Volcanoes - The power of a major volcanic eruption

Figure 10-2. In some eruptions, the mountaintop collapses into the empty portions of the magma
chamber beneath the mountain, forming a caldera.

Figure 10-3. Crater Lake is located in a caldera that formed after a violent eruption of Mount
Mazama. How long ago did that eruption occur?

Figure 10-5. The bleak landscape of the Mount St. Helens blast area is a grim reminder of the
death-dealing nature of volcanoes.



Figure 10-6. These erosion patterns were photographed in the Valley of the 10,000 Smokes, Alaska.
How and when was this valley formed?











Figure 10-7. (A) Mauna Kea, Hawaii, shield cone.
                       (B) Cinder cone in a volcanic field near Sonora, Mexico.
                       (C) Mount Fuji. Japan, composite cone.


Figure 10-8. Many volcanoes are located around the edge of the Pacific Ocean and form what is
called the Circum-Pacific Ring of Fire. Where are many volcanoes of the Atlantic Ocean?





Figure 10-9. Surtsey, off the southern coast of Iceland, is located along the mid-ocean ridge, a
site of much volcanic activity.

Fariel, R. - Hinds, R. - Berey, D.: Earth Science, Addison-Wesley 1987

Mid-Ocean Ridges

The Mid-Ocean Ridge system, snaking its way between the continents, is more than 56,000 kilometers
long. This series of mountains and valleys marks where the Earth’s crustal plates are moving apart.



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