Can earthquakes trigger volcano eruptions? Here's the science
By Robin George Andrews
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Even the ever-cautious says that sometimes, yes, earthquakes can trigger eruptions. The agency suggests that some historical examples imply that an earthquake’s severe ground shaking, or its ability to otherwise change the local pressure surrounding the magmatic source nearby, can trigger volcanic unrest. They cite the magnitude 7.2 earthquake on Hawaii’s Kilauea volcano on November 29, 1975, which was quickly followed by a short-lived eruption.
But there are problems. First, as the USGS stresses, the triggering mechanisms for such events are not well understood, and papers linking quakes to later eruptions can really only speculate.
Second, it’s possible that the timing in all these examples was just a coincidence. Geologists must understand the specific triggering and rule out chance before a connection can be definitively made–and Earth’s geological complexities make both extremely difficult.
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Statistical analyses are attempting to tackle the chance problem head-on. A 1998 Nature paper investigated whether magnitude 8.0 or larger quakes could trigger explosive volcanism up to 500 miles away from the epicenter within five days. Using data from the 16th century to the present, its authors found that these types of eruptions happened four times more often than chance alone could explain.
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[A research] team identified 30 volcanoes that may have at some point undergone a potentially triggered eruption. On a scale of days, the team found no evidence for triggering that couldn’t be explained by chance alone. That result actually goes against one of the findings of a 2006 review featuring Michael Manga, a coauthor on the new paper.
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