A DEVASTATING 80-foot tsunami could strike the east coast of America at any moment, a top scientist has warned.
New York, Boston and Miami could all be struck by the monster wave, while Central and South American tourist hotspots like the Bahamas, Barbados and Trinidad and Tobago would also in the firing line.
The tsunami, which could hit populated shores in just 15 minutes from a magnitude nine undersea overdue earthquake, would be caused by seismic activity in the Cascadia Subduction Zone – and should happen on average every 240 years.
But scientists, who warn that more needs to be done to prepare for the impending disaster, say the last one was 315 years ago -so it is 75 years overdue.
Chris Goldfinger, Oregon State earthquake geologist, is warning of the imminent risk.
The problem lies with the subduction zone where it meets the Oceanic Plate and is slowly forced beneath the North American plate
The Cascadia Subduction Zone is seventy miles off America’s Pacific Northwest and stretches all the way from Vancouver Island to Northern California.
Mr Goldfinger said: “It buckles upward and it gets pushed backward like a spring until eventually, after a few hundred years, it just has to let go.”
This is what triggers a massive tidal surge and the tsunami
The scientist and his team were the first to discover the next |”Big One” is long over due.
His team has collected samples of sediment from the ocean floor to look at movement.
They say that the signs that came before the 2011 Japanese tsunami which claimed 16,000 lives are happening around the subduction zone, but the US was not prepared for its effects.
Fears have heightened after a video emerged of a surge of water submerging Joe Creek near Pacific Beach in Washington state.
The footage, shot by Irene Sumi, shows a “rogue” wave rolling in and reaching inland.
She said the wave brought in logs and debris, while witnesses were left shaken up by the unexpected surge, and fear it could be a warning before the Big One.
He said: “There’s nothing that compares to a magnitude 9 earthquake that North America has experienced in human history.”
Although preparations are underway.
Students at Grays Harbor County School in Westport, Washington, have regular drills going to the top floor in the event of a 15-minute warning.
But scents have warned it would not be high enough at its current height.
Paula Akerlund, school superintendent, said: “Scientists tell us it will happen at some point.
“It’s very unpredictable as to when. So we, we need to be prepared.”
Builders have been hired to put up north America’s first ever vertical evacuation structure on top of the school.
The structure will be 44 feet-high with 14 inch walls audits hoped it would provide safety high enough for students and staff.
Kenneth Murphy, Federal Emergency Management Agency’s regional administrator, said: “I would never say we are ready.
“At least 10,000 plus would be killed from the tsunami if a magnitude quake hit.
“They tremendously go up from a magnitude quake.
“We’re talking numbers that this nation, I’m not sure, is really prepared to deal with.”
Some cities are now requiring new buildings are built to withstand a major earthquake, but it does not apply to existing older ones.
But state and military authorities say adequate emergency plans are in place.
“There was a series of objections. But independent modelling has shown the same things as me. My response is it’s better to know so we can prepare.
“When the elite of the world start preparing for doomsday, that is a very troubling sign. And right now the elite appear to be quietly preparing for disaster like never before.Want to Be on Survivalist?Here’s your chance.Watch this free video.
What Is a Tsunami?
A tsunami is a set of powerful ocean waves most commonly caused by a large earthquake or landslide that occurs near or under the ocean. Scientists do not use the term “tidal wave” because these waves are not caused by tides. Tsunami waves are unlike typical ocean waves generated by wind and storms. When tsunami waves approach shore, they behave like a very fast-moving tide that extends far inland.
A rule of thumb is that if you see the tsunami, it is already too late to outrun it. Most tsunamis do not “break” like the curling, wind-generated waves popular with surfers. Even “small” tsunamis (for example, 6 ft high) are associated with extremely strong currents, capable of knocking people off their feet. As with many natural phenomena, tsunamis can range in size from micro-tsunamis detectable only by sensitive instruments on the ocean floor to mega-tsunamis that can affect the coastlines of entire oceans, such as the Indian Ocean tsunami of 2004.
Because of complex interactions with the coast, tsunami waves can persist for many hours. If you hear a tsunami warning or if you feel strong shaking at the coast or observe highly unusual wave activity (for example, the sea withdrawing far from shore), it is important to move to high ground and stay away from the coast until wave activity has subsided (generally several hours to days).
Data We Can Use to Answer the Question “Could It Happen Here?”
Three primary sources of information can be used to answer the question “Could it happen here?”:
1) tsunami catalogs of historical events,
2) the age of geologic deposits left by great earthquakes and tsunamis (see related Sound Waves article “Group Aims to Distinguish Tsunami Deposits from Large-Storm Deposits in the Geologic Record”.
3) computer simulations of tsunamis from potential great earthquakes and landslides around the world.
This article focuses on the first source, historical information, taken mainly from the worldwide catalog of historical tsunamis maintained by NOAA‘s National Geophysical Data Center (NGDC). This catalog includes two types of measurements: runup observations from eyewitness accounts, and wave-height readings from tide-gauge stations, most often located in harbors.
The term “runup” refers to the vertical height a wave reaches above sea level as it washes ashore, “wave height” to the vertical measurement of the wave before it reaches shore, and “inundation distance” to the horizontal distance a tsunami reaches landward from the shoreline. More information on tsunami measurements can be found on the NGDC Tsunami Introduction Web page.
Hawai’i has a long recorded history of tsunamis—both “teletsunamis” (also called “far-field tsunamis”) from earthquakes around the Pacific rim, and “local tsunamis” from earthquakes and landslides near Hawai’i. The Pacific Disaster Center reports that tsunamis have accounted for more lost lives in Hawai’i than the total of all other local disasters. In the 20th century, an estimated 221 people were killed by tsunamis on the islands of Hawai’i.
One of the largest and most devastating tsunamis that Hawai’i has experienced was a teletsunami in 1946 from an earthquake along the Aleutian subduction zone. Runup heights reached a maximum of 33 to 55 ft and 159 people were killed. Damage was more than $26 million ($255 million in today’s dollars). Other important teletsunamis include one from the 1960 magnitude 9.5 earthquake in southern Chile and one from the 1964 magnitude 9.2 earthquake in the Gulf of Alaska. The May 22, 1960, Chile earthquake generated a 35-ft-high wave, causing 61 deaths and $23 million damage (about $150 million in today’s dollars). Hawai’i has also been hit by local tsunamis, primarily from earthquakes and large-scale subsidence along the south flank of Kilauea.
Because Alaska, including the Aleutian Islands, is bordered on the south by a major subduction zone capable of generating large earthquakes, Alaska has sustained many damaging tsunamis. By far, the one that stands out is the tsunami generated by the 1964 magnitude 9.2 earthquake in the Gulf of Alaska. Not only was a Pacific-wide tsunami generated by this great earthquake, but landslides in coastal fiords, such as Port Valdez, also generated localized, extremely damaging waves.
The 1964 tsunami caused damage and loss of life across the Pacific. The West Coast & Alaska Tsunami Warning Center in Palmer, AK, indicates that the 1964 tsunami was the most disastrous tsunami to hit the U.S. west coast, causing many fatalities and financial losses.
U.S. West Coast
The historical record of tsunamis along the U.S. west coast consists mainly of teletsunamis generated by large earthquakes around the Pacific Rim. Of the teletsunamis that have struck the West Coast, the 1964 Gulf of Alaska tsunami caused the most extensive damage, particularly in Crescent City, CA, where at least 10 deaths occurred.
Potentially tsunamigenic fault structures exist locally offshore the U.S. west coast, most notably the Cascadia subduction zone—an offshore fault system about 1,200 km (750 mi) long that extends from northern California to southern Canada and accommodates motion between the Pacific and North American tectonic plates at a rate of about 40 mm/yr (1.6 in./yr). This subduction zone is believed to have most recently ruptured in a magnitude 9.0 earthquake in 1700; the resulting tsunami was recorded in historical accounts in northern Japan.
Geologic evidence of submerged vegetation indicates that large or great earthquakes (magnitude 8 to 9) have occurred on average every 500 years along this zone. Great ruptures along this subduction zone would most likely cause local and possibly oceanwide tsunamis that could affect the Western United States.
U.S. Gulf Coast
In historical times, tsunami waves recorded along the Gulf Coast have all been less than 1 m high. Those reported from the 1964 Gulf of Alaska earthquake as felt in Louisiana and Texas are technically termed seiches—oscillations of a body of water typically caused by atmospheric disturbances but in this case caused by ground motion from the earthquake. Seiches can also occur in lakes from earthquake movements.
U.S. East Coast
Because the only major subduction zones in the Atlantic Ocean are along the Caribbean Sea, tsunamis have been relatively infrequent here in comparison with the Pacific Ocean. The most famous Atlantic tsunami was the 1755 Lisbon tsunami, generated by an earthquake on a fault offshore Portugal.
Teletsunamis from that earthquake were reported in Newfoundland (Canada) and islands in the Caribbean Sea. The most noteworthy local tsunami in North America resulted from the 1929 magnitude 7.3 Grand Banks earthquake near Newfoundland. In this complex event, most, if not all, of the tsunami energy may have been triggered by a submarine landslide.
The maximum tsunami runup was 2 to 7 m, which was concentrated on the coast of Newfoundland, although it was recorded as far south as South Carolina. A couple of tsunamis reported from Caribbean earthquakes had runups less than 1 m.
Puerto Rico and the U.S. Virgin Islands
Puerto Rico and the U.S. Virgin Islands are more susceptible than other places in the Eastern United States, because a subduction zone capable of generating large earthquakes lies beneath the Caribbean Sea. Tsunamis have struck Puerto Rico and the Virgin Islands more than six times in recorded history.
The tsunami with the greatest amount of damage in Puerto Rico was generated in 1918 by an earthquake off the Mona Passage, east of the island. With a maximum runup of 6 m, the tsunami itself killed 40 people; an additional 76 people were killed by the earthquake. The Caribbean region as a whole has a history of earthquakes that have caused damaging tsunamis.
Other U.S. Territories
Other territories of the United States are adjacent to large subduction zones. Guam and the Marianas Islands are next to the Marianas Trench. American Samoa is affected by earthquakes about 100 mi away along the Tonga-Kermadec Trench.