Yellowstone Supervolcano Eruptions More Massive Than Thought

 

The geysers and hotspots which are the main features of America's Yellowstone Park are merely what is left of massive volcanic eruptions that occurred in the area millions of years ago. British researchers have used new techniques  to identify where the eruptions took place and how strong they were.

Scientists now know that the whole northwestern region of the United States was hit by gigantic eruptions. They say that there were at least a dozen eruptions in the area over the last 12 million years, some of which were much stronger than previously thought.

The last Yellowstone supervolcano outburst occurred 640 000 years ago. The last flow of lava took place 70000 years ago. The new study suggests that a further gigantic eruption, about 2000 times as strong as the Mount St. Helen outburst in 1981,  may take place within the next few thousand years. Scientists have discovered a massive new magma chamber under Yellowstone. The next eruption would release thousands of cubic kilometres of material into the atmosphere, covering the whole North American continent in ash.

 

The Yellowstone supervolcano is one of a series of volcanoes that spread from Oregon eastward across the Snake River Valley and the northwestern US. Geologists now think that this moving hotspot may have run into a thicker geologic plate , needing more energy for an eruption to occur.

 

Yellowstone Caldera

Part of the Yellowstone caldera, which was formed in the last volcanic eruption

 

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Words

  • atmosphere = the mixture of gases that are around the earth
  • ash = soft grey or black powder that is left after something has burned
  • caldera = large hole that is formed when the top of a volcano collapses after an eruption; often filled with a lake
  • chamber = room, area
  • discover = to find out for the first time
  • dozen = 12
  • eruption = when flames, rock and gas come out of a volcano
  • feature = important part of an area
  • flow = move down a mountain slowly
  • geologic plate = one of the moving parts of the earth's surface
  • geologist = person who studies the rocks that make up the earth's surface
  • geyser = hole in the ground from which hot water and steam come up
  • hotspot = place with volcanic activity and earthquakes
  • identify = find out
  • magma = hot liquid rock below the surface of the earth
  • massive = great
  • merely = only
  • occur = happen
  • outburst = eruption
  • previously = earlier
  • release = set free
  • researcher = person who studies things closely in order to find out more about them
  • scientist = person who is trained in science and works in a lab
  • spread = move from one place to another
  • suggest = here: to say that something may have been possible
  • technique = method