Volcanoes can be either active, dormant or extinct. While active volcanoes erupt regularly, dormant volcanoes erupted in the past, but do not now; and extinct volcanoes have never erupted and scientists do not expect that they will. Cinder cones often form on other volcanoes. 500 Volcanoes around the world. There are about 500 volcanoes all over the world with about.

US Volcanoes and Current Activity Alerts. 2015 - 100th Anniversary of the 1915 Lassen Peak Eruption. The National Volcano Early Warning System plans to closely monitor threatening volcanoes. Current monitoring data from USGS volcano observatories. Ash hazards information and guidance for homes, businesses, and communities. Frequently updated real-time images of several U.

What is a volcano? Is a place where ash, gases, and molten rock from deep underground erupt on the surface. Also refers to the mountain of erupted rock and ash that often accumulates at such a place. It rises because it is less dense than the surrounding rock. Rising magma can collect below or inside a volcano in a region called a. If magma accumulates at a high enough rate, the volcano erupts almost continuously.

An associated bilingual, interactive, multimedia DVD brings hands-on curriculum to life.