There is a nearly one-in-10 chance that a massive earthquake powerful enough to generate a mega-tsunami could occur in the Aleutian islands within the next five decades, according to a new study published last week in the Journal of Geophysical Research: Solid Earth.
According to lead researcher Rhett Butler, a geophysicist at the University of Hawaii at Mānoa School of Ocean and Earth Science and Technology (SOEST), and his colleagues, there is about a 9% chance that a Magnitude 9-plus earthquake will hit the Pacific island chain within the next 50 years, affecting an estimated 300,000 people living in the state of Hawai’i.
Earthquakes occur when two section of the planet’s rocky crust suddenly move past each other at a point known as the fault, and an earthquake occurring along the faults of the Aleutian Islands is likely to generate a tsunami capable of causing nearly $40 billion in damage in Hawaii, the study authors said Friday in a statement released by the university.
Researchers hope findings will serve as catalyst for mitigation efforts
“Necessity is the mother of invention,” explained Butler. “Having no recorded history of mega tsunamis in Hawai’i, and given the tsunami threat to Hawaii, we devised a model for Magnitude 9 earthquake rates following upon the insightful work of David Burbidge and others.”
His team developed a numerical model based on fault length and plate convergence rate, using Bayesian techniques of probability interpretation to account for uncertainties in their data. They then turned to historical records related to the five largest earthquakes ever (Kamchatka, 1952; Chile, 1960; Alaska, 1964; Sumatra-Andaman, 2004; and Tohoku, 2011) and geologic evidence of prehistoric seismic events preserved in costal sediments and other sites.
“We were surprised and pleased to see how well the model actually fit the paleotsunami data,” said Butler, adding that the recorded earthquake activities “differed in details,” but that each of those phenomena had “generated great tsunamis that caused enormous destruction.”
Based on their detailed analysis, the researchers believe that there is a 6.5% to 12% chance of a Magnitude 9 event occurring in the greater Aleutian islands within the next half-century, and that there is an annualized risk of nearly $30 million to the Hawaiian islands. The authors are hopeful that their findings will spur state officials to prioritize mitigation efforts to this potential disaster, and are now looking for ways to expand their analysis to smaller earthquakes.
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Image credit: Wikimedia Commons
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