When it rains it pours...or blows lava?
After studying the 2018 eruption of Kīlauea volcano in Hawaii, scientists suggest it was the rainfall pattern that contributed to its eruption.
In a new study, published in the journal Nature, scientists at the University of Miami showed that the eruption was likely started by prolonged, and at times extreme, rainfall in the months leading up to the event.
“We knew that changes in the water content in the Earth’s subsurface can trigger earthquakes and landslides. Now we know that it can also trigger volcanic eruptions,” said Falk Amelung, professor of geophysics at the UM Rosenstiel School and coauthor of the study. “Under pressure from magma, wet rock breaks easier than dry rock. It is as simple as that.”
On May 3, 2018, Kilauea shot lava nearly two hundred feet in the air and over 13 square miles across the well-populated east coast of Hawaii’s Big Island.
Researchers modeled the pressure buildup within the volcano and discovered it was at its highest in almost half a century immediately prior to the eruption.
“An eruption happens when the pressure in the magma chamber is high enough to break the surrounding rock and the magma travels to the surface,” said researcher Falk Amelung. “This pressurization causes inflation of the ground by tens of centimeters. As we did not see any significant inflation in the year prior to the eruption we started to think about alternative explanations.”
While small steam explosions and volcanic earthquakes have been linked to rainfall infiltration at other volcanoes in the past, this is the first time that this mechanism has been invoked to explain deeper magmatic processes.
The authors highlight that if this process can be detected at Kīlauea, then it is likely to occur elsewhere as well and may be a useful marker for predicting eruptions.