Facts and Figures
Volcanoes come into being because of fissures in the earth's crust, from which magma, gases, rocks, and ashes can erupt. There are about 1500 potentially active volcanoes around the world. Like Etna and Stromboli in Italy, some have been in continuous eruption for more than 2,000 years. Three hundred sixty volcanoes exploded in the 20th century, one of the most famous being Mount Etna, the largest active volcano in Europe.
Specialization
There are four significant types of Volcanologists: Physical Volcanologists study and gather data on the actual processes and deposits of volcanic eruptions. Geophysicists deal with volcanic seismicity, gravity, and magnetics; they spend time outdoors studying various geological features, or indoors using computers for calculations and modeling. Geodesic Volcanologists study dead or dormant volcanoes to figure out how explosions and lava flow produce new and different earth formations. Geochemists analyze the structure, composition, and processes that make up the earth and volcanic products, and the distribution of chemical elements in rocks and minerals.
The Ground Reality
While many may think that a Volcanologist’s work consists solely of the exciting, adventurous work performed close to an erupting volcano crater, they would be wrong. Most Volcanologists study the remains of either dead or dormant volcanoes or those that may be active or “reawakening.”
Leveraging Technology
Volcanologists use robots to reach areas that are too dangerous for humans. They fly past volcanoes in planes or use satellites to look at them from space for any changes or signs when they might erupt next.
Armor of the 21st Century
Volcanologists wear protective suits with a metal coating that reflects the volcano’s heat, leaving the person inside cool. The suit can resist temperatures of up to 3,000°F (1,650°C). Heatproof boots help them walk across the red-hot lava while gas masks connected to air tanks allow them to breathe when the air around them is full of poisonous gas.
Volcanologists wear gloves made of asbestos, an insulating material that blocks heat, to pick up red-hot lava. They also wear hard hats, which protect against volcanic “bombs,” chunks of rock that shoot out of the volcano.
Tools and Techniques of the Trade
A special set of tools is needed to study volcanoes. It includes a magnifying glass that Volcanologists use to see the fine details in volcanic rocks. Seismometers detect and record volcanic activity.
Electronic tiltmeters and satellite photography to assess ground deformation, instruments to determine the amount of lava generated, and GPS form part of the tool kit. Volcanologists use the Volcanic Explosivity Index (VEI) to measure eruptions.
Trivia
The term “volcano” derives from the Latin word “Vulcan.” According to Greek and Roman mythology, Vulcan was the blacksmith of the Roman gods, and the word “volcano” honors and represents this Roman “God of Fire.”
Hot lava fragments and dust clouds erupting from Vulcano’s island in the Mediterranean Sea were believed to be Vulcan’s forge beating out thunderbolts for other gods. Ancient Greeks also believed in a god of fire that lived beneath this volcanic mountain known as Mt. Etna.
During the Middle Ages, many people thought volcanoes were the entrance to the fiery underworld.
The higher a volcano reaches into the sky, the more forceful its eruptions may become.
Types of Volcanoes
There are mainly three types of volcanoes. Shield volcanoes, usually non-explosive, have a low viscosity lava flow that runs wide, creating a shield shape with smooth sloping flanks, built by numerous layers over time. Stratovolcanoes or composite volcanoes can erupt explosively, reaching high in the sky and spewing dangerous ash, rocks, and lava. Cinder cones, smaller in size, and with short-lived eruptions, are most common. They rarely reach 300 meters in height, have steep sides, grow rapidly, usually from a single eruption cycle, and typically have a crater at the summit.
Pumice & Obsidian - Useful Volcanic Products
A pumice stone is a light-colored frothy volcanic rock that floats on water and it evolves from gas-filled lava. As the ejected lava shoots through the air during an eruption, it cools down. The gases that escape leave behind a porous rock that is ground up for use in soaps, abrasive cleaners, and polishes.
Obsidian, a glossy, natural volcanic glass, is produced when lava cools too quickly for crystals to form. The process is similar to glass manufacturing in factories, in which silica rocks like sand and quartz are melted and rapidly cooled in water. Usually black or very dark green, but also found in an almost transparent state, obsidian was used to make ancient cutting tools as well as weapons such as arrowheads, knives, and spearheads. In modern times, doctors use it as a scalpel to perform highly sensitive eye surgery.