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?. Volcano. Pacific Ring of Fire.
~ An opening in the Earth’s crust where hot gas, rocks and magma erupt; they occur along plate boundaries.
Pacific Ring of Fire
A 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.
~ Erupt constantly
(daily, weekly, monthly, yearly)
Arenal, Costa Rica
Olympus Mons, Mars
~ Erupt on a fairly regular basis
(every few years, or so)
Mt. St. Helens, Washington
~ Erupted a long time ago, have not in a while, but could again.
Mt. Misti, Peru
Mt. Lassen, California
Mt. Kilimanjaro, Africa
~ Has not erupted for several years
(perhaps millions) and won’t anymore
Mt. Teranaki, New Zealand
Mt. Kenya, Africa
~ Small volcanoes (less than 1000 feet tall) with steep slopes made up of
(hard bits of lava)
~ 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).
~ Large mountains above sea level made up of lava and rock bits (cinders )
Violent eruptions and steep slopes.
~ What comes out of a volcano when it erupts?
~ 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 of
~ 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.
St. Augustine, Alaska
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~ a volcano that produces the largest eruptions on Earth; can effect global climates for years.
Typical eruptions happen several thousand years apart.
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
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
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
Side Vent – separate opening for lava to come out.
Lava – molten or melted rock.
Central Vent/Conduit – main chimney of the volcano
Cone – layers; made of rock from past eruptions
Magma Chamber – the “heart” of the volcano; gas, rock, and water mix here – pressure builds.