Yellowstone is located in Northwestern Wyoming. With approximately 3 million visitors per year it is by far the most popular natural park in the United States.
Yellowstone National Park
Courtesy of Yahoo Maps Beta
Steamboat Geyser (Courtesy of USGS)
Yellowstone Hot Spring (USGS)
Fumaroles - Steam Vent (USGS)
Mud Pots (USGS)
The most famous thermal feature is Old Faithful, a geyser with a fairly regular eruption schedule, but there are also 10,000 other geysers, hot springs, mud pots, and fumaroles. With 10,000 thermal features, Yellowstone park contains 60% of the worlds total.
Yellowstone is fueled by a Hotspot. A hotspot is simply a location at the earths crust where magma from the mantle releases heat and in turn shapes the crust.
Artist Rendition of worldwide hot spots
The textbook example of a hot spot is the Hawaiian Island chain and the Emperor Seamount. The reason they are such good examples is that the Big Island of Hawaii is still erupting at a fairly consistent rate. More importantly you can see the past history of the hotspot, as an island chain, throughout the movement of the plate first towards the north and then west.
University of Illinois
Just like Hawaii, Yellowstone has a hotspot trail which has developed over many eruptions while the plates were in motion. The hotspot is more difficult to track than the Hawaiian Island chain but by using various dating techniques and carefully analyzing the surrounding rocks geologists have been able to identify several such hotspot eruptions over a period of approximately 17 million years.
The Yellowstone Hotspots are the result of approximately 17 eruptions. The most recent eruptions Lava Creek, Mesa Falls, and Huckleberry Ridge occurred approximately 600,000 years, 1.3 million years, and 2.1 million years ago respectively.
Each of the eruptions are the result of a super volcano. A super volcano is simply a volcano with a widespread effect. Super volcanoes often have devastating local effects and have the potential to devastate life abroad. One of the underlying differences between a regular volcano and a super volcano is the presence of silica rich, felsic, magma. The felsic magma is far more viscous than its mafic, silica poor, magma and this results in a violent eruption.
It is believed by many that the silica for the magma does not originate in the magma itself but is the result of granite inclusions in the melt. Granite being rich in silica plays an extremely important role in the viscosity of the magma and is by far the most influential aspect in determining the viscosity of the magma.
Silica Rich Rhyolite Canyon
(courtesy of USGS)
s you can see with two of the previous Yellowstone eruptions the ash has spread far further than a typical volcano, covering approximately 1/2 of the United States. An ash dispersion of this size is normal for a super volcano and will likely occur should Yellowstone erupt again. Some speculate that a future eruption could spread ash as far away as Europe within a few days.
The problem with an eruption of this size is that it only takes a few millimeters to destroy some crops and a few centimeters to destroy the rest.
Discovery Channel - Super Volcano ** Basic interactive
introduction to hotspots & Super Volcanoes
Official Yellowstone Website
United States Geological Survey (USGS)
Yellowstone's Restless Volcanic System
Types of Igneous Rock
Volcano Hazard Fact Sheet
Christiansen, The Quaternary and Pliocene Yellowstone Plateau Volcanic Field of Wyoming, Idaho, and Montana, California: USGS 2001
McGeary, David, Charles Plummer, and Diane Carlson. Physical Geology: Earth Revealed. New York: McGraw Hill, 2004.
Stanley, Steven M. Earth System History. W. H. Freeman and Company, 1999.
Link, P.K., M. A. Kuntz, and L B. PLatt. Regional Geology of Eastern Idaho and Western Wyoming. Colorado: The Geologic Society of America, 1992.
While this affects many of the surrounding residents and crops it is not the only problem a super eruption could cause. If Yellowstone were to erupt with the same fury as it had in the past, the amount of ash and sulfur thrown into the stratosphere would block the sun and could cool the planet by as much as 5 -15 degrees Celsius. In addition the sulfur would reside in the stratosphere for years, possibly decades, before it is cleared. While 5 appears minor it is more than enough to devastate the equatorial rainforests and possibly life as we know it when spread out of several years.