A new paper out today in Nature offers some good news and bad news about volcanic eruptions. First, the bad news.
The researchers found that certain kinds of volcanoes can unleash a bunch of lava, then "recharge" with new magma from deep in the Earth within a matter of days or weeks. Previously, scientists believed it would take much longer for this recharging to happen. So one of these volcanoes could actually be simultaneously erupting and recharging its magma chamber with superheated rock from the Earth's mantle.
The good news is that this information could help us predict volcanic eruptions months in advance. By monitoring small earthquakes deep in the Earth's crust, where these rapid recharges are happening, seismologists might know when an eruption is coming. Usually, volcanic activity is monitored from the Earth's surface, where small and large quakes will signal that an eruption might be near — especially if the Earth is bulging over the top of the volcano. Now we know that some volcanoes might prepare for their eruptions deep underground, too.