Re: When was the first known volcano?

   Hi Davon,

   We know that some volcanic eruptions occured 600.000 years ago at 
yellowstone (Wyoming) and 700.000 years ago at Long Valley (California) 
both in USA. We know it because the volcanic rocks that were formed by 
these eruptions have been identified. But it doesn't mean that events are 
the oldest.

   There are volcanic eruptions since the Earth was formed and the 
eruptions were much more intensive and largely distributed around the 
world. The Earth was cooling then the number of volcanic eruptions began 
to decrease because the crust was being formed.

   Actually in any one year, about 50 individual volcanoes erupt and 2,500 
have been active within the last 10,000 years.

   Sr. Willian Hamilton was the first volcanologist and he studied the 
vesuvius eruptions in the middle of XVIII century.

   You can see this references to complete your study about volcanoes:

Press, F. and Siever, R. -1994- Understanding the Earth. Freeman and 
Company, New York, 594 pp.

Tazieff, H. -1975- The Making of the Earth. Gordon & Cremonesi, London, 96 
pp.

Francis, P. -1993- Volcanoes. Claredon Press, Oxford, 443 pp.

   Regards,

   Emilson P. Leite
   IAG/USP - Brazil.