Related Story: PTWC issues tsunami advisory after Chile earthquake
An 8.2 magnitude quake hit Chile at 1:47 p.m. Hawaii time Tuesday. Four hours later, the Pacific Tsunami Warning Center issued a tsunami advisory for the islands.
On October 27, 2012, a tsunami warning was issued and evacuations ordered along coastlines throughout Hawaii after a 7.7-magnitude earthquake struck off the coast of Canada. A tsunami was expected to hit at 10:30 p.m., but when the waves arrived, they were smaller than expected.
This time around, the Pacific Tsunami Warning Center is able to get information faster if a destructive tsunami is coming. Tide measurements come now every five minutes instead of once an hour.
“What’s making this faster is they’re using a satellite to communicate with the coastal tide station,” said Gerard Fryer, senior geophysicist for the Pacific Tsunami Warning Center. “We had the satellites in 2012, we just had not gotten around to updating those particular instruments. Now, we have, so now we get all the information quickly.”
Another difference is that Tuesday’s quake hit off the coast of Chile, which is farther away and gives scientists more time to get a better handle of a possible tsunami. Officials say waves generated off Canada’s western coast in 2012 took five hours to hit Hawaii, while a potential tsunami from Chile could take about 12 to 15 hours.
What the center is still wrestling with is the line between an advisory and a warning — officials are being careful not to over-warn the public due to the inconvenience that would occur.
“If the tsunami is going to be small, we’ll have an advisory in effect anyway, and that’s what we’ve done for this particular tsunami,” said Fryer.
An animation provided by the Pacific Tsunami Warning Center shows the wave action generated by Tuesday’s quake off Chile with waves moving west toward Hawaii.
“We don’t expect to see any waves much greater than a foot or two, and that’s certainly below our threshold for issuing any kind of warning for the state of Hawaii,” said Pacific Tsunami Warning Center deputy director Stuart Weinstein.
Officials will remain at the Pacific Tsunami Warning Center overnight to monitor conditions. Waves are expected to hit around 3:24 a.m. Wednesday.
PTWC’s near real-time animation for the tsunami from northern Chile on 1 April 2014 resulting from an offshore 8.2 magnitude earthquake in the region. The animation shows simulated tsunami wave propagation for 30 hours followed by an “energy map” showing the maximum open-ocean wave heights over that period.