Yellowstone Magma Reservoir: Twice the Hotspot than Previously Believed

Source: http://www.nature.com/news/large-magma-reservoir-gets-bigger-1.14036 Be of good cheer: this will not mean that Yellowstone is twice as likely to cataclysmically erupt as a mega volcano (or that it will become next month’s big premiere movie on SyFy, for that matter).  However, it does mean that the chances of a massive earthquake in the area are much larger than originally thought. Yellowstone National Park attracts millions of visitors each year, drawn as much to the spectacle of its geysers and hot springs as they are to the park’s overall majestic scenery.  The tremendous heat needed for geysers such as Old Faithful and the Castle Geyser is provided by the massive magma chamber upon which Yellowstone sits.  It is this magma reservoir which has been responsible for at least three massive eruptions of epic scale in the past two million years. And now, because of research just announced by a team of geological scientists at the University of Utah, we can rest easy knowing that Yellowstone’s hotspot is at least two times larger than it was originally thought to be.  Disaster-genre screenwriters, take note! At 80 kilometers long, 20 kilometers wide and with a volume of 8,000 cubic kilometers, the Yellowstone reservoir is being called the biggest such chamber imaged thus far.  During a presentation on October 27^th at the annual meeting of the Geological Society of America, University of Utah researchers Jamie Farrell and Robert Smith revealed their findings: the result of analysis of more than 4,500 earthquakes in the Yellowstone vicinity and beyond.  By studying the waves generated by these quakes and their speed through the region, Farrell and Smith were able to accurately map the size and shape of the hotspot beneath Yellowstone’s caldera.  They discovered that Yellowstone’s mammoth magma chamber is twice as large and roomy than previously believed; and that at any given time six to eight percent of this chamber – which is being likened more to a sponge than to a continuous cavity – is flooded with molten rock, flowing from deep within the Earth’s mantle. However, this does not mean that Yellowstone is at double the risk of erupting into ash and flames of biblical proportions.  The biggest concern is earthquakes: something that Yellowstone is rife with.  Quakes much more faint than humanly perceivable occur every day at Yellowstone, sometimes even every few seconds.  It is the natural consequence of the Earth “letting off steam” at the site of Yellowstone.  It is the larger events – those such as the 1959 earthquake at Lake Hebgen that measured 7.3 and was responsible for 29 deaths – that concern geological scientists, because the odds of such an occurrence are now drastically higher. This will likely be no deterrence for the multitudes of people who flock to enjoy the natural wonders of Yellowstone, or for the millions of people who have been longtime residents in the region around the park.  Fortunately for all, occurrences of truly life-altering earthquakes are few and far between.