Researchers from the U.S. Geological Survey have created a model showing how a super eruption at the Yellowstone National Park will affect nearby cities.
The computer showed that a supposed and massive eruption will form a big cloud of ash that will spread out across North America. The model, dubbed the Ash3D, uses wind patterns to calculate how far the ash will travel. The last super eruption of Yellowstone occurred 640,000 years ago.
The model showed that the eruption will create a meter-thick ash layer in all cities in close proximity to the Yellowstone volcano. In the Midwest, a few centimeters of ash is projected to be plummeted while coastal cities will have a few millimeter of ash buildup.
Ash3D helped the researchers understand how the previous eruptions created a widespread distribution of ash in places in the park's periphery. Aside from probing ash-distribution patterns, the Ash3D can also be used to identify potential hazards that volcanoes in Alaska may bring.
"In essence, the eruption makes its own winds that can overcome the prevailing westerlies, which normally dominate weather patterns in the United States," explained Larry Mastin, a geologist at the USGS Cascades Volcano Observatory in Vancouver, Wash., and the lead author of the research paper.
The computer model also presented the variations between the ash distribution of small eruptions and super eruptions. Ash3D revealed that smaller eruptions produce faster ash distribution which resembles a fan when seen from a higher ground. On the other hand, a super eruption's ash distribution can result to a bull's eye-like pattern; the ash accrues in the middle and falls as they travel far from the center of the eruption.
A super eruption is considered the strongest kind of eruption and can expel as much as 1,000 cubic kilometers of ash and lava.
Further findings of this study were published in the Oct.1 issue of Geochemistry, Geophysics, Geosystems.