Scientists explain why Russia's magnitude 8.8 earthquake didn't trigger a massive tsunami
When a magnitude 8.8 earthquake rocked Russia's Kamchatka Peninsula on Tuesday, officials warned that damaging tsunami waves could follow. Instead, the waves that reached Hawaii and the U.S. West Coast proved smaller than initially feared.
Despite the earthquake's massive size, tsunami waves that reached Hawaii and the U.S. West Coast shores did not cause damage, with Hawaii's Governor Josh Green reporting "not a wave of consequence."
"It's kind of a blessing to not be reporting any damage," Green told reporters early Wednesday.
The minimal impact surprised many, given that earthquakes of this magnitude rarely occur, but tsunami expert and professor Philip Liu of Texas A&M and Cornell University explained that earthquake magnitude alone doesn't determine tsunami size.
"Not every earthquake will generate a tsunami," Liu told ABC News. "It really depends on how the earthquake creates the sea bottom or sea floor deformation."
Liu explained that the vertical motion of the seafloor -- not just the earthquake's raw power -- is what matters most in tsunami formation.
"Part of the sea floor will go up, part of the sea floor will go down, and it's this vertical motion of the sea floor which generates a tsunami," he said.
In this case, despite the earthquake's significant magnitude, its rupture pattern didn't create the vertical deformation needed to generate massive waves, according to Liu. Ocean measurements showed wave heights of only 10 t0 14 feet -- relatively small for an earthquake of this size.
Judith Hubbard, an earthquake scientist and structural geologist, noted the quake occurred about 12 miles deep in a subduction zone, where such depths are typical.
"The shallow part of the subduction zone is the part that's cold enough for the rocks to slide in earthquakes," Hubbard explained to ABC News.
While coastal areas from Alaska to California remained under tsunami advisories Wednesday morning, with a warning still in effect for parts of northern California, the event demonstrated how complex earthquake-tsunami relationships can be.
Waves reached Monterey, California, at 12:48 a.m. and San Francisco by 1:12 a.m., but caused no significant issues.
The warning systems, however, performed exactly as designed. Liu praised the forecasting system's accuracy in predicting the tsunami's arrival times across the Pacific, even though the wave heights were lower than initially estimated.
Hawaiian Airlines and Alaska Airlines resumed flights Wednesday morning after temporarily pausing operations due to the warnings, marking a swift return to normal operations following the seismic event.
