Category Archives: FAQ

These are recent or frequent questions about volcanoes, volcanology, or who knows what!

Do Hawaiian volcanoes explode like Mt. St. Helens?

Hawaiian Volcanoes will not explode like Mount St. Helens. Mount St. Helens magma is more viscous. Therefore gas cannot escape as readily, resulting in explosive eruptions. One index of explosivity is volume of eruption. Since the start of the current … Continue reading

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What are some good things that volcanoes do?

That’s a good question. I guess the main good effect that volcanoes have on the environment is to provide nutrients to the surrounding soil. Volcanic ash often contains minerals that are beneficial to plants, and if it is very fine … Continue reading

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What is the greatest amount of lava that has ever erupted from any volcano?

Probably the largest historic lava flow was erupted in Iceland from part of the Grimsvotn volcano system called Laki. Thorvaldur Thordarson and Steve Self calculated a lava flow volume of 14.7 cubic kilometers of lava.

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What’s the most recent eruption of Vesuvius and will it erupt again?

  Photo by Italian Air Force from Green and Short (1971). Vesuvius has erupted about three dozen times since 79 A.D., most recently from 1913-1944. The 1913-1944 eruption is thought to be the end of an eruptive cycle that began … Continue reading

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Why are there so many volcanoes in the Pacific Northwest and Alaska?

  The distribution of volcanoes in the northwest and Alaska is the result of plate tectonics. In the northwest, the oceanic Farallon Plate is being pushed beneath (subducted) the continental margin of the North American Plate. When the subducted plate … Continue reading

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How do volcanoes affect the atmosphere and climate?

This photo shows the large white billowing eruption plume from Rabaul being carried in a westerly direction by the weak prevailing winds. At the base of the eruption column is a layer of yellow-brown ash being distributed by lower level … Continue reading

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How does a thermocouple measure the temperature of lava without melting?

A thermocouple works on the principle that the electrical resistance at the point where two wires of different composition join, is very sensitive to the temperature. So…a thermocouple consists of two wires joined to an electrical source. Current passes through … Continue reading

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How do volcanoes help scientists learn about the Earth’s interior?

The deepest samples of the Earth’s interior brought up from drill holes come from a depth of 12 km . . . . volcanoes provide direct samples of the Earth’s interior from much greater depths . . at least 100 … Continue reading

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How do Volcanologists predict volcanic eruptions?

The prediction of volcanic eruptions is difficult because, to be of practical use, they must be made before eruptions! Its a lot easier to see patterns in monitoring data after an eruption has occurred. But great progress has been made … Continue reading

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What tools do Volcanologists use to study volcanoes?

Volcanologists use many different kinds of tools including instruments that detect and record earthquakes (seismometers and seimographs), instruments that measure ground deformation (EDM, Leveling, GPS, tilt), instruments that detect and measure volcanic gases (COSPEC), instruments that determine how much lava … Continue reading

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