Ch 9 Volcanoes and Eathquakes

Most earthquakes occur

• along the plate boundary.

• in the middle of plates.

• in the central part of a continent.

Where do most volcanoes erupt?

• along sliding plate boundaries

• in the middle of tectonic plates

• along divergent plate boundaries

The total energy released by an earthquake is best measured on the

• Richter scale.

• Modified Mercalli scale.

• moment magnitude scale.

What have scientists learned more about by studying earthquakes?

• the age and structures of Hawaiian hot spots

• the composition and structure of Earth's interior

• the locations and compositions of major volcanoes

Volcanoes form when magma

• flows through the crust.

• changes in compsition.

• hardens beneath the surface.

Magma that is rich in gases will form a volcano

• that erupts explosively.

• with gently sloping sides.

• whose lava has a low viscosity.

Which is NOT a volcanic hazard?

• pyroclastic flows in populated areas

• sulfur dioxide gases from an eruption

• subduction of tectonic plates at a boundary

volcano with gentle slopes made from basalt

• cinder cone

• compsosite

• shield

large, steep-sided volcano make of lava and ash

• cinder cone

• composite

• shield

small, steep-sided volcano made of basalt

• cinder cone

• composite

• shield