The Dr. Bill FAQ

What is lava, and how is it heated?

A caller asked about lava, and where the heat required to create it came from. The short answer is that the center of the earth is extremely hot and molten, and has been since the Earth was formed billions of years ago. Closer to the Earth’s crust, that heat will actually melt rock and other material beneath the surface, turning it into magma. This magma occasionally finds its way to the earth’s surface through cracks and fissures in the crust, which are often created by the movement of the continental plates, both at the boundaries of the plates, and at other stress points. Once the magma reaches the Earth’s surface, it is then termed lava, where it will cool and turn into a black, mineral-rich material as hard as other rock. When this ”rock” is worn down into dirt, it tends to produce extremely fertile soil, making for excellent agriculture. I’ve found several resources on the Internet for learning more about volcanoes, including:

Mount St. Helens: A General Slide Set

This page describes the process of Mount St. Helens’ rebirth as an active volcano. Even though this volcano didn’t produce the more familiar lava flows (its flows were of mud, and instead of producing a fountain of magma, it produced a fountain of ash), it shows the incredible destructive force volcano can produce.

NASA EOS IDS Volcanology Team

There are currently 29 EOS IDS Teams. Most are focussed on studying the oceans, atmosphere, biogeochemical cycles, and hydrology. Only 2 are focussed on geologic processes (our Volcanology Team and the team of Bryan Isacks at Cornell: Climate, Erosion and Tectonics in the Andes and Other Mountain Systems). Dr. Ghassem Asrar (the EOS Program Scientist) presented the following list as the role of the EOS IDS teams (January 11, 1994, at the EOS-IWG meeting).

Ask a Geologist

You can ask a USGS Geologist just about any question you can think of here.

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