Volcanology (also spelled vulcanology) encompasses the scientific investigation of volcanoes, lava, magma, and associated geological, geophysical, and geochemical processes, collectively known as volcanism. Its etymology traces back to the Latin term vulcan, referring to Vulcan, the ancient Roman deity of fire.
A volcanologist is a geological scientist specializing in the eruptive dynamics and genesis of volcanoes, alongside their contemporary and historical eruptive events. These specialists routinely conduct field expeditions to volcanic sites, particularly active ones, to document eruptions and gather samples of eruptive materials, such as tephra (e.g., ash or pumice), rock, and lava. A primary research objective involves the forecasting of eruptions; while no precise methodology currently exists, the ability to predict or forecast such events, akin to seismic predictions, holds significant potential for preserving human life.
Contemporary Volcanology
The inaugural volcanological observatory, the Vesuvius Observatory, was established in 1841 within the Kingdom of the Two Sicilies. Progress in volcanology has necessitated more than mere systematic observation, fundamentally depending on the synthesis of knowledge from diverse disciplines, including geology, tectonics, physics, chemistry, and mathematics. Significant breakthroughs often emerge following advancements in other scientific domains. For instance, the investigation into radioactivity began in 1896, with its subsequent application to plate tectonics theory and radiometric dating developing approximately five decades later. Since 1841, numerous other innovations across fluid dynamics, experimental physics and chemistry, mathematical modeling techniques, instrumentation, and various other scientific fields have been integrated into volcanological research.
Investigative Methodologies
Seismic monitoring employs seismographs strategically positioned in proximity to volcanic regions to detect elevated seismicity during volcanic episodes. A particular focus is placed on identifying long-period harmonic tremors, which indicate the subterranean movement of magma within volcanic conduits.
Monitoring of surface deformation incorporates geodetic methodologies, encompassing measurements of leveling, tilt, strain, angles, and distances, facilitated by instruments such as tiltmeters, total stations, and electronic distance meters (EDMs). Additionally, this involves Global Navigation Satellite System (GNSS) observations and Interferometric Synthetic Aperture Radar (InSAR). Surface deformation serves as an indicator of magma upwelling, where an augmented magma supply leads to the formation of bulges on the volcanic edifice's surface.
Volcanic gas emissions are monitored using specialized instrumentation, including portable ultraviolet spectrometers (e.g., COSPEC, now largely replaced by miniDOAS), which analyze the presence of gases like sulfur dioxide, or through infrared spectroscopy (FTIR). Elevated gas emission rates, and especially shifts in gas compositions, can serve as precursors to an imminent volcanic eruption.
Thermal variations are tracked using thermometers and by observing alterations in the thermal characteristics of volcanic lakes and vents, which can signify impending activity.
Satellite technology is extensively employed for volcanic surveillance, offering the advantage of monitoring vast geographical areas with relative ease. These platforms are capable of quantifying the dispersion of ash plumes, exemplified by the 2010 Eyjafjallajökull eruption, and detecting SO2 emissions. Furthermore, InSAR and thermal imaging facilitate the monitoring of expansive, sparsely inhabited regions where the deployment and maintenance of ground-based instrumentation would be economically prohibitive.
Additional geophysical methodologies, encompassing electrical, gravimetric, and magnetic observations, involve tracking fluctuations and abrupt shifts in resistivity, gravity anomalies, or magnetic anomaly patterns. These indicators can suggest volcano-induced faulting and the ascent of magma.
Stratigraphic analysis involves the examination and dating of tephra and lava deposits to delineate volcanic eruption patterns, including estimations of activity cycles and eruption magnitudes.
Compositional analysis has proven highly effective in classifying volcanoes based on type and magma origin. This includes correlating volcanoes with specific hotspot mantle plumes, determining mantle plume melting depths, reconstructing the history of recycled subducted crust, matching tephra deposits to their respective source volcanoes, and elucidating the formation and evolution of magma reservoirs. This analytical approach has been further substantiated through real-time sampling.
Eruption Forecasting
Some of the aforementioned techniques, when combined with modeling, have proven effective in forecasting certain eruptions, exemplified by the 1991 evacuation around Mount Pinatubo, which potentially saved 20,000 lives. Short-term forecasts typically utilize seismic or multi-monitoring data, whereas long-term predictions involve studying the historical patterns of local volcanism. However, eruption forecasting encompasses not only the prediction of an eruption's initial onset time but also the assessment of its potential magnitude and its progression once it has commenced.
History
Volcanology possesses a long and rich history. The earliest documented evidence of a volcanic eruption is potentially a wall painting from approximately 7,000 BCE, discovered at the Neolithic site of Çatalhöyük in Anatolia, Turkey. This painting has been interpreted as depicting a double-peaked volcano in eruption, with a settlement situated at its base, though this interpretation is currently debated by archaeologists. The depicted volcano is hypothesized to be either Hasan Dağ or its smaller adjacent peak, Melendiz Dağ.
Ancient mythology
The classical civilizations of Greece and the early Roman Empire attributed volcanic activity to the presence or actions of various deities. Mythological accounts posited that the giant Enceladus was buried beneath Etna by the goddess Athena as punishment for rebellion against the gods. Roman poet Virgil, in the Aeneid, linked the mountain's subterranean rumblings to Enceladus's tormented cries, its flames to his breath, and its tremors to his struggle against imprisonment. Euripides theorized that Hephaestus, the deity of fire, resided beneath Mount Etna, where he forged Zeus's weaponry. Aeschylus identified Etna as the prison of Typhon, who had engaged Zeus in the Titanomachy. Diodorus Siculus, in his discussion of the 425 BCE eruption of Etna, connected the phenomenon to the abduction of Persephone.
Greco-Roman philosophy
The Greek philosopher Empedocles (c. 490-430 BCE) postulated that the world was composed of the four classical elements: earth, air, fire, and water. Plato asserted the existence of subterranean rivers through which channels of hot and cold waters flowed. In the depths of the earth, a vast river of fire, the Pyriphlegethon, was believed to supply all terrestrial volcanoes. In Meteorology, Aristotle regarded Earth as a living organism prone to convulsions and spasms. He attributed subterranean fire to "the...friction of the wind when it plunges into narrow passages."
Wind was a central element in volcanic theories until the 16th century, following Anaxagoras's fifth-century BCE proposition that eruptions resulted from powerful winds. Lucretius, a Roman philosopher, posited that Etna was entirely hollow, with its subterranean fires fueled by a strong wind circulating close to sea level. Ovid theorized that volcanic flames were sustained by "fatty foods," ceasing when this fuel was depleted. Vitruvius argued that sulfur, alum, and bitumen nourished the deep-seated fires. Pliny the Elder observed that earthquakes often preceded an eruption; he perished during the 79 CE eruption of Vesuvius while conducting investigations at Stabiae. His nephew, Pliny the Younger, provided comprehensive accounts of the eruption that claimed his uncle's life, attributing the fatality to toxic gas exposure. Consequently, such eruptions are designated as Plinian, honoring both authors.
Middle Ages
The thirteenth-century Dominican scholar Restoro d'Arezzo dedicated two full chapters (11.6.4.6 and 11.6.4.7) of his influential treatise La composizione del mondo colle sue cascioni to exploring the genesis of Earth's internal energy. Restoro asserted that the Earth's interior was intensely hot and, echoing Empedocles, posited a molten core, explaining volcanic eruptions as the ascent of molten rock to the surface.
Renaissance observations
During the Renaissance, observers such as Bernard Palissy, Conrad Gessner, and Johannes Kentmann (1518–1568) demonstrated a profound interest in the Earth's nature, behavior, origin, and history. Numerous theories regarding volcanic activity emerged during the late sixteenth and mid-seventeenth centuries. Georgius Agricola contended that solar rays, a concept later echoed by Descartes, bore no relation to volcanic phenomena. Agricola posited that pressurized vapor instigated eruptions of 'mountain oil' and basalt. Johannes Kepler conceptualized volcanoes as conduits for the Earth's 'tears and excrement,' expelling bitumen, tar, and sulfur. Descartes, asserting that God instantaneously created the Earth, described its formation in three distinct layers: fiery depths, a water layer, and the atmosphere. He further proposed that volcanoes originated at points where solar rays penetrated the Earth's surface.
Southern Italian volcanoes captivated naturalists following the Renaissance, which facilitated the rediscovery of classical descriptions by authors such as Lucretius and Strabo. Vesuvius, Stromboli, and Vulcano offered prime opportunities for investigating the characteristics of volcanic phenomena. Italian natural philosophers residing near these volcanoes authored extensive and scholarly works on the topic. Giovanni Alfonso Borelli's 1669 account of Mount Etna's eruption became a seminal informational resource, alongside Giulio Cesare Recupito's description of the 1631 Mount Vesuvius eruption (published in 1632 and subsequent editions), and Francesco Serao's 1737 report on the Vesuvius eruption (also published in 1737, with French and English editions).
The Jesuit Athanasius Kircher (1602–1680) observed eruptions of Mount Etna and Stromboli, subsequently exploring Vesuvius's crater. He then published his hypothesis of an Earth possessing a central fire, linked to numerous other fires fueled by burning sulfur, bitumen, and coal. This perspective was articulated in his work Mundus Subterraneus, wherein volcanoes were conceptualized as a form of safety valve.
The origins of these phenomena were extensively debated within numerous theories of the Earth published during the century following 1650. These theorists, though not direct observers, synthesized existing observations with Newtonian, Cartesian, Biblical, or animistic scientific principles to construct diverse, comprehensive systems. Within these frameworks, volcanic eruptions and earthquakes were commonly associated with vast subterranean caverns where flammable vapors could accumulate and eventually ignite. Thomas Burnet proposed that a significant portion of the Earth itself was combustible, containing readily ignitable pitch, coal, and brimstone. William Whiston's theory posited that subterranean air was requisite for ignition, whereas John Woodward emphasized the crucial role of water. Athanasius Kircher asserted that these caverns and heat sources were profoundly deep, extending towards the Earth's core. Conversely, other scholars, particularly Georges Buffon, considered them relatively superficial, with volcanic fires situated high within the volcanic cone itself. Several authors, most notably Thomas Robinson, conceptualized the Earth as a living organism, interpreting its internal heat, earthquakes, and eruptions as manifestations of life. Although this animistic philosophy declined by the late seventeenth century, its influence persisted into the eighteenth century. Scientific discourse grappled with concepts such as the combustion of pyrite with water, the solidification of rock from bitumen, and the formation of rock from water (Neptunism). Given that all known volcanoes at the time were situated near water bodies, the interaction between the sea and land was frequently invoked to elucidate volcanism.
Interaction with Religion and Mythology
Numerous tribal legends concerning volcanoes originate from the Pacific Ring of Fire and the Americas, often attributing violent eruptions to supernatural or divine forces. In Māori mythology, Taranaki and Tongariro were lovers who became enamored with Pihanga, leading to a bitter, jealous conflict. To this day, some Māori avoid residing along the direct alignment between Tongariro and Taranaki, fearing a resurgence of this ancient dispute. Within Hawaiian religion, Pele ( Pel-a; [ˈpɛlɛ]) is revered as the goddess of volcanoes and remains a prominent figure in Hawaiian mythology. Her name has been adopted for several scientific terms, including Pele's hair, Pele's tears, and Limu o Pele (Pele's seaweed). Furthermore, a volcano on Jupiter's moon Io bears the name Pele.
Saint Agatha serves as the patron saint of Catania, a city situated near Mount Etna, and remains a highly revered exemplar of virgin martyrs from Christian antiquity. In 253 CE, merely a year after her violent demise, the cessation of a Mount Etna eruption was attributed to her divine intervention. Despite this, Catania suffered near-total destruction during the 1169 Mount Etna eruption, resulting in over 15,000 fatalities. Nonetheless, Saint Agatha was invoked once more during the 1669 Etna eruption and again for an outbreak that threatened the town of Nicolosi in 1886. The practice of invoking and interacting with the saint in Italian folk religion, often characterized by a reciprocal or bargaining approach in prayerful exchanges, has been linked, following the tradition of James Frazer, to ancient pagan beliefs and practices.
The 1660 eruption of Vesuvius deposited twinned pyroxene crystals and ash onto neighboring villages. These crystals, resembling crucifixes, were interpreted as a miraculous intervention by Saint Januarius. In Naples, the relics of Saint Januarius are customarily paraded through the city during every significant eruption of Vesuvius. Records of these processions, alongside the 1779 and 1794 diaries of Father Antonio Piaggio, enabled the British diplomat and amateur naturalist Sir William Hamilton to compile a comprehensive chronology and description of Vesuvius's eruptions.
Notable volcanologists
- Plato (428–348 BC)
- Pliny the Elder (23–79 AD)
- Pliny the Younger (61 – c. 113 AD)
- George-Louis Leclerc, Comte de Buffon (1707–1788)
- James Hutton (1726–1797)
- Déodat Gratet de Dolomieu (1750–1801)
- George Julius Poulett Scrope (1797–1876)
- Giuseppe Mercalli (1850–1914)
- Thomas Jaggar (1871–1953), founder of the Hawaiian Volcano Observatory
- Haroun Tazieff (1914–1998), advisor to the French Government and Jacques Cousteau
- George P. L. Walker (1926–2005), pioneering volcanologist who transformed the subject into a quantitative science
- Haraldur Sigurdsson (born 1939), Icelandic volcanologist and geochemist
- Katia and Maurice Krafft (1942–1991 and 1946–1991, respectively), died at Mount Unzen in Japan, 1991
- David A. Johnston (1949–1980), killed during the 1980 eruption of Mount St. Helens
- Harry Glicken (1958–1991), died at Mount Unzen in Japan, 1991
Gallery
Collections
University College London houses the United Kingdom's most extensive collection of rare books on volcanology, a bequest made in 1914 by the physician and volcanologist Henry James Johnston Lavis. The collection's earliest works include Censorinus's De die natali (1503), Beroaldus's Opusculum de terremotu et pestilentia (1505), and Elisius's De balneis (c.1510). Notably, 44 volumes within the collection document the 1631 eruption of Mount Vesuvius, which represented the volcano's most significant eruption since 79 AD.
Global Volcanism Program
- Global Volcanism Program
- GNS Science (formerly the Institute of Geological and Nuclear Sciences) (in New Zealand)
- Igneous rock
- Kiyoo Mogi, developer of the Mogi model of volcano deformation
- Tephrochronology
- Volcano
- Volcano Number
- Volcanism
References
European Volcanological Society
- European Volcanological Society
- United States Geological Survey- Volcanic Hazards Program
- What is a volcanologist?
- Vulcanology on In Our Time at the BBC
- World Organization of Volcano Observatories
- Strother, French (April 1915). "Frank A. Perret, Volcanologist." The World's Work: A History of Our Time. XXIX: 688–706. .Strother, French (May 1915). "Frank A. Perret, Volcanologist (Concluded)." The World's Work: A History of Our Time. XXX: 85–98. .Source: TORIma Academy Archive