The internet is both a blessing and a curse. It provides us with endless information on any topic you could dream of at just the click of a button. On the flip side, it’s full of crap that’s easy to believe if you don’t spend the time looking for credible sources to back up what is being said. One such example is the Yellowstone supervolcano. Rumors often surface that it is about to erupt, and they’re doing the rounds once again. So, what’s the crack with this colossal caldera? Is it about to shoot its load and wipe out millions of people? Let’s take a look.
Yellowstone National Park is home to a huge caldera (bowl-shaped feature that resulted from the collapse of land after a volcanic eruption) and supervolcano that are collectively known as the Yellowstone Caldera. A recent study discovered that the volcano has a gargantuan magma chamber measuring 90 km in length and up to 17 km in depth in some areas, which was more than double previous estimates. However, according to experts, the updated size does not increase the volcanic hazard in the Yellowstone region.
Scientists believe that three super-eruptions have occurred in the past on a 600,000-700,000 year cycle, starting around 2.1 million years ago. The last huge eruption is thought to have occurred around 640,000 years ago, but that doesn’t necessarily mean we’re in the firing line right now. At the same time, scientists are very aware of the implications of such an eruption. Consequently, the US Geological Survey (USGS) Volcanic Hazards Program keeps a watchful eye on this beast and is constantly recording its activity via seismometers and other bits of monitoring equipment.
It is not a quiet volcano- hot fluids are constantly yo-yoing through the crust, resulting in frequent earthquakes. Indeed, just last month 99 earthquakes were recorded by the USGS in the Yellowstone National Park region, the largest of which was a magnitude 2.5. Furthermore, 50% of these occurred in just two consecutive days. This may sound like a lot, but it’s common for this region and the activity was not outside of normal background levels. If an eruption was on its way, hundreds or even thousands of earthquakes would be triggered as the magma forces its way through the crust. It wouldn’t go unnoticed, so until the USGS tell us that this is happening, you can be fairly certain that rumors of an imminent blow are just that-rumors, nothing more.
Scientists also believe that if an eruption were to take place in the not-so-distant future, it would probably be (relatively) small, maybe on a Mount St Helens scale, rather than a super eruption that is going to wipe out large numbers of people.
A few months back, many people got their knickers in a twist about a video supposedly showing bison fleeing the park. Some believed that this meant that the volcano was about to blow because it coincided with a magnitude 4.7 earthquake, but that was not the case. The animals leave the park during winter to migrate to lower elevations where food resources are more likely to be abundant. Furthermore, the video was recorded some weeks before the big quake.
In sum- experts are watching this supervolcano like a hawk and they produce monthly updates on it for us all to see. If something out of the ordinary was going on, the USGS would tell us. If eruption warnings or scares start floating around the internet, check the source, because if it’s not from the USGS or another credible organization then it’s probably not true.
[Header image “Grand Prismatic Spring and runoff,” by Scorpions and Centaurs, via Flickr, used in accordance with CC BY-NC-SA 2.0]
Wonder Of Science