Hawaii Is At Risk Of A Mega-Tsunami


Jonathan O'Callaghan

Senior Staff Writer

416 Hawaii Is At Risk Of A Mega-Tsunami
A view of Kauai Island, the northernmost of the Hawaiian islands. Alexander Demyanenko/Shutterstock

A somewhat unnerving study has suggested there is a small – but significant – chance that an earthquake and resulting tsunami could devastate Hawaii in the next 50 years.

Published in the Journal of Geophysical Research, the study from the University of Hawaii at Mānoa (UHM) says there is approximately a 9 percent chance of a magnitude 9 or greater earthquake hitting the Aleutian Islands (which extend west from Alaska) in the next half a century, producing a mega-tsunami that could engulf Hawaii. 


A previous report suggested that a large tsunami would put more than 200,000 residents of Hawaii at risk, and cause $40 billion worth of damage. If the scenario described above did play out, people on the Hawaiian islands would have about 4 hours to get to safe higher ground before the tsunami struck.

This latest study is not based on any recent activity in the Aleutian Islands, though. It is instead a numerical model based on the global rate of large earthquakes, combined with previous activity reported in the Aleutian Islands’ subduction zone, where one of Earth’s tectonic plates passes under another, known as a fault. 

The model also incorporated previous tsunamis caused by earthquakes, such as the one that hit Japan in 2011.

“These are rare events,” lead author Rhett Butler told Hawaii News Now. “They don't happen all the time but there is a chance for them and our effort here is to try to define what that chance might be.”


In 2014, Butler and his team found a pile of marine debris in a giant sinkhole that they think is evidence of a huge tsunami 9 meters (30 feet) high hitting Hawaii half a millennium ago. They believe this was triggered by a magnitude 9 earthquake from the Aleutian Islands. Now, they think there is a risk of another one.

The team stress that they aren’t trying to cause alarm, but rather they are hoping to alert people who might be affected. However, as the study is just a mathematical model at the moment, this theory will no doubt require verification from other scientists before any firm conclusions can be drawn.

Image in text: Hawaii and the Aleutian Islands. Red and yellow arcs were considered in the probability estimates. Stars and dates show earthquakes greater than magnitude 8 pre-20th century. Butler et al


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  • earthquake,

  • hawaii,

  • tsunami,

  • Aleutian Islands,

  • 50 years