Thanks to its overly dramatic and rather persistent earthquake swarms, Yellowstone Caldera – America’s most infamous supervolcano – is getting all the attention lately, at least from the media. Volcanologists though are a little more concerned by what’s happening in Hawaii, and a new post by the United States Geological Survey (USGS) makes for some decidedly curious reading.
Technically speaking, Hawaii has been volcanically active since 1983, as lava has been continuously erupting from at least one vent – normally from Kilauea’s Puʻu ʻŌʻō vent – all this time. For the most part, those lava flows have fallen into the sea and haven’t bothered anyone at all. In fact, they’ve often put on quite the show.
However, along with the lava lake occasionally overflowing at Kilauea, volcanologists have noticed that the volcanic activity on Hawaii is higher than normal. In fact, back on September 17, 2015, the USGS raised the Volcano Alert Level – a form of geological caution labeling – from Green/Normal to Yellow/Advisory, meaning that people should be wary. Two years on, it’s still at that level.
Specifically, they are worried about Mauna Loa. This 700,000-year-old shield volcano is considered to be the largest single volcano (in terms of mass and volume) in the world and is one of the five major volcanoes that form the Island of Hawaii itself. Eruptions from this fiery mountain tend to be very fluid and non-explosive.
However, unlike plenty of volcanoes that erupt lava, Mauna Loa hasn’t done so since April 1984, which is an incredibly long time for an active volcano to remain quiet. Generally speaking, the longer a volcano remains silent for, the more explosive – or at least effusive – the next eruption will be.
It’s Mauna Loa's dormancy that has led to it being labeled one of the world’s “Decade Volcanoes,” which are for various reasons the most dangerous on Earth. The USGS, as you would expect, is keeping an eye on it. It appears that the rates of ground inflation and seismic activity have remained unnervingly above background levels for several years now.