| Title | For “smaller” Eruptions, Yellowstone Can Wake Up Quickly | |
| Date | Wednesday July 22 2015, @06:08AM | |
| Author | martyb | |
| Topic | ||
| from the someone-should-find-the-snooze-button dept. | ||
After someone learns about the massive, devastating eruptions that have been unleashed from the Yellowstone Caldera, their usual response is two-fold: Will that happen again? And how much warning would we get? In addition to those incredible events, however, Yellowstone and other calderas like it see smaller eruptions of lava much more frequently. These "small" eruptions are still about the size of the largest eruptions the world has seen in the last century—like Mount Pinatubo. So how much warning can we expect for them?
These eruptions spit up rhyolite lavas that are cooler but much more viscous—and therefore violent—than the familiar, chemically distinct, and comparatively tame Hawaiian volcanoes. Magmas vary in chemistry and evolve over time as minerals with lower melting points separate from others that are still solid. For stagnant magmas hovering around those melting points, a fresh shot of hot melt can sometimes stir the pot and cause an eruption. For many of the lava eruptions at Yellowstone, some of which have followed long periods of calm, that kind of rejuvenation is responsible.
...
Regardless, all this means that it didn't take Yellowstone long at all to wake up. Prior to this eruption, Yellowstone had been quiet for 220,000 years. But just a handful of months or years after fresh magma stirred things up, it burped up 2 to 3 cubic kilometers of lava.Odds are good that this will be the type of eruption that occurs next at Yellowstone rather than the rarer "super-eruptions" that inspire Discovery Channel animations. "Fortunately," the researchers write, "any significant rejuvenation of the reservoir is likely to be associated with deformation or seismicity and identifiable by geophysical monitoring." So we should have a useful amount of warning that something angry is brewing down in Yellowstone's volcanic guts. Just not as much warning as we might like.
A super eruption at Yellowstone is a popular doomsday scenario.
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printed from SoylentNews, For “smaller” Eruptions, Yellowstone Can Wake Up Quickly on 2024-05-16 23:04:18