Exam 5: Volcanoes and Volcanism

The three main types of volcanoes are:

Why does most volcanism at spreading ridges go undetected?

The eruption of Mount St.Helens was one of the largest and deadliest in the world in historic times.

Besides monitoring,what other knowledge helps geologists determine what to expect for eruptions from a given volcano?

Composite volcanoes are also known as ____________________ and are composed of both ____________________ flows and ____________________ material.

How do columnar joints form?

Describe shield volcanoes.What are they built of? Where are they found?

The chemical composition of all lavas is the same.

What is the difference between an active volcano and a dormant volcano?

Pyroclastic sheet deposits are thin lava flows that often exhibit columnar jointing.

Why are the volcanoes of Hawaii shield volcanoes the same as spreading ridges?

Describe the volcanoes that form the Hawaiian Islands,especially on the island of Hawaii.

Volcanoes were named for Vulcan,the Roman deity of fire.

The dominant gas emitted from volcanoes is ____________________.

How did recent eruptions of Mount Pinatubo in the Philippines and Kilauea in Hawaii differ?

What is a lahar?

Distinguish aa from pahoehoe flows.

How is the behavior of gases different in a quiet and an explosive eruption?

Which magma type usually erupts from fissures?

An eruption of a viscous,felsic magma is likely to form a lahar.