What are Evidences of Volcanic Activity beneath Yellowstone?
Hydrothermal Activity
“The hydrothermal phenomena", states Rosi et al.,(1999), "are kept active by the high temperature of the rocks and infiltration of water” (p. 239). Volcanoes give off large quantities of gas and the fluids brought to the surface by hot springs can result from the degassing of magma deep in the Earth or from the warming of subterranean water by the magma’s heat (Rosi, et al.,1999). In the case of aquifiers heated by magma that are not sealed off by impermeable covers, the heated water will rise to the surface and create various kinds of thermal events. The most spectacular of these are geysers: jets of boiling water, steam, and gas that periodically burst from the depths of the Earth (Kevin, 2012).
MudpotsThe bubbles that burst make funny and rude noises. They are usually gray in color, or can be orange and red tinted by iron and metals from the earth (NPS, 2013). Video by Phillips, (2011).
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Noisy plopping.Mudpots have a limited water supply. Microorganisms use the gas from under the earth to help chemicals break down rock into a thick, wet clay. Bubbles form and pop as heat and gas rise from below (NPS, 2013).
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Earthquakes
There are two main reasons why Yellowstone experiences earthquakes everyday. The heat from volcanic activity millions of years ago stretched out the North American Plate beneath Yellowstone. This produced the Teton fault that runs north to south on the eastern front of the Teton Range. The surface where two blocks of earth slip past one another is called a fault (USGS, 2012). Earthquakes are caused when the rocks along a fault push against one another and suddenly break due to pressure. The release of pressure causes the ground to shake producing seismic waves (USGS, 2012). The pressure from the remaining magma chamber causes the earth to expand and quake which affects the hydrothermal plumbing under the park (Kevin, 2012).
The area is also located in the Intermountain Seismic Belt that runs north-south from Montana to Arizona (YPF, 2012). The tectonic quakes occur because of the combination of the active volcano under Yellowstone and the ISBelt. The average number of earthquakes is about 1,600 per year (YPF, 2012). The YELLOWSTONE VOLCANO OBSERVATORY posts a monthly update of the earthquakes that occur in the Yellowstone National Park region. Currently (as of April, 2013) the earthquake activity remains at a low level, even though there are hundreds of earthquakes each month with varying magnitudes.
The area is also located in the Intermountain Seismic Belt that runs north-south from Montana to Arizona (YPF, 2012). The tectonic quakes occur because of the combination of the active volcano under Yellowstone and the ISBelt. The average number of earthquakes is about 1,600 per year (YPF, 2012). The YELLOWSTONE VOLCANO OBSERVATORY posts a monthly update of the earthquakes that occur in the Yellowstone National Park region. Currently (as of April, 2013) the earthquake activity remains at a low level, even though there are hundreds of earthquakes each month with varying magnitudes.