More than a million Americans in the northeastern US may be at risk of a tsunami due to a newly discovered fault line.
Scientists have found a roughly 45-mile-long fault in the Earth running through British Columbia, Canada, that has escaped detection for thousands of years.
Experts suspect that a major earthquake could occur in Canada because of the fault's location.
The effects of the earthquake could trigger a tsunami in the Georgia Basin area, affecting parts of Washington and British Columbia.
The discovery was made by a team including Nick Harrichhausen, a postdoctoral researcher at the Université Grenoble Alpes in France.
If an earthquake at this newly discovered fault pushes up the seafloor of Haro Strait, it could displace enough water to cause a tsunami in the surrounding Georgia Basin.
An earthquake can be followed by a tsunami, even if the geological event only pushes the land up a few meters
Harrichhausen and his colleagues discovered that the two huge boulders in the fault line slid against each other, causing a large earthquake several thousand years ago.
He told DailyMail.com that this could potentially happen again.
Because of the numerous geological fault lines in the Pacific Northwest (not just the newly discovered ones), he encourages people to stay prepared for a possible earthquake by stocking up on several days' worth of food, water, medicine and emergency supplies.
The geological intersection, called the XEOLXELEK-Elk Lake Fault (XELF for short), runs diagonally across the Saanich Peninsula north of Victoria from northwest to southeast.
The reason for its possible destruction, Harrichhausen said, is that the side.
“Because we are documenting dip-slip, which caused a vertical shift of the Earth's surface, and the fact that this fault would likely rupture underwater, there is a possibility that an earthquake on this fault would trigger a local tsunami in the Georgia Basin,” says Harrichhausen.
The Georgia Basin includes the cities of Bellingham, Seattle, Tacoma and Olympia in the US, and Vancouver, Victoria and Whistler in Canada.
'Given the XEOLXELEK-Elk Lake fault, where an earthquake occurred in the Holocene (last 12,000 years), we should consider that it is active and that another earthquake of similar magnitude (or less) can take place like the one we observe in our study. study,” he said.
This ancient earthquake, measuring 6.1 to 7.6 on the Richter scale, shook the region along this fault line between 4,700 and 2,300 years ago, Harrichhausen and his colleagues found.
For comparison, an M 6 earthquake has a force equivalent to 60 million kilograms of TNT, and an M 7 has a force of 20 billion kilograms.
“An earthquake of this magnitude would be damaging, especially given the proximity to urban areas,” Harrichhausen said. “It is impossible to predict in terms of timeline when the next earthquake will be.”
Not only could it shake the more than 400,000 people in the immediate vicinity of the fault line, but it could also trigger a tsunami in the greater region, he explained.
“This particular fault will certainly impact people in the US as we map it to potentially extend under the Haro Strait and the US border to the Devils Mountain fault in Washington state,” Harrichhausen said.
“Thus, a fault could extend into the United States, and even if it didn't, a large earthquake on Lake XEOLXELEK-Elk would be felt by people in the northern Puget Sound area.”
However, calculating when an event like this might occur is a challenge, even for geologists.
“All we can do is look at the recurrence interval of past earthquakes (the average number of years between earthquakes),” he said.
And the new study is limited in making this calculation because it requires at least two separate earthquakes to estimate the time between ruptures.
“Please note that this is a very rough calculation as the time between earthquakes can vary greatly,” he added. 'Therefore, more studies may allow us to better understand the danger posed by the error.'
Harrichausen and his colleagues explored the fault line by digging a trench across it, allowing them to look for signs of earthquakes and fault line shifts in geological history.
These signs came in the form of changes in the magnetic field.
Minerals in rocks have different levels of magnetism, so measuring these differences can reveal whether large rock formations formed at the same time and remained in shape, or whether they broke up.
What they found was that, some time after glaciers carved out the landscape, the slip-dip fault had shifted the land.
They calculated that this would be sometime in the last 12,000 years, probably between 4,700 and 2,300 years ago.
The research appeared in the journal this week Tectonics.
If another earthquake occurs, Harrichhausen said people in the region can take some basic steps to prepare.
'Earthquake preparedness experts suggest that people secure large furniture and appliances, prepare a disaster plan, organize disaster supplies for at least three days and up to two weeks of self-reliance (food, water, medicine, etc.) and take steps to avoid financial problems minimize,” he said.
“Of course, when an earthquake starts, you have to drop, cover up and hold on.”