HONOLULU (HawaiiNewsNow) - University of Hawaii researchers say there is a 10 percent chance a large earthquake could hit the Aleutian Islands in the next 50 years and generate a devastating tsunami that could leave Hawaii under water.
"It's not a big chance, but when you magnify it out with all the potential damage it does, it's a huge potential problem," said Rhett Butler, a geophysicist at the University of Hawaii at Manoa.
Butler and paleo-biologist David Burney came to that startling conclusion through their research at Kauai's Makauwahi Cave.
Using a new carbon-dating method, they found that coral bits in the cave from a mega-tsunami date back to the 1500s.
The timeline matches up with a tsunami on Japan's Sanriku Coast in 1586.
For centuries, many thought it was generated from an earthquake in Peru, but the UH study determined that quake was too small.
Butler says it came from the Aleutian Islands from a quake stronger than a 9.0 that triggered 30-foot waves. That's three times bigger than the tsunami that wiped out Hilo in 1946.
"It's important to us in terms of Hawaii because it now gives us a better picture of the extent of that tsunami back in 1586, and gives us an idea where it affected places," Butler said.
Butler and his colleagues reached the ten percent probability after studying past quakes and tsunamis. Their work spurred the state of Hawaii to develop new extreme tsunami evacuation zones, but he says more could be done.
"It's worth spending the time and effort to stabilize buildings, look at power plants and the whole system because in Hawaii, everything is coastline and all coastlines get hit by these big tsunamis," said Butler.
Makauwahi Cave Reserve offers free guided tours. It's considered to be one of the richest fossil sites in the Pacific.