Exam 5: Volcanoes and Volcanism

Shield volcanoes are composed largely of lavas of ____________________ composition; they commonly have slopes that are ____________________,and their eruptions tend to be ____________________ in explosivity.

Pyroclastic sheet deposits were formed by enormous ash falls.

Nuee ardentes erupt from ____.

The type of volcano that is the most common in the two major volcanic belts on Earth is ____________________.

Earth is the only body in our solar system that is volcanically active.

Pahoehoe is lava erupted by Hawaiian volcanoes that has a(n)____________________ viscosity and a(n)____________________ appearance.

Pyroclastic material that is less than 2 mm in diameter is called ____________________.Particles ranging from 2 to 64 mm in diameter are known as ____________________,while ____________________ are pieces larger than 64 mm in diameter.

Would you rather be chased by a pahoehoe flow or an aa flow? Explain.

Ozone depletion in the stratosphere is caused by

Lavas of ____________________ composition are more likely to produce lava domes.

The volcanic explosivity index (VEI)is intended to do what?

The one place on earth where mid-ocean ridge volcanism occurs above sea level is ____________________.

How could you distinguish a volcanic crater from a caldera?

One common but dangerous gas emitted from volcanoes,which is responsible for many deaths in Cameroon,is ____________________.

Briefly explain why volcanism occurs at subduction zones.

Sometimes the pyroclastic material that flows from a volcano is so hot that it fuses together to form a deposit known as ____________________.

Which type of volcano is Mt.St.Helens?

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

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

The ozone hole is the region of depleted stratospheric ozone that is found over the equatorial region.