How are volcanoes formed?
- To summarize(sort of) this video, Volcanoes form when magma from the Earth pushes upward which forms a hill like shape and the volcano becomes bigger as it continues to erupt. The power of volcanoes are measured in the Volcanic Explosivity Index. The weakest is 1 (gentle) and the strongest is 8 (mega-colossal). The volcano that caused Pompeii to be buried in 4-6 meters of ash, was only 5 (cataclysmic) on the Index. Whenever a volcano erupts, some of the ash gets tossed into the atmosphere and causes the Earth’s temperature to decrease and this can have a huge impact to thing like agriculture.1816 is called “The Year Without A Summer”. This was cause by a volcano in Indonesia named Mt.Tambora in April 1815 and cause the entire Earth to plummet into a year long winter. The volcano was 7 (Super-colossal) on the index. This caused crop and livestock to die all over the world and the area around the volcano was buried by ash. While this was 7 on the index, 8 is far worse. About 100x more ash was pumped up into the atmosphere and can cause all of Argentina to be buried by 1 meter of ash. This causes the Earth to plummet into a decade (10 years) long winter. These volcanic eruptions happened millions of years ago and the closest one happened about 800000 years ago. This caused early humans to die off to a global population of ~3000.
This is a picture of Mt. St. Helens, one of the biggest volcanoes in the U.S.A.
When it erupted in 1980, It was the most disastrous volcano eruption in American history.
Today, it is rated as the 2nd biggest volcano threat in the U.S.A. It is also one of the most active and is near major metropolitan centers.
Credits:
Created with images by skeeze - "volcano lava flowing" • skeeze - "volcano lava flowing"