) to
Sicily.
Greeks also considered that
Hephaestus, the god of fire, sat below the volcano
Etna, forging the weapons of Zeus. His minions, the
cyclops with their single staring eye, may be an allegory to the round craters and cones of a volcano. Indeed, the Greek word used to describe volcanoes was
etna, or
hiera, after
Heracles, the son of Zeus. The Roman poet
Virgil, in interpreting the Greek mythos, held that the hero
Enceladus was buried beneath Etna by the goddess Athena as punishment for disobeying the gods; the mountain's rumblings were his tormented cries, the flames his breath and the tremors his railing against the bars of his prison. Enceladus' brother
Mimas was buried beneath
Vesuvius by Hephaestus, and the blood of other defeated giants welled up in the Phlegrean Fields surrounding Vesuvius.
Tribal legends of volcanoes abound from the
Pacific Ring of Fire and the Americas, usually invoking the forces of the supernatural or the divine to explain the violent outbursts of volcanoes.
Taranaki and
Tongariro, according to Māori mythology, were lovers who fell in love with
Pihanga, and a spiteful jealous fight ensued. Māori won't to this day live between Tongariro and Taranaki for fear of the dispute flaring up again.
Greco-Roman science
The first attempt at a scientific explanation of volcanoes was undertaken by the Greek philosopher
Empedocles (c. 490-430 B.C.), who saw the world divided into four elemental forces, of Earth, Air, Fire and Water. Volcanoes, Empedocles maintained, were the manifestation of Elemental Fire. Plato contended that channels of hot and cold waters flow in inexhaustible quantities through subterranean rivers. In the depths of the earth snakes a vast river of fire, the
Pyriphlegethon, which feeds all the world's volcanoes. Aristotle considered underground fire as the result of "the...friction of the wind when it plunges into narrow passages."
Wind would play a key role in explanations of volcanoes until the 16th century.
Lucretius, a Roman philosopher, claimed Etna was completely hollow and the fires of the underground driven by a fierce wind circulating near sea level. Ovid believed that the flame was fed from "fatty foods" and eruptions stopped when the food ran out.
Vitruvius contended that sulfur, alum and bitumen fed the deep fires. Observations by
Pliny the Elder noted the presence of earthquakes preceded an eruption; he died in the eruption of
Vesuvius in 79 AD while investigating it at
Stabiae. His nephew,
Pliny the Younger gave detailed descriptions of the eruption in which his uncle died, attributing his death to the effects of toxic gases. Such eruptions have been named
Plinian in honour of the two authors.
Christian mythology
The study of volcanology wasn't advanced much between the days of Plato and Hutton. The Christian world explained volcanoes by a multitude of prescientific notions, but it was also thought they were the work of
Satan or the wrath of God, and only saintly miracles could avert their wrath. For this reason the
relics of
Saint Agatha were paraded in front of lava advancing on
Catania in 253 A.D., and miraculously the lava clove in two (down two valleys) and spared the town. Unfortunately the relics of St. Agatha proved ineffective in 1669, with the loss of much of Catania to Etna's lava.
In 1660 the eruption of Vesuvius rained twinned
pyroxene crystals and ash upon the nearby villages. The twinned pyroxene crystals resembled the crucifix and this was interpreted as the work of
Saint Januarius. In
Naples, the relics of St Januarius are paraded through town at every major eructation of Vesuvius. The register of these processions allowed British diplomat and amateur naturalist
Sir William Hamilton to document Vesuvius' eruptions, one of the first few 'scientific' studies of the eruptive history of a volcano.
Renaissance observations
Renaissance descriptions of volcanoes vastly improved the state of knowledge, despite the resistance of the Church to scientific explorations of the natural world, especially those which were at odds with Biblical teachings. Nevertheless,
nuees ardentes were described from the Azores in 1580.
Georgius Agricola argued the rays of the sun, as later proposed by
Descartes had nothing to do with volcanoes. Agricola believed vapor under pressure caused eruptions of 'mointain oil' and basalt.
Jesuit
Athanasius Kircher (1602–1680) witnessed eruptions of Mount Etna and Stromboli, then visited the crater of Vesuvius and published his view of an Earth with a central fire connected to numerous others caused by the burning of sulfur, bitumen and coal.
Johannes Kepler considered volcanoes as conduits for the tears and excrement of the Earth, voiding bitumen, tar and sulfur. Descartes, pronouncing that God had created the Earth in an instant, declared he'd done so in three layers; the fiery depths, a layer of water, and the air. Volcanoes, he said, were formed where the rays of the sun pierced the earth.
Science wrestled with the ideas of the combustion of
pyrite with water, that rock was solidified bitumen, and with notions of rock being formed from water (
Neptunism). Of the volcanoes then known, all were near the water, hence the action of the sea upon the land was used to explain volcanism.
Modern volcanology
Seismic observations using
seismographs deployed near volcanic areas, watching out for increased seismicity during volcanic events, in particular looking for long period harmonic tremors which signal
magma movement through volcanic conduits.
Surface
deformation monitoring includes the use of geodetic techniques such as leveling, tilt, strain, angle and distance measurements through tiltmeters, total stations and EDMs. This also includes
GNSS observations and InSAR. Surface deformation indicates magma upwelling: increased magma supply produces bulges in the volcanic center's surface.
Gas emissions are monitored with equipment such as the Correlation Spectrometer (COSPEC) which analyzes the presence of
volcanic gases such as
sulfur dioxide. Increased emissions possibly signal an impending volcanic eruption.
Other
geophysical techniques (electrical, gravity and magnetic observations) include monitoring fluctuations and sudden change in resistivity, gravity anomalies or magnetic anomaly patterns which may indicate volcano-induced faulting and magma upwelling.
[
Stratigraphic analyses includes analyzing tephra and lava deposits and dating these to give volcano eruption patterns, with estimated cycles of intense activity and size of eruptions.][
]Famous volcanologists
See also
Further Information
Get more info on 'Volcanology'.
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