A huge, 8.1M underwater earthquake struck in a remote area between New Zealand and Tonga Thursday morning, and the Pacific Tsunami Warning Center is saying that tsunamis may be possible in Hawaii later today as a result.
It's not yet a certainty, and an official tsunami warning has not been issued for Hawaii. As the Associated Press reports, an earlier warning the agency issued for American Samoa was later downgraded to an advisory, but Hawaii is currently under a tsunami watch.
As scientists assess whether the tsunami threat is real, they say the first waves would arrive on the shores of Hawaii at 4:35 local time, or 6:35 p.m. Pacific Time.
The earthquake, the third in a row in the region, hit at 11:28 a.m. Pacific Time in the area of the Kermadec Islands. Seismologist Dr. Lucy Jones said on Twitter that an early 7.4M quake in the same region was likely a foreshock, and an earlier 7.3M quake closer to New Zealand but near a tectonic plate boundary was "more ambiguous."
"It is far enough away that it is at the very edge of where we see statistical evidence of triggering," Jones says. "'Did it trigger the M8.1?' - seismologists will be arguing."
The M7.3 is also near the plate boundary but has a different focal mechanism so doesn't look like an interface event. It is far enough away that it is at the very edge of where we see statistical evidence of triggering. "Did it trigger the M8.1?" - seismologists will be arguing— Dr. Lucy Jones (@DrLucyJones) March 4, 2021
Jones also says that the likelihood of a tsunami being triggered is fairly low, especially at a distance as far away as Hawaii.
"The Japanese tsunami [in 2011] was from a M9.0 that moved over 30 TIMES more water than this event," Jones says. "Geometric spreading means you need to move a lot of water to still see a measurable tsunami on the other side of the ocean. M9s do it. M8s much less so."
Incidentally, and crazily, a February 13 quake off the Japanese coast is considered a late aftershock of the 2011 earthquake, Jones said.
Photo: Karsten Winegeart