Yellowstone volcano’s last major eruption took place an estimated 640,000 years ago when it formed the volcanic caldera visited by millions today. Since then, the supervolcano erupted around 80 times, spewing molten rock, volcanic ash and smoke. Yellowstone experts estimate the supervolcano erupts anywhere between 600,000 to 700,000 years. This has led some to fear the Yellowstone system is overdue another major volcanic blast in the near future.
Thankfully, scientists studying past supervolcano eruptions around the globe, believe Yellowstone will rumble long before it roars back to life.
A study led by volcano researchers from the University of Illinois (UI), US, has found supervolcano eruptions are preceded by years of significant seismic activity.
A volcano like Yellowstone could take tens if not hundreds of thousands of years worth of warning signals before it pops.
Patricia Gregg, geology professor at UI, explained: “When new magma starts to rejuvenate a supervolcano system, we can expect to see massive uplift, faulting and earthquake activity.
Yellowstone volcano: Powerful seismic activity will precede an imminent eruption years in advance
“Far greater than the meter-scale events we have seen in recent time. We are talking on the range of tens to hundreds of meters of uplift.
“Even then, our models predict that the system would inflate for hundreds to thousands of years before we witness catastrophic eruption.”
Supervolcanoes like Yellowstone do not act and erupt in the same manner as smaller volcanoes like Etna do.
Typically, a volcano is thought to erupt when the buildup of pressure caused by the swelling of magma, bursts through the volcano’s rocky dome.
Supervolcanoes, however, tend to be active in areas subjected to “significant tectonic stress”.
Thousands of years before we witness catastrophic eruption
These are parts of the world where tectonic plates are in constant motion, rubbing against one another and pulling apart.
Tectonic motions will have an impact on how models predict supervolcano behaviour.
Fellow researcher and graduate student Haley Cabaniss said: “It does not matter if it is extensional, compressional or shear stress.
“Any tectonic stress will help destabilise rock and trigger eruptions, just on slightly different timescales.
“The remarkable thing we found is that the timing seems to depend not only on tectonic stress, but also on whether magma is being actively supplied to the volcano.”
Supervolcanoes can lay dormant for incredibly long periods of time – much longer than humanity has been around for.
According to professor Gregg, this can extend into millions of years at a time.
Yellowstone volcano: The supervolcano system last erupted 640,000 years ago
Yellowstone volcano: Experts predict thousands of years of warning signs before imminent eruption
The volcano expert said: “In other words, they may remain stable, doing almost nothing for 999,000 years, then start a period of rejuvenation leading to a large-scale eruption.”
Whatever the case may be, Yellowstone is one of the world’s best-monitored volcano systems.
Ms Cabaniss said: “It is also important to note that our research suggests that the whole rejuvenation-to-eruption process will take place over several or more human lifetimes.
“Our models indicate that there should be plenty of warning.”
Daily Express :: Science Feed