Volcano

Volcano ~ An opening in the Earth’s crust where hot gas, rocks

and magma erupt; they occur along plate boundaries.

Exciting, or Dangerous—Both?

VolcanoA 40, 000 km (24, 000 mi) horseshoe shaped area in the Pacific Ocean where tectonic plates meet. It is the home to 452 volcanoes (75% of the world’s volcanoes) and 90% of the world’s earthquakes.

Pacific Ring of Fire

Volcano

Classification:

1.Active2.Intermittent

3.Dormant4.Extinct

Volcano

Active~ Erupt constantly

(daily, weekly, monthly, yearly)

VolcanoKilauea, Hawaii

VolcanoArenal, Costa Rica

VolcanoGuatemala

VolcanoTvashtar, Jupiter

Largest Volcano in the Solar System

Olympus Mons, Mars

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Intermittent~ Erupt on a fairly regular basis

(every few years, or so)

VolcanoMt. St. Helens, Washington

Volcano

VolcanoMt. Vesuvius, Italy

Volcano

Volcano

Dormant~ Erupted a long time ago, have not in a while,

but could again.

VolcanoMt. Misti, Peru

VolcanoMt. Fuji, Japan

VolcanoMt. Lassen, California

VolcanoMt. Kilimanjaro, Africa

Volcano

Extinct~ Has not erupted for several years

(perhaps millions) and won’t anymore

VolcanoMt. Teranaki, New Zealand

VolcanoMt. Kenya, Africa

Volcano

Main Types

1.Cinder Cone2.Shield Cone

3.Composite Cone

Volcano

Cinder Cone~ Small volcanoes (less than 1000 feet tall) with

steep slopes made up of cinders

(hard bits of lava)Violent explosions/eruptions

VolcanoChile

VolcanoKilauea, Hawaii

VolcanoParicutin, Mexico

Volcano

Shield~ Large mountains (more than 10, 000 feet) with

gentle slopes made from lava in the cracks of the Earth.

Some of these volcanoes can reach over 25, 000 feet with much of the volcano under the

ocean (Mauna Loa, Hawaii).

VolcanoMauna Loa, Hawaii

VolcanoMauna Loa, Hawaii

VolcanoMauna Loa, Hawaii

Volcano

Composite~ Large mountains above sea level made up of

lava and rock bits (cinders )Violent eruptions and steep slopes.

VolcanoMt. Fuji, Japan

VolcanoMt. Vesuvius, Italy

VolcanoShishaldin, Alaska

VolcanoEruptions

~ What comes out of a volcano when it

erupts?

Volcano

Lava~ molten rock that will either ooze or flow quickly; the temperature usually is around

2, 000 degrees.The speed and shape of a lava flow depends on

the type of volcano and strength ofthe eruption.

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Ooze

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VolcanoFlow

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Pyroclastic Flow~ a fast moving current of hot gas, ash, and rock

traveling down the side of the volcano at speeds up to 200 mph with temperatures of

over 500 degrees Celsius.

VolcanoMayon, Philippines

Volcano

Volcano

VolcanoSt. Augustine, Alaska

Lahar

• A very hot, fast moving (cannot be outrun), and dangerous mix of melted snow, mud, and volcanic ash that results from volcanic steam or eruption.

Click to View

Volcano

Supervolcano~ a volcano that produces the largest eruptions

on Earth; can effect global climates for years.Typical eruptions happen several thousand

years apart.

Volcano

Yellowstone Park

Volcano

Each year, millions of visitors come to admire the hot springs and geysers of Yellowstone, the Nation’s first national park. Few are aware that these wonders are fueled by heat from a large reservoir of partially molten rock (magma), just a few miles beneath their feet. As this magma-which drives one of the world’s largest volcanic systems-rises, it pushes up the Earth’s crust beneath the Yellowstone Plateau

Volcano

Eruptions of the Yellowstone volcanic system have included the two largest volcanic eruptions in North America in the past few million years; the third largest was at Long Valley in California and produced the Bishop ash bed. The biggest of the Yellowstone eruptions occurred 2.1 million years ago, depositing the Huckleberry Ridge ash bed. These eruptions left behind huge volcanic depressions called “calderas” and spread volcanic ash over large parts of North America (see map). If another large caldera-forming eruption were to occur at Yellowstone, its effects would be worldwide. Thick ash deposits would bury vast areas of the United States, and injection of huge volumes of volcanic gases into the atmosphere could drastically affect global climate

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Supervolcanoes Around The World

Around the world there are several other volcanic areas that can be considered "supervolcanoes"- Long Valley in eastern California, Toba in Indonesia, and Taupo in New Zealand. Other "supervolcanoes" would likely include the large caldera volcanoes of Japan, and Indonesia.

Vent/Crater – an opening for the volcano

Lava – molten or melted rock.

Central Vent/Conduit – main chimney of the volcano

Magma Chamber – the “heart” of the volcano; gas, rock, and water mix here – pressure builds.

Ash Cloud – cinders, gas, and rock explode many miles into the air.

Side Vent – separate opening for lava to come out.

Asthenosphere-Layer below the lithosphere; made of molten rock

Cone – layers; made of rock from past eruptions

Volcano

Volcano