Here’s what experts say about tsunami warnings in Hawaii, Japan and Russia

An 8.8-magnitude earthquake, one of the strongest ever recorded, struck Russia’s Far East early Wednesday, prompting tsunami warnings in coastal towns in multiple countries.

The earthquake was “on what we call the Pacific Ring of Fire. This is a region around the entire Pacific Rim renowned for significant earthquakes,” Simon Boxall, lecturer in oceanography at the University of Southampton, told The Associated Press.

“The Earth is made up of these sort of geology plates, these geophysical plates, and the Earth where these plates rub, where they sort of join, we get stresses building up, and then every so often we get a sudden release of pressure and part of the seabed flips up,” Boxall said. “And so it’s that flip that causes the tsunami. And not all flips, not all earthquakes will generate these.”

Boxal said the tsunami generated by this earthquake was “not huge. It’s not one that’s going to cause mass devastation. But it will cause coastal flooding and it will cause damage and it does put lives at risk if people don’t move to high ground.”

Two magnitude 9.1 earthquakes – the Tohoku earthquake in 2011 in Japan and the 2004 Sumatra earthquake in Indonesia – caused massive tsunamis that killed thousands of people. 

Earthquake scientist Grace Sethanant said there was a reason those temblors caused much more devastating tsunamis than Wednesday’s quake.

While a magnitude 9.1 quake “might seem not so far off from the magnitude 8.8 … in terms of energy, it’s three times stronger,” Sethanant said.

“Imagine the 8.8 is, as I drop a rock in the lake, and you see the ripples. That’s the energy,” Sethanant said. “Imagine you have that rock like three times bigger. So, in terms of the earthquake movement magnitude, the energy of the 2011 and 2004 earthquakes in Sumatra and in Japan, it’s actually three to four times bigger. … And that’s why the tsunamis in those events were much more devastating.”

National Tsunami Warning Center Tsunami Warning Coordinator Dave Snider said tsunamis should be thought of more as “ocean floods” than waves.

“The most important thing to understand about a tsunami is this is not a surf wave, it’s not a wind wave,” Snider said. “A tsunami is the entire ocean column that is being lifted above that high tide level there because of that extreme movement of the Earth’s crust with the earthquake there, so this is a significant planetary event that we’ve just witnessed.”