SEGway
is a public resource center of the Science Information Infrastructure
a partner in NASA's Learning Technologies Program.LTP
Copyright © 1998, The Regents of the University of
California. All rights reserved.
What caused this crater?
All craters are the result of tremendous explosions.
What makes them differ from each other is what caused the explosion.
Around the earth today, many people live in areas with lots of volcanic
activity. In fact, this seems to have been the case for even ancient
humans. Archeologists find evidence of human habitation buried in
volcanic ash all over the world. You may wonder why people would
want to live near volcanoes. The fact is, the volcano brings many minerals to the
surface that make the soil very rich and fertile. Because
people lived near volcanoes, they were very familiar with volcanic craters.
Volcanoes have many sizes and shapes, but can usually be
divided into three main types: cinder cones, stratovolcanoes, and shield
volcanoes. The shape of the crater depends on how violent the eruptions
were. There are, however, other craters that do not seem
to be volcanic in nature. It was more difficult for scientists to explain
these, because they had not been able to see the crater form.
You are looking at an image of a volcanic caldera called Aniakchak.
This aerial view, looking east of Aniakchak caldera, is one of the most spectacular
volcanoes on the Alaska Peninsula. Formed during a catastrophic ash-flow
producing eruption about 3,400 years ago, Aniakchak caldera is about 10 km (6 miles)
across and averages 500 m (1,640 ft) in depth. Voluminous postcaldera eruptive
activity has produced a wide variety of volcanic landforms and deposits within the caldera.
The volcano is located in Aniakchak National Monument and Preserve, Alaska, which is
administered by the National Park Service. Photograph by M. Williams, National Park
Service, 1977. USGS Digitial Data Series 96-040, Neal and McGimsey.
The Science Museum of Virginia
This page last updated February 8, 1998