A while back, I mentioned the awesome volcano that we call Yellowstone. Its last eruption spewed lava, rocks, and dust in an amount estimated at 2400 cubic kilometers. That’s 800 times more than Mt. Saint Helens put out, and it’s enough to pave its part-host state of Wyoming to a depth of about 10 meters, or 30-odd feet.
Since the discovery of past eruptions (and one now ‘overdue’?), geologists have been monitoring Yellowstone’s surface bulges, vast quantities of magma (liquid rock), and the rocks that hold it all in. How can they do that? They use records from earthquakes around the world that pass through, revealing the velocity of the seismic waves, which depends on rock and magma physical state.
Ninfa Bennington – from, where else, the Hawaii Volcano Observatory - and 7 of her colleagues also use the intricate distortions in the surface magnetic field. Be assured; there’s no imminent eruption, though the volumes of magma sitting or moving are stupendous – up to 10,000 cubic kilometers. Surprisingly, cooling and solidification of one rock type, rhyolitic, may enable the melted form of another type, basaltic, to fill in to take part in eruptions of basalt. At least these and other geologists are looking out for us.
This has been an outreach activity of the Las Cruces Academy, viewable at GreatSchools.org
Source: Nature, 2 Jan. 2025, pp. 97 ff.
Image: USGS
