The earthquake of magnitude 8.8 off the coast of the Kamchatka Peninsula of Russia sent a wave of water at the speed of a plane to Hawaii, California and the state of Washington, stimulating warnings and alarms during the night on Wednesday.
But when Tsunami waves arrived, they did not cause devastation or deaths in the United States and flood might not have seemed threatening in some places where warnings were issued.
That does not mean that Tsunami was a “bust”, which was badly forecast or that it did not represent a risk, they said researchers from earthquakes and tsunami.
“It begins to listen to Tsunami’s warning and everyone immediately thinks about the last Hollywood film they saw and then reaches 3 feet and people say: ‘What is that?'”, Said Harold Tobin, director of the seismic network of the northwest of the Pacific and professor at the University of Washington. “We should tell it as a victory that a tsunami occurred, we obtained a warning and was not the worst case.”
This is what you should know.
How strong was Kamchatka’s earthquake? And why changed so much?
The initial reports of the Kamchatka earthquake of the United States Geological Service expressed it as a magnitude of 8.0. Later, an earthquake of magnitude of 8.8 was updated.
“That is not uncommon for very, very large earthquakes in those initial minutes,” Tobin said. “Our standard algorithms to determine the size of an earthquake are quickly saturated. It’s like raising an amplifier and getting a lot of distortion.”
One of the first earthquake signals was stronger than the initial seismic reports was an initial measurement of a buoy to about 275 miles southeast of the Kamchatka Peninsula.
Boya, which is part of the dart system of the Oceanographic and Atmospheric National Administration (Tsunamis Evaluation and Reports) is connected to a seabed pressure sensor to approximately 4 miles below the surface.
The sensor recorded a 90 centimeter wave, which is surprising for Tsunami researchers.
“That is the second largest recording we saw in the world of Tsunami,” said Vasily Titov, a Tsunami senior modeler in the NOAA Pacific Environmental Laboratory, and added that he indicated that there was “a catastrophic tsunami that spread in the ocean.”
Titov said the only highest reading was from the Tōhoku 2011 earthquake and tsunami, which caused almost 16,000 deaths in Japan.
The seismic models then confirmed that Wednesday’s earthquake was a magnitude 8.8, which means that it released almost 16 times more energy than an earthquake of magnitude 8.0, according to a USGS calculation tool.
Tōhoku was much bigger.
Tobin estimated that the earthquake released 2-3 times more energy observed in Kamchatka. Titov said the tsunami in Japan was also three times bigger.
In addition, Tobin said that Tōhoku’s earthquake “produced an anomalously large displacement of the seabed”, staggering and moving more than expected water, even for an earthquake of its magnitude.
In Kamchatka, “there is likely that there is less displacement of the seabed than could have happened in the worst case or more terrible scenario for a magnitude 8.8,” said Tobin, although more research will be needed to confirm that theory.
How did the researchers do a prognosis? How good was the prognosis?
In two hours, the researchers produced a tsunami prognosis for “almost the entire Pacific and for the warning points along the coast of the United States,” Titov said, with predictions of water levels in coastal tide meters and also for flood floods.
The tsunami took about eight hours to arrive in Hawaii and 12 hours to reach the coast of California.
Titov, who helped build the models used by the forecasts that broadcast warnings of the National Warning Centers of Tsunami in Hawaii and Alaska, said that the models depend on the seismic data and the network of more than 70 darts of darts along the edge of the Pacific, which feel the pressure changes. The United States has and operates more than half of dart buoys.
Titov said the models indicated that the areas of the northern coast of Hawaii would receive tsunami waves of approximately two meters or less.
“Thread was predicted about two meters [6.5 feet] And it materialized at about 150 centimeters “or 1.5 meters [5 feet]Titov said. “It’s exactly how we want it, a little on the conservative side.”
The same trend was developed in parts of California, Titov said.
It will take some time to evaluate how well the models predicted the flood because the reports are still arriving in the reach of the floods.
“We know that floods occurred in Hawaii. We do not know exactly the scope, but because of the reports I saw on television, it seems exactly what we prejudice,” Titov said.
Why were people in Hawaii evacuated for a five -foot wave?
Yong Wei, Tsunami modeler and senior research scientist at the University of Washington and the NOAA Tsunami Research Center, said 1.5 meters. [5 foot] The tsunami wave can be very dangerous, particularly in shallow waters in Hawaii.
Tsunami waves contain much more energy than wind waves, which are much shorter in the wavelength, the period (time between the waves) and the slowest speed.
Wei said that Tsunami waves that Hawaii reached can increase the interior of “tens of meters”, produce dangerous currents and cause damage to boats and other mobile objects.
“People die. If they stay there and do not receive any warning, two meters can definitely kill people,” Wei said. “If you are on the beach, strong currents can definitely take you to the ocean and people will drown.”
Tobin said the initial warnings were conservative, but appropriate, in his opinion.
“I don’t want people to think, Oh, we had a warning and nothing happened and poop,” I can ignore it, “Tobin said. “Warnings by nature have to err a little on the side of caution.”
Was this a historical event?
No. The Kamchatka Peninsula has a long history of earthquakes.
“This was an area that was ready for another earthquake and there had been many earthquakes in that region in recent weeks,” said Breanyn Macinnes, professor of the Department of Geological Sciences of the Central University of Washington, indicating a higher risk.
In 1952, before scientists had a strong understanding of plaque tectonics, an earthquake of 9.0 magnitude hit the Kamchatka Peninsula coast in the same region, sending a tsunami to the city of Severo-Kurilsk.
“People in Russia were not really prepared for it. It was a great earthquake, a great tsunami and were taken by surprise,” Macinnes said.
Macinnes said that the tsunami produced had between 30 and 60 feet in the southern parts of the peninsula.
“Thousands of people were killed and basically the city was destroyed,” said Joanne Bourgeois, a professor of sedimentology at the University of Washington, who has been studying the history of the region’s earthquake for approximately three decades.
How would the Tsunami warning system work if the earthquake will approach home?
Kamchatka’s tsunami is a Megatust earthquake produced along a large failure in the subduction zone, when a tectonic plate is forged under another. The west coast of the United States presents a similar failure, called Cascadia subduction zone, which extends on the high seas along the west coast. UU. From northern California to northern Vancouver Island.
“This is a kind of mirror image throughout the Pacific,” Tobin said. “A 8.8 at a relatively superficial depth in Cascadia is definitely in the field of stage. We could have a similar event here.”
In fact, Cascadia has the potential to produce much larger earthquakes, Tobin said. The modeling suggests that Cascadia could produce tsunami waves up to 100 feet.
The earthquakes in the subduction zone typically produce tsunamis that reach the coast in approximately 30 minutes to an hour, Titov said, which would force the capacities of forecasting to predict the effects of the tsunami with precision along the west coast of the United States before the flood occurred.
Titov said that more seabed sensors are needed, more computer processing and innovation with artificial intelligence algorithms to accelerate the prognosis.
Tobin said that Tsunami’s successful warning on Tuesday should stimulate investment in seabed sensors and seismic monitoring stations on the high seas along the subduction zone.
“This shows the value and importance of NOAA and the USGS [U.S. Geological Survey] In these times when some of these government agencies have questioned, “Tobin said.” We would not have had a Tsunami warning if it weren’t for NOAA and the next one could be a closer event. They showed their value. ”
