There have been reports in the media that a couple of supervolcanoes, such as Yellowstone in the US and Taupo in New Zealand, that are saying are on the verge of eruption.
The United State Geological Survey (USGS) says, however, that such an eruption at Yellowstone is very unlikely in the next thousand or even 10,000 years. Scientists say they have also found no indication of an imminent smaller eruption of lava.
New Zealand’s GeoNet website that provides geological hazard information for New Zealand indicates that the alert level for a Taupo eruption is currently at 0 and that there is no volcanic unrest.
Comparison of volumes of magma erupted from selected volcanoes within the last 2 million years. (USGS)
A new study led by researchers at the University of Illinois at Urbana-Champaign provides some comfort, suggesting that geological signs indicating a catastrophic eruption would be clear far in advance.
While there have been reports of seismic or geyser activity near a couple of supervolcanoes, the study, published in journal Geophysical Letters suggests that signs of disastrous eruption will be much greater and longer-lasting than anything that has been documented so far.
A supervolcano is defined as a volcano that at one time erupted with a force of magnitude 8 on the Volcano Explosivity Index (VEI), which means it erupted more than 1,000 cubic kilometers of material.
The US Geological Survey (USGS) says such an eruption would not only have a cataclysmic impact on a large part of the area closest to the volcano but would also affect global weather patterns, which would seriously influence human activity, for many years after.
The Yellowstone supervolcano has erupted at least three times in the past – 640,000 years ago (VEI 8 – Lava Creek), 1.2 million years ago (VEI 7 – Mesa Falls) and its largest (VEI 8 – Huckleberry Ridge) 2.1 million years ago.
Illustration of what the Toba eruption might have looked like around 42 km above northern Sumatra. (Wikimedia Commons Creative Commons Attribution-Share Alike 4.0 International, 3.0 Unported, 2.5 Generic, 2.0 Generic and 1.0 Generic licenses)
New Zealand’s Taupo supervolcano has erupted twice in relatively recent times.
The first, a VEI 8 eruption called the Oruanui, took place about 26,500 years ago.
The more recent, VEI 7 Taupo or Hatepe eruption happened only 1,800 years ago and is said to be one of the most violent volcanic eruptions over the last 5,000 years.
But, scientists say the Toba supervolcanic eruption, which took place some 74,000-75,000 years ago in an area that is now home to Lake Toba in Sumatra, Indonesia was one the largest known VEI 8 volcanic eruptions ever to take place on Earth.
It’s said that the Toba supervolcano spewed some 2,800 cubic kilometers of material.
Of course,since an Eruption of this proportion hasn’t happened in 1800 yrs.No one really knows what they look like.All this ‘science’ is best guess based on what the Geology tells the scientist.So I put out there,all the advanced warning may already be going on and has been so long that we think it ‘normal’.How can anyone be sure that Yellowstone was having 1000s of earthquakes a year a couple hundred years ago like it does now?