A. What is a volcano?

• An area of the Earth’s surface through which magma and volcanic gases pass.

• 2. Most are located at plate boundaries.

• 3. 75% of the volcanoes in the world are located in the Ring of Fire.

3 Types of Volcanoes

• 1. Shield Volcano

• 2. Cinder Cone Volcano

• 3. Composite Volcano

Shield Volcano• 1. Produced by:• a. layers of lava released from non-

explosive eruptions.– b. lava spreads out over a wide area.

• 2. These volcanoes have:• a. gently sloping sides.• b. lava spreads out over a wide area.• 3. Shaped like a shield• Mount Kea, in Hawaii, is the largest volcano on Earth.• Measured from its base on the sea-floor, it is taller than

mount Everest.

Shield Volcano

• Here are 4 of the volcanoes that comprise the big island of Hawai'i. They are Mauna Kea (MK), Mauna Loa (ML), Hualalai (H), and Kohala (K). The photo was taken from near the summit of East Maui volcano (EM). These are the largest volcanoes on Earth.

Shield Volcano

Belknap Shield Volcano in Oregon.

Cinder Cone Volcano

1. Produced from: a. moderately explosive eruptions. b.

pyroclastic material (hardened blobs of magma, small pieces of hardened magma and ash)

2. Cinder cone volcanoes:a. have steep slopes.b. are usually small.c. often occur in clusters.

d. rode very quickly, pyroclastic material is not cemented together.

Cinder Cone Volcano

Veniaminof, Alaska Mount Etna, Italy

Composite Volcanoes

• 1. Composite Volcanoes• a. form from alternating explosive and

non-explosive eruptions.

• b. broad bases and sides that get steeper toward the top.

• c. most common

• d. called strato-volcanoes (layers)

Composite Volcanoes

Mount Ranier, Washington

Costa Rica- Arenal Volcano

•http://www.arenal.net/arenal-volcano.htm

What is a crater?

1.The area around the central vent of a volcano is called a crater.

What is a Hotspot?1. an area of persistent volcanic

activity.

2. originate at unusually hot areas of the mantle-core boundary.

3. Overlying mantle melts forming plumes of magma that rise and penetrate the crust forming volcanoes.

4. Hawaii, Iceland, and Yellowstone are examples of hot spots.