Oceanic Hot Spots

A Chain of Volcanoes is created by the moving plate:

• The hotspot stays in one place while the plate moves over it

• Click here for a visualization

Examples of Lava Flows on Kilauea

Magma Type? Silica? Explosive?

Magma Formation

Lava

Landform

Plate Tectonics

Where on Earth

Basaltic LOW Rarely

Increase in temperature

Flows: Pahoehoe, Aa, Pillow

Does not occur at a plate boundary

Shield Volcano, Chain of Islands

Hawaii, Iceland

Continental Hot Spots

YellowstoneAbout 600,000 years ago:

– HUGE volcanic eruptions occurred in Yellowstone, emptying a large underground magma chamber.

– Volcanic debris spread for thousands of square miles in a matter of minutes.

– The roof of this chamber collapsed, forming a giant smoldering pit.

– This caldera was 30 miles (45 km) across, 45 miles (75 km) long, and several thousand feet deep.

– Eventually the caldera was filled with lava.

15-13mya

Obsidian: Volcanic glass are common rhyolitic flows

The Grand Canyon of Yellowstone is made out of rhyolite.

Basalt flows can also occur at continental hot spots because some of the magma comes directly from the

mantle.

Magma Type? Silica? Explosive?

Magma Formation

Lava

Landform

Plate Tectonics

Where on Earth

Rhyolitic HIGH Extremely

Increase in temperature

MAINLY Rhyolitic Flows (Obsidian), but also Basaltic flows.

In Yellowstone this formed a caldera.

Does not occur at a plate boundary.

Yellowstone National Park, Wyoming and Montana