July 26, 2012 - The United States “Killer” Volcano: The Yellowstone Caldera is located in Yellowstone National Park in the United States. The major features of the caldera measure 55 kilometers (34 mi) by 72 kilometers (45 mi). After a BBC television science program coined the term super volcano in 2000, it has often been referred to as the Yellowstone Super volcano. Yellowstone, like Hawaii, is believed to lie on top of an area called a hotspot where light, hot, molten mantle rock rises towards the surface. It created the eastern Snake River Plain (to the west of Yellowstone – pictured below) through a series of huge volcanic eruptions.
Over the past 17 million years, this hotspot has generated a succession of violent eruptions and less violent floods of basaltic lava. Together these eruptions have helped create the eastern part of the Snake River Plain from a once-mountainous region. At least a dozen or so of these eruptions were so massive that they are classified as super eruptions. Volcanic eruptions sometimes empty their stores of magma so swiftly that they cause the overlying land to collapse into the emptied magma chamber, forming a geographic depression called a caldera. Calderas formed from explosive super eruptions can be as wide and deep as mid- to large-sized lakes and can be responsible for destroying broad swaths of mountain ranges.
The loosely defined term “super volcano” has been used to describe volcanic fields that produce exceptionally large volcanic eruptions. The three super eruptions occurred 2.1 million, 1.3 million, and 640,000 years ago. The Henry’s Fork Caldera (1.2 million years ago) produced the smaller Mesa Falls Tuff but is the only caldera from the SRP-Y hotspot that is plainly visible today. Pictured below, Upper Mesa Falls, Henrys Fork of the Snake River, Idaho.
Currently, volcanic activity is exhibited via numerous geothermal vents scattered throughout the region, including the famous Old Faithful Geyser. Geologists were alarmed when the Old Faithful Geyser, suddenly became less faithful, in terms of its periodic eruption cycle. Could the Yellowstone Caldera be getting ready for another Super Eruption? If so, it would wipe-out the United States as we know it; and much of the world!
The Master of Disaster