There are worries that Hawaii could be hit by a tsunami caused by a mega-earthquake in the Aleutian Islands, and even though the probability is small it is worth asking whether or not the state is prepared for such an eventuality.
A new study from the University of Hawaii at Manoa suggests that a tsunami caused by a mega-earthquake in the Central Pacific is certainly possible. Scientists concluded that such an occurrence would be very rare, but there remains a 9% chance that Hawaii could be struck by a tsunami.
Important to make preparations despite small probability
“These are rare events,” says Rhett Butler, geophysicist at Hawaii Institute of Geophysics and Planetology. “They don’t happen all the time but there is a chance for them.”
Scientists have now been trying to work out what would happen if a tsunami were to hit Hawaii. One source of information is the 2011 tsunami that hit Japan, triggered by a magnitude 9.0 earthquake.
A previous study by paleo-seismologist Chris Goldfinger of Oregon State University, confirmed that these events could happen in the Pacific Northwest. Golfdingers says that the effects could be likened to five or six Hurricane Katrinas hitting land at once.
Hawaii has a history of tsunamis
Should a 9.0 mega-earthquake occur in the Aleutian Islands, it is thought that there would be $40 billion of damage and 300,000 residents would have their lives destroyed. It has been many years since Butler and his team started looking into the possibility of earthquakes and tsunamis in Hawaii.
The team found marine debris in a sinkhole in 2014, and it showed that at least one huge tsunami had hit the islands in the past. Scientists estimated that the tsunami struck around half a millennium ago, and the wave reached 9 meters high.
Butler and the researchers found that the tsunami was caused by a magnitude 9.0 earthquake off the Aleutian Islands. That particular tsunami was three times as large as the smaller tsunami which struck Hawaii in 1946, and left behind a huge amount of ocean sediment in a sinkhole.
How can residents be better prepared?
Logically the scientists then turned their attention to the issue of whether Hawaii is prepared for a future tsunami. Butler’s 2014 paper inspired the city of Honolulu to update and improve tsunami evacuation maps, which now address the possibility of a huge tsunami.
The city was convinced to do so by geophysicist Gerard Fryer, who was not involved in the 2014 study. “I’ve seen the deposit,” said Fryer. “I’m absolutely convinced it’s a tsunami, and it had to be a monster tsunami.”
Fryer believes it is necessary to make preparations for the worst tsunami that is likely to hit Hawaii in 1,000 years. Both Fryer and Butler believe that yearly risk assessments would be beneficial for officials in Hawaii to evaluate the impact of a possible mega-tsunami.
The plans that are currently in use are partly based on the 1946 tsunami, but there are fears that the next tsunami to strike could be much larger and more powerful. Residents of Hawaii would have around 4 hours to get to higher ground before a tsunami triggered by an earthquake in the Aleutian Islands hits.
Butler maintains that his research is not meant to scare people. However it does underline the importance of preparing an evacuation plan.