Janice Shiu - 2020 - 12.307
The Yellowstone Caldera has erupted multiple times in its existence, with each eruption covering great portions of North America with ash (Figure 1) (USGS, 2014). Given that it has been nearly 640,000 years since the last major Yellowstone eruption, which occurs at a 600,000 - 800,000 year cycle, There is a possibility that Yellowstone will erupt soon in geologic time (USGS, 2014).
Figure 1: Known ashbed cover from major Yelowstone eruptions shaded in brown with white dashed borders (USGS, 2014)
For humans, a Yellowstone eruption can be catastrophic, from displacement of people throughout the United States to global changes in climate. This experiment models the spread of material over 10 days if the Yellowstone erupted on February 21, 2017. Modifying Professor Glenn Flierl's program for tracing and interpolating atmospheric particle positions using wind data, 11 particles were released in a diagonal transect of Yellowstone National Park between 1000-200 hPa with 100 hPa resolution. Each particle underwent 3 hour time steps to move to its next position.
a. | b. | c. |
|---|---|---|
d. | e. | f. |
g. | h. | i. |
Figures 2a-i: Predicted trajectory of particles released in Yellowstone eruption over 10 days after February 21, 2017
There are limitations to these predictions. This model assumes lightweight particles that do not change in elevation over time. As the model does not account for particle size and density or weather phenomena, such as rain, that would result in material changing levels or deposits. Eruptions typically contain a great variety of materials, such as pyroclastic flows, fine ash, and gaseous materials that could significantly affect global climate. Each of these materials will have different distributions throughout the eruption plume – lighter materials may go to higher levels with greater horizontal spread while heavier materials will eject to lower altitudes. Additionally, rains, gravity, and vertical winds not factored into the model will eventually remove these materials from the atmosphere. Consequently, different materials will experience different travel times and initial spread from the eruption, which, as seen in Figures 2a-i, can greatly affect how and where material will travel.
Future expansions of this project may include investigations of potential eruption materials, plume dynamics, material residence time, and the relevant effects of an explosion to human activity.
References:
Modeling the Ash Distribution of a Yellowstone Supereruption (2014). (2014, August 27). Retrieved from https://volcanoes.usgs.gov/volcanoes/yellowstone/yellowstone_sub_page_91.html