Week 8:

What type of plate boundary does Mount St. Helens occur at?

Convergent (ocean-continent subduction)

Explosive silica-rich volcanoes will be located mostly at ______.

Convergent plate boundaries with subduction zones

What type of plate boundary does the axial seamount occur at?

Divergent

Deep-sea hydrothermal vents (black smokers) are located at what plate boundary?

Divergent boundaries of the mid-ocean ridge

How are volcanic eruptions predicted?

- Earthquakes are monitored - Gases are monitored - Uplift and tilt of the ground surface is monitored

Which of the following hazards occurred with the Mount St. Helens eruption?

- Landslide - Lava - Pyroclastic flow - Lahar - Ash

At which plate boundary types do volcanoes form?

- Divergent - Convergent (ocean-ocean subduction) - Convergent (ocean-continent subduction)

Which of the following hazards occurred with the Axial Seamount eruption?

Lava

A __________ is a volcanic hazard arising from a collapsing eruption column that runs downhill at high speeds (>100 mph). These are associated with explosive eruptions and a mix of lava, lapilli, pumice, ash, and hot gases.

Pyroclastic flow

The largest type of volcano is called a _______ volcano and is characterized by broad, low-angle flanks, a small vent or groups of vents at the top, and basaltic magma.

Shield volcano

The least explosive volcano with the lowest silica content is a ______.

Shield volcano

Which type of volcano is the Axial Seamount?

Shield volcano

A _______ volcano has steep flanks, symmetrical cone shapes, distinct craters, and a silica-rich magma that results in an explosive eruption style.

Stratovolcano

Which type of volcano is Mount St. Helens?

Stratovolcano

A caldera is a _____________.

large, steep-walled depression caused by the collapse of a magma chamber