
Mount St. Helens 2005
1.Biggest Volcano
The biggest volcano in our solar system is on Mars. Olympus Mons is 600 km (373 miles) wide and 21 km (13 miles) tall.
2.Most Explosive
Volcanoes are measured by the Volcano Explosivity Index.
VEI | Ejecta volume | Classification | Description | Plume | Frequency | Examples |
---|---|---|---|---|---|---|
0 | < 10,000 m³ | Hawaiian | non-explosive | < 100 m | constant | Kilauea |
1 | > 10,000 m³ | Hawaiian / Strombolian | gentle | 100–1000 m | daily | Stromboli |
2 | > 1,000,000 m³ | Strombolian / Vulcanian | explosive | 1–5 km | weekly | StromboliGaleras, 1992 |
3 | > 10,000,000 m³ | Vulcanian / Peléan | severe | 3–15 km | few months | Ruiz, 1985 |
4 | > 0.1 km³ | Peléan / Plinian | cataclysmic | 10–25 km | ≥ 1 yr | Pelée (1902), Eyjafjallajökull (2010) |
5 | > 1 km³ | Plinian | paroxysmic | 20–35 km | ≥ 10 yrs | Vesuvius (79) St. Helens (1980) |
6 | > 10 km³ | Plinian / Ultra-Plinian | colossal | > 30 km | ≥ 100 yrs | Pinatubo (1991) |
7 | > 100 km³ | Ultra-Plinian | mega-colossal | > 40 km | ≥ 1,000 yrs | Tambora (1815) |
8 | > 1,000 km³ | Supervolcanic | apocalyptic | > 50 km | ≥ 10,000 yrs | Yellowstone (640,000 BC) |
3. Largest Eruptions
Five Largest Volcanic Eruptions in Recent History
Volcano |
Location | When | Volcanic Explosivity Index (VEI) |
Tambora | Sunda Islands, Indonesia |
April 10, 1815 | 7 |
Krakatoa | Indonesian island of Krakatoa |
Aug. 27, 1883 | 6 |
Novarupta | Alaska Peninsula | June 6, 1912 | 6 |
Pinatubo | Philippines | June 15, 1991 | 6 |
Santa Maria | Pacific coast of Guatemala |
Oct. 24, 1902 | 6 |
4. Locations
Volcanoes may be found on the ocean floor and under the icecaps.
5. Eruptions
Volcanic eruptions can send ash over 30 km (17 miles) into the atmosphere.
6. Effects of Eruptions
Erupting volcanoes can trigger tsunamis, flash floods, earthquakes, mud flows, and rock falls.
7. Locations on Earth
More than half of the 500 active volcanoes found on Earth are in a circle around the Pacific Ocean known as the “Ring of Fire.” The United States has active volcanoes in Hawaii, Alaska, California, Oregon, and Washington.
8. Active, Dormant, and Extinct Volcanoes
Volcanoes can be active, dormant, or extinct. Active means the volcano has had an eruption in the last few thousand years. Dormant means the volcano has the potential to erupt although it hasn’t erupted recently. Extinct means the volcano is not likely to erupt again.
9. Deadliest
The deadliest eruption in what is now the United States took place 200 years ago. Kilauea erupted on the Hawaiian Islands killing more than 400 people.
10.Types of Volcanoes
There are different kinds of volcanoes.
When the lava contains less gas, the eruption is gentler. Flow after flow of thin streams of lava flows out in all directions from the volcano’s vent. This creates a flat, dome-shaped mountain with broad slopes.
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Lava domes are formed by small spherical masses of lava. These are too thick to flow. The lava piles around the vent. Lava domes often grow larger by expansion within the volcano. |
![]() Composite or strata volcanoes contain a lot of gas mixed in with the lava. Because of the built-up gas, the eruptions are violent. The volcano spews out gases, ash, and hot lava. The lava doesn’t travel far. It piles up creating a volcano that is built of many layers of ash and solidified lava.
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![]() Cinder cones are formed when a volcano violently erupts. The lava quickly congeals and falls around the vent in a circular shape.
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Information Sources
Photo Mount St.Helens
http://commons.wikimedia.org/wiki/File:Mt_St_Helens_Eruption_March_8,_2005.jpg
Fun Volcano Facts
http://www.sciencekids.co.nz/sciencefacts/earth/volcano.html
11 Facts About Volcanoes
https://www.dosomething.org/facts/11-facts-about-volcanoes
Volcanic Explosivity Index
Five Biggest Volcano Eruptions in Recent History
http://www.csmonitor.com/Science/2010/0418/Five-biggest-volcano-eruptions-in-recent-history
50 Amazing Volcano Facts
http://www.livescience.com/31774-amazing-volcano-facts.html
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