Archive for In The News

3.6 magnitude earthquake rattles Kamloops

Some residents of Kamloops, B.C., were woken up this morning by a 3.6 magnitude earthquake.

Natural Resources Canada says the quake happened at 1:48 a.m. PT Wednesday just west of the city.

Aleece Laird was asleep when the shaking began, and like others, she first assumed it was a train passing her home, but then realized the shaking was too strong.

“There was this jolt and it woke both my husband and I up, and in the classic move that moms make when you are having to stop in your car and you put your hand over your passenger, I did that to my husband, wanting to make sure that he did not fall out of bed.”

There have been no reports of damage.

Source: http://www.cbc.ca/news/canada/british-columbia/earthquake-kamloops-1.3367574

Posted in: In The News

Leave a Comment (0) →

Earthquake in Northern B.C. caused by fracking, says regulator

British Columbia’s energy regulator has confirmed that a 4.6 magnitude earthquake in northeast B.C. in August of this year was caused by a nearby fracking operation.

“This seismic event was caused by hydraulic fracturing,” said Ken Paulson, CEO of the B.C. Oil and Gas Commission. Paulson said fewer than one per cent of fracking operations trigger seismic activity, and those quakes tend to be low magnitude and cause little damage.

The quake struck in August, about 110 kilometres northwest of Fort St. John, near a gas fracking site operated by Progress Energy.

Hydraulic fracturing or “fracking” is a process that involves pumping a mixture of water, sand and chemicals underground at high pressure to fracture rock and release trapped natural gas.

Studies have linked fracking with earthquakes in the U.K., Oklahoma, and in B.C.

Largest fracking-related quake

The epicentre of the August quake was three kilometres from the Progress Energy fracking site. The operation shut temporarily immediately after the quake but soon restarted with continued monitoring.

Fracking operations have previously triggered small earthquakes in B.C. In the U.S., the disposal of frack waste has triggered larger quakes. But scientists said last summer that the 4.6 magnitude August quake may be the largest in the world caused by hydraulic fracturing.

No one was injured in the earthquake and there was no damage reported, but shaking could be felt for several kilometres.

Experts say it is unlikely any fracking-related earthquakes in the future will cause damage.

“This level of earthquake, although sounds scary, but in terms of the actual seismic damage, magnitude 4.6 is very unlikely to cause significant damage,” said Honn Kao, a research scientist with the Geological Survey of Canada.

In a written statement, Progress Energy says it takes the incident very seriously, and is closely monitoring seismic activity near its frack sites.

Meanwhile, B.C.’s energy regulator says it continues to closely monitor seismic activity and B.C.’s gas fields, and that it’s still business as usual.

Balance between development and public safety

Kao says there are existing industry protocols in place regarding fracking-caused earthquakes.

“We’ve already had a meeting together — workshop together with everybody to discuss the best practice protocol that’s currently in place.”

He says the regulator’s acknowledgement that this 4.6 earthquake was caused by fracking means those protocols can now be updated to better protect the public.

“The key issue really is if we have all the necessary practice protocol in place so that we can set the level to a certain acceptable risk. Then the community will feel much less afraid and therefore we can reach a very nice balanced approach between the development and the public safety.

Source: http://www.cbc.ca/news/canada/british-columbia/earthquake-northeastern-b-c-progress-energy-fracking-1.3367081

Posted in: In The News

Leave a Comment (0) →

Record number of British Columbians participate in ShakeOut earthquake drill

A record number of British Columbians – 785,000 – took part in the Great British Columbia ShakeOut on Thursday, joining millions around the world, the Insurance Bureau of Canada (IBC) said.

“Since launching the Great British Columbia ShakeOut in 2011, we’ve seen participation jump from 470,000 to a new record of 785,000 in 2015,” said Dave Cockle, president of the BC Earthquake Alliance, in a press release. “I think that reflects an increased understanding of the earthquake risk in B.C. and the need to be prepared. We’re on our way to creating a culture of preparedness and making British Columbia a more resilient province.”

ShakeOutBC earthquake drills are held the third Thursday of every October. They encourage people at home, school and work to practice “Drop, Cover and Hold On” and consider the importance of overall preparedness to be better prepared to survive and recover quickly following an earthquake. Dropping to the ground prevents the earthquake from dropping a person first, while taking cover and holding on helps protect people from flying objects and falling debris, the IBC explained.

The more than 785,000 that registered for this year’s “Drop, Cover and Hold On” drill surpassed the 2014 total by more than 41,000, the IBC reported. Worldwide, nearly 41.5 million people have participated in Great ShakeOut drills to date in 2015.

Naomi Yamamoto, British Columbia’s Minister of State for Emergency Preparedness and Vancouver Mayor Gregor Robertson, along with representatives from the BC Earthquake Alliance, IBC and the City of Vancouver, helped mark the event by participating in the “Drop, Cover and Hold On” drill during Earthquake Day at the Vancouver Public Library.

Yamamoto said that the drill is the safest action to take during an earthquake. “Given that BC has thousands of earthquakes annually, The Great British Columbia ShakeOut serves as an important reminder that every British Columbian must be prepared to be self-sufficient during the initial days after an earthquake,” she said, adding that all provincial residents are encouraged to have an emergency plan and emergency kits prepared.

More than 3,000 earthquakes occur in B.C. every year. “Most are too small to be felt, but the risk of one capable of causing major damage is real,” the release said, adding that there is a one in 10 chance for a “destructive megathrust earthquake in B.C. within the next 50 years.”

Source: http://www.canadianunderwriter.ca/news/record-number-of-british-columbians-participate-in-shakeout-earthquake-drill/1003849178/?&er=NA

Posted in: In The News

Leave a Comment (0) →

Great BC ShakeOut drills, seismic upgrades move schools toward earthquake safety

Over a hundred schools have been rated as high risk by the ministry and require seismic upgrades.

As thousands of British Columbians practiced the “drop, cover and hold on” drill as part of the Great BC ShakeOut this morning, Kitsilano Secondary School moved one step closer to seismic safety.

The first stage of the school’s seismic upgrades was completed today with the official opening of a new wing. It is all part of the provincial government’s $57.8 million seismic upgrades for the school.

The school has been a high priority for seismic upgrades for years, but there was much desire to maintain the school’s heritage facade.

“We are committed to upgrading everything that needs seismic upgrades,” said Mike Bernier, Minister of Education.

There are five other schools currently undergoing seismic upgrades in the province.

But there are over a hundred schools have been rated as high risk by the ministry because they are deemed vulnerable to damage and structural failure during an earthquake.

The government says money isn’t the issue when it comes to upgrading the other schools.

“It is now at the planning stage. It is working with the school districts,” said Bernier.

The provincial government has earmarked $500 million for seismic upgrades to 45 schools.

Practice run

The announcement comes as more than 780,000 British Columbians practiced how to “drop, cover and hold on,” as part of the Great BC ShakeOut on Thursday morning.

The drill is designed to raise earthquake preparedness because of the risk a major earthquake could strike the province at any time.

“In the last 30 days in British Columbia, we’ve had almost 400 small earthquakes. We have to be aware that this is happening on a daily basis and it really could be at any time that we experience this,” said Miranda Myles, volunteer with ShakeOut.

Organizers say during an earthquake you should:

DROP to the ground in simulation of a major earthquake;
Take COVER by getting under a sturdy desk or table, and
HOLD ON to it for 60 seconds

Source: http://www.cbc.ca/news/canada/british-columbia/school-seismic-shakeout-1.3272746

Posted in: In The News

Leave a Comment (0) →

UBC expert helps B.C. prepare for an earthquake

October 15 is officially ShakeOut BC Day, and more than 750,000 British Columbians are expected to participate in this year’s drill. In this Q&A, UBC earthquake safety expert Carlos Ventura talks about the nature of earthquakes and what’s being done to ensure that the buildings where we live, study and work are earthquake-ready.

There’s a lot of talk about B.C. being overdue for the Big One: an earthquake of 9.0 magnitude or greater. Is the province ready for a major quake?

It’s important to understand that it’s not only the magnitude of the earthquake that determines its impact. Smaller earthquakes, if they occur near urban areas, can cause significant damage.

That said, the province is more prepared for an earthquake in the sense that government, scientists, educators, and the news media have been actively spreading safety awareness.

Everyone should know the drill by heart: drop, cover and hold on. Recognize quickly that it is an earthquake and don’t panic. Hide under a sturdy table or desk, or crouch near an inside corner of the building. Stay there until the shaking stops. Many earthquake-related injuries in North America are due to falling objects, not buildings collapsing. Once the shaking has stopped, leave your house or building if you can do so safely, and grab your emergency kit if you have one.

How important are emergency kits? What’s in yours?

Because an earthquake can affect a wide region, you could lose power, water, heat and food for a period of time. An emergency kit will help you stay warm and treat minor injuries.

My survival kit at home and in the office contains water, dried food, a blanket, a hand radio, and some simple medical supplies. Some people think of their camping gear as a survival kit.

There’s concern that not all B.C. schools are earthquake-ready.

Vancouver has made great strides, but for a number of reasons, a significant number of school buildings in the city are still in the high-risk category. However, many school districts outside Vancouver have done or are completing their seismic upgrades. Earthquake shelters have also been identified in many schools, such as gyms or other large spaces that are designed to perform very well and stay operational during an earthquake.

For new buildings, seismic readiness is not as big an issue because they are designed to comply with building standards, which specify the amount of shaking that a building must be able to withstand. But most of the older buildings, especially those built before the 1970s, need to be retrofitted to become compliant.

You say it’s impossible to accurately predict when an earthquake will happen. Does B.C. have an early warning system at least?

Yes. At the Earthquake Engineering Research Facility at UBC, we’re working on an early warning system consisting of sensors installed at many different locations to detect and measure the different waves generated by an earthquake: the P (primary) waves, the S (secondary) waves and the surface waves, which are more damaging.

Depending on the waves’ characteristics, the system will generate an alarm, and people will have a few seconds or almost a minute to take shelter, depending on their distance from the epicentre of the earthquake. A few seconds’ warning could be enough to save your life.

This early warning system was tested in a pilot project with Vancouver’s Catholic schools and is currently being rolled out across the Lower Mainland. Eventually we hope to add Vancouver Island into this warning system as well.

We’re also working with the Ministry of Transportation and Infrastructure to install sensors near highways and other public structures. The more sensors there are, the more warning we’ll get and the safer we’ll be. Imagine being able to shut down trains quickly during an earthquake, postpone surgery, or stop machinery. An early warning system will allow us to do that and minimize damage.

UBC, the City of Vancouver, and the Vancouver Public Library are holding Earthquake Day on October 15 to raise earthquake awareness. This community outreach event complements ShakeOut BC Day and is one of UBC’s many Centennial initiatives.

Source: http://news.ubc.ca/2015/10/14/ubc-expert-helps-b-c-prepare-for-an-earthquake/

Posted in: In The News

Leave a Comment (0) →

Moderate earthquake off west coast of B.C.

Magnitude 5.7 earthquake 208 kilometres west of Port Hardy was lightly felt.

A 5.7 magnitude earthquake was detected Thursday at 6:48 a.m. PT, 208 kilometres west of Port Hardy, B.C., in the Pacific Ocean.

There is no tsunami threat, nor was there any damage, although there were reports the quake was “lightly felt” in Port Hardy.

Seismologist Alison Bird said the earthquake took place in an active area, but is not significant.

Earthquakes that register between 5 and 5.9 in magnitude are classified as moderate.

Source: http://www.cbc.ca/news/canada/british-columbia/moderate-earthquake-off-west-coast-of-b-c-1.3241719

Posted in: In The News

Leave a Comment (0) →

Vancouver earthquake scenario predicts up to 10,000 casualties

Vancouver earthquake scenario predicts up to 10,000 casualties

Minister of emergency preparedness says people are not prepared, as evidenced by recent windstorm.

Roughly 10,000 people in the Lower Mainland might die if a shallow earthquake struck directly beneath the city of Vancouver — that’s the projection from a worst-case scenario in the provincial government’s Earthquake Immediate Response Plan.

That number — combined with the recent windstorm in Southern B.C. — has the minister responsible for emergency preparedness in B.C. concerned that many are not prepared for the possibility of a large earthquake.

The scenario, laid out in a report released at the end of June, describes the event occurring on an ordinary January day, following a few days of continuous heavy rain that has caused some flooding.

The downtown cores of the region’s cities are full, and many parents and caregivers are on the road after having picked up children from school early to avoid traffic delays in the wet weather.

Then suddenly, a rumbling sound like a freight train is heard, followed by 10 to 20 seconds of violent shaking.

The scenario goes on to describe roads cracking, buildings collapsing, and fires starting through damaged electrical power and gas lines.

Impact on Victoria modeled

Two separate earthquakes, both shallow, were modeled for the report.

For the Greater Vancouver region, the earthquake was based on the largest historical earthquake in the region, a magnitude 7.3 earthquake which took place on Vancouver island in 1946.

In the second scenario a magnitude 7.0 earthquake was modeled for the Greater Victoria region, based on an existing fault that has not been active in the last 10,000 years.

“Both of these separate events have the potential to occur, although the probability is low,” the report said.

“These represent the worst-case scenarios for an earthquake affecting B.C. due to injuries, damage, and greatest economic impact.”

The anticipated effects include 52 injuries per 1,000 people in the Greater Victoria area (or Capital Regional District) and Metro Vancouver, and 4 casualties per 1,000 people.

The report goes on to detail how the province would work with various jurisdictions to coordinate an emergency response plan.

Minister is worried

Naomi Yamamoto, B.C.’s minister of state responsible for emergency preparedness, said these are “huge numbers.”

“I’m quite concerned that most people aren’t prepared, as evidenced by the recent windstorm [in southwestern B.C.]”

Yamamoto said the province will increase efforts to make British Columbians more aware of earthquake preparedness.

She said the province will continue to spend money to seismically upgrade schools, hospitals and other buildings, as well as roads and bridges.

In March 2015 it was reported that a deadline announced a decade ago to upgrade all the province’s schools by 2020 was pushed back between five and 10 years for various districts.

When asked if this new scenario would motivate the government to speed up that time frame, the Yamamoto replied that a number of projects require seismic upgrading.

“We never know when an earthquake will occur,” she said.

“It could be in the middle of the night, it could be on a weekend, it could be tomorrow. So schools are important, but so is the importance of seismically upgrading our highway systems and bridges. We also need to make sure that emergency vehicles can actually get to hospitals.”

Numbers are not surprising

Carlos Ventura, the director of the earthquake engineering research facility at the University of B.C., said other studies have previously showed that this extent of damage is possible.

“This is what you might expect for a region with a population that we have here,” he said.

“So the numbers are not unrealistic. They are scary numbers, but it’s good to know what could happen it we don’t take steps to protect ourselves and minimize the potential damage from an earthquake.”

Ventura said a major concern for the region is the number of older brick buildings, which are more likely to collapse in a severe earthquake, as well as buildings built in the 1960s or 1970s with concrete that doesn’t meet today’s standards.

The report forecasts that 12 per cent of buildings in Metro Vancouver region are most likely to receive complete damage, compared to 11 per cent in the Greater Victoria area.

However, he added that many buildings in the region have been designed to withstand earthquakes — and instead the threat of injury could come from falling or flying objects inside the building.

“The major problem we have is to fix the interior of buildings, to prevent those kinds of injuries to people,” he said.

Yamamoto said that the recent windstorm in B.C. has highlighted the importance of people being able to access information during an emergency, and being prepared.

“We need to make sure that people have emergency kits on hand. We need to make sure that the kits provide enough water for at least three days, food for thee days, batteries, and hand-powered, hand-cranked flashlights.”

Source: http://www.cbc.ca/news/canada/british-columbia/vancouver-earthquake-scenario-predicts-up-to-10-000-casualties-1.3213680

Posted in: In The News

Leave a Comment (0) →

Fraser Valley shaken by second earthquake this week

Mission’s 2.6 magnitude quake early Saturday morning comes after Abbotsford area hit.

A small earthquake shook the Fraser Valley early this morning just after 4:30 a.m. PT.

It measured a magnitude of 2.6 and was centred east of Mission, according to the U.S. Geological Survey.

This is the second quake this week, following a 2.4 magnitude one that registered near Abbotsford on Thursday, August 27.

Source: http://www.cbc.ca/news/canada/british-columbia/fraser-valley-shaken-by-second-earthquake-this-week-1.3208598

Posted in: In The News

Leave a Comment (0) →

Fracking-induced earthquakes could leave workers vulnerable, says geophysicist

Seismic scientist David Eaton says Canada’s fracking-induced quakes are the biggest in the world.

A leading seismic scientist says B.C.’s energy infrastructure and gasfield workers may be vulnerable to earthquakes caused by fracking.

Earthquakes triggered by fracking have been felt in Fort Nelson and Fort St. John, but University of Calgary geophysicist David Eaton says the shaking is strongest in remote areas near fracking sites.

“Certainly in the immediate area where there’s infrastructure established by the oil and gas industry, including pipelines and well bore casings, then it’s something that really requires some careful analysis,” said Eaton.

Fracking, the common name for hydraulic fracturing, is the process of injecting water, sand and chemicals at high pressure deep underground to break rock and free gas.

New research shows fracking-induced quakes are shallow, so they trigger stronger ground motion and shaking — potentially damaging in places without much earthquake preparedness.

Eaton, part of a national research network looking into “induced seismicity” — earthquakes caused by fracking — in northern B.C. and Alberta, says energy regulators are taking the issue “very seriously.”

The quakes are hitting far from cities and towns, he said, but pipelines, gas wells and workers at fracking sites are all vulnerable.

“If people are being shaken up by ground motions, then it makes it a matter of public concern,” he said.

WorkSafeBC spokeswoman Trish Knight Chernecki said she’s not aware of any workplace injuries caused by seismic activity.

“Our officers in the northeast of B.C. continue to inspect oil and gas workplaces and hold employers accountable for the health and safety of their workers including maintaining the safety of industry infrastructure,” she said.

Fracking triggered 2014 quake

Eaton’s concerns come amid the news that fracking triggered a 4.4-magnitude earthquake in northeastern B.C. last year, one of world’s largest earthquakes ever linked to the controversial process.

The 4.4-magnitude quake was felt in Fort St. John and Fort Nelson in August 2014. It was preceded by a 3.8-magnitude earthquake in late July, also caused by fracking.

In January, Alberta’s energy regulator reported fracking likely caused a 4.4-magnitude earthquake in the northern town of Fox Creek.

Meanwhile, B.C.’s Oil and Gas Commission continues to investigate whether a 4.6-magnitude quake only three kilometres from a fracking site was triggered by hydraulic fracturing this month.

Why is Canada different?

Eaton said the fracking-related earthquakes seen in Canada are different from those felt in the U.S.. In the U.S., larger earthquakes have been triggered — but they’re due to disposal of fracking wastewater, not fracking itself.

“Of all the induced earthquakes that are directly related to hydraulic fracturing, the ones we’re seeing in Western Canada are certainly at the top,” said Eaton.

“Worldwide [these quakes are] the highest magnitude events that are attributed to hydraulic fracturing anywhere in the world.”

Research is ongoing into why such large quakes are being triggered in Canada by fracking alone.

“It’s much different in Western Canada than in Oklahoma and Kansas — why is it different? That’s the topic of intensive research. It’s too early to say right now.”

Source: http://www.cbc.ca/news/canada/british-columbia/fracking-induced-earthquakes-could-leave-workers-vulnerable-says-geophysicist-1.3205262

Posted in: In The News

Leave a Comment (0) →

The Really Big One

An earthquake will destroy a sizable portion of the coastal Northwest. The question is when.

When the 2011 earthquake and tsunami struck Tohoku, Japan, Chris Goldfinger was two hundred miles away, in the city of Kashiwa, at an international meeting on seismology. As the shaking started, everyone in the room began to laugh. Earthquakes are common in Japan—that one was the third of the week—and the participants were, after all, at a seismology conference. Then everyone in the room checked the time.

Seismologists know that how long an earthquake lasts is a decent proxy for its magnitude. The 1989 earthquake in Loma Prieta, California, which killed sixty-three people and caused six billion dollars’ worth of damage, lasted about fifteen seconds and had a magnitude of 6.9. A thirty-second earthquake generally has a magnitude in the mid-sevens. A minute-long quake is in the high sevens, a two-minute quake has entered the eights, and a three-minute quake is in the high eights. By four minutes, an earthquake has hit magnitude 9.0.

When Goldfinger looked at his watch, it was quarter to three. The conference was wrapping up for the day. He was thinking about sushi. The speaker at the lectern was wondering if he should carry on with his talk. The earthquake was not particularly strong. Then it ticked past the sixty-second mark, making it longer than the others that week. The shaking intensified. The seats in the conference room were small plastic desks with wheels. Goldfinger, who is tall and solidly built, thought, No way am I crouching under one of those for cover. At a minute and a half, everyone in the room got up and went outside.

It was March. There was a chill in the air, and snow flurries, but no snow on the ground. Nor, from the feel of it, was there ground on the ground. The earth snapped and popped and rippled. It was, Goldfinger thought, like driving through rocky terrain in a vehicle with no shocks, if both the vehicle and the terrain were also on a raft in high seas. The quake passed the two-minute mark. The trees, still hung with the previous autumn’s dead leaves, were making a strange rattling sound. The flagpole atop the building he and his colleagues had just vacated was whipping through an arc of forty degrees. The building itself was base-isolated, a seismic-safety technology in which the body of a structure rests on movable bearings rather than directly on its foundation. Goldfinger lurched over to take a look. The base was lurching, too, back and forth a foot at a time, digging a trench in the yard. He thought better of it, and lurched away. His watch swept past the three-minute mark and kept going.

Oh, shit, Goldfinger thought, although not in dread, at first: in amazement. For decades, seismologists had believed that Japan could not experience an earthquake stronger than magnitude 8.4. In 2005, however, at a conference in Hokudan, a Japanese geologist named Yasutaka Ikeda had argued that the nation should expect a magnitude 9.0 in the near future—with catastrophic consequences, because Japan’s famous earthquake-and-tsunami preparedness, including the height of its sea walls, was based on incorrect science. The presentation was met with polite applause and thereafter largely ignored. Now, Goldfinger realized as the shaking hit the four-minute mark, the planet was proving the Japanese Cassandra right.

For a moment, that was pretty cool: a real-time revolution in earthquake science. Almost immediately, though, it became extremely uncool, because Goldfinger and every other seismologist standing outside in Kashiwa knew what was coming. One of them pulled out a cell phone and started streaming videos from the Japanese broadcasting station NHK, shot by helicopters that had flown out to sea soon after the shaking started. Thirty minutes after Goldfinger first stepped outside, he watched the tsunami roll in, in real time, on a two-inch screen.

In the end, the magnitude-9.0 Tohoku earthquake and subsequent tsunami killed more than eighteen thousand people, devastated northeast Japan, triggered the meltdown at the Fukushima power plant, and cost an estimated two hundred and twenty billion dollars. The shaking earlier in the week turned out to be the foreshocks of the largest earthquake in the nation’s recorded history. But for Chris Goldfinger, a paleoseismologist at Oregon State University and one of the world’s leading experts on a little-known fault line, the main quake was itself a kind of foreshock: a preview of another earthquake still to come.

Most people in the United States know just one fault line by name: the San Andreas, which runs nearly the length of California and is perpetually rumored to be on the verge of unleashing “the big one.” That rumor is misleading, no matter what the San Andreas ever does. Every fault line has an upper limit to its potency, determined by its length and width, and by how far it can slip. For the San Andreas, one of the most extensively studied and best understood fault lines in the world, that upper limit is roughly an 8.2—a powerful earthquake, but, because the Richter scale is logarithmic, only six per cent as strong as the 2011 event in Japan.

Just north of the San Andreas, however, lies another fault line. Known as the Cascadia subduction zone, it runs for seven hundred miles off the coast of the Pacific Northwest, beginning near Cape Mendocino, California, continuing along Oregon and Washington, and terminating around Vancouver Island, Canada. The “Cascadia” part of its name comes from the Cascade Range, a chain of volcanic mountains that follow the same course a hundred or so miles inland. The “subduction zone” part refers to a region of the planet where one tectonic plate is sliding underneath (subducting) another. Tectonic plates are those slabs of mantle and crust that, in their epochs-long drift, rearrange the earth’s continents and oceans. Most of the time, their movement is slow, harmless, and all but undetectable. Occasionally, at the borders where they meet, it is not.

Take your hands and hold them palms down, middle fingertips touching. Your right hand represents the North American tectonic plate, which bears on its back, among other things, our entire continent, from One World Trade Center to the Space Needle, in Seattle. Your left hand represents an oceanic plate called Juan de Fuca, ninety thousand square miles in size. The place where they meet is the Cascadia subduction zone. Now slide your left hand under your right one. That is what the Juan de Fuca plate is doing: slipping steadily beneath North America. When you try it, your right hand will slide up your left arm, as if you were pushing up your sleeve. That is what North America is not doing. It is stuck, wedged tight against the surface of the other plate.

Without moving your hands, curl your right knuckles up, so that they point toward the ceiling. Under pressure from Juan de Fuca, the stuck edge of North America is bulging upward and compressing eastward, at the rate of, respectively, three to four millimetres and thirty to forty millimetres a year. It can do so for quite some time, because, as continent stuff goes, it is young, made of rock that is still relatively elastic. (Rocks, like us, get stiffer as they age.) But it cannot do so indefinitely. There is a backstop—the craton, that ancient unbudgeable mass at the center of the continent—and, sooner or later, North America will rebound like a spring. If, on that occasion, only the southern part of the Cascadia subduction zone gives way—your first two fingers, say—the magnitude of the resulting quake will be somewhere between 8.0 and 8.6. That’s the big one. If the entire zone gives way at once, an event that seismologists call a full-margin rupture, the magnitude will be somewhere between 8.7 and 9.2. That’s the very big one.

Flick your right fingers outward, forcefully, so that your hand flattens back down again. When the next very big earthquake hits, the northwest edge of the continent, from California to Canada and the continental shelf to the Cascades, will drop by as much as six feet and rebound thirty to a hundred feet to the west—losing, within minutes, all the elevation and compression it has gained over centuries. Some of that shift will take place beneath the ocean, displacing a colossal quantity of seawater. (Watch what your fingertips do when you flatten your hand.) The water will surge upward into a huge hill, then promptly collapse. One side will rush west, toward Japan. The other side will rush east, in a seven-hundred-mile liquid wall that will reach the Northwest coast, on average, fifteen minutes after the earthquake begins. By the time the shaking has ceased and the tsunami has receded, the region will be unrecognizable. Kenneth Murphy, who directs FEMA’s Region X, the division responsible for Oregon, Washington, Idaho, and Alaska, says, “Our operating assumption is that everything west of Interstate 5 will be toast.”

In the Pacific Northwest, everything west of Interstate 5 covers some hundred and forty thousand square miles, including Seattle, Tacoma, Portland, Eugene, Salem (the capital city of Oregon), Olympia (the capital of Washington), and some seven million people. When the next full-margin rupture happens, that region will suffer the worst natural disaster in the history of North America. Roughly three thousand people died in San Francisco’s 1906 earthquake. Almost two thousand died in Hurricane Katrina. Almost three hundred died in Hurricane Sandy. FEMA projects that nearly thirteen thousand people will die in the Cascadia earthquake and tsunami. Another twenty-seven thousand will be injured, and the agency expects that it will need to provide shelter for a million displaced people, and food and water for another two and a half million. “This is one time that I’m hoping all the science is wrong, and it won’t happen for another thousand years,” Murphy says.

In fact, the science is robust, and one of the chief scientists behind it is Chris Goldfinger. Thanks to work done by him and his colleagues, we now know that the odds of the big Cascadia earthquake happening in the next fifty years are roughly one in three. The odds of the very big one are roughly one in ten. Even those numbers do not fully reflect the danger—or, more to the point, how unprepared the Pacific Northwest is to face it. The truly worrisome figures in this story are these: Thirty years ago, no one knew that the Cascadia subduction zone had ever produced a major earthquake. Forty-five years ago, no one even knew it existed.

In May of 1804, Meriwether Lewis and William Clark, together with their Corps of Discovery, set off from St. Louis on America’s first official cross-country expedition. Eighteen months later, they reached the Pacific Ocean and made camp near the present-day town of Astoria, Oregon. The United States was, at the time, twenty-nine years old. Canada was not yet a country. The continent’s far expanses were so unknown to its white explorers that Thomas Jefferson, who commissioned the journey, thought that the men would come across woolly mammoths. Native Americans had lived in the Northwest for millennia, but they had no written language, and the many things to which the arriving Europeans subjected them did not include seismological inquiries. The newcomers took the land they encountered at face value, and at face value it was a find: vast, cheap, temperate, fertile, and, to all appearances, remarkably benign.

A century and a half elapsed before anyone had any inkling that the Pacific Northwest was not a quiet place but a place in a long period of quiet. It took another fifty years to uncover and interpret the region’s seismic history. Geology, as even geologists will tell you, is not normally the sexiest of disciplines; it hunkers down with earthly stuff while the glory accrues to the human and the cosmic—to genetics, neuroscience, physics. But, sooner or later, every field has its field day, and the discovery of the Cascadia subduction zone stands as one of the greatest scientific detective stories of our time.

The first clue came from geography. Almost all of the world’s most powerful earthquakes occur in the Ring of Fire, the volcanically and seismically volatile swath of the Pacific that runs from New Zealand up through Indonesia and Japan, across the ocean to Alaska, and down the west coast of the Americas to Chile. Japan, 2011, magnitude 9.0; Indonesia, 2004, magnitude 9.1; Alaska, 1964, magnitude 9.2; Chile, 1960, magnitude 9.5—not until the late nineteen-sixties, with the rise of the theory of plate tectonics, could geologists explain this pattern. The Ring of Fire, it turns out, is really a ring of subduction zones. Nearly all the earthquakes in the region are caused by continental plates getting stuck on oceanic plates—as North America is stuck on Juan de Fuca—and then getting abruptly unstuck. And nearly all the volcanoes are caused by the oceanic plates sliding deep beneath the continental ones, eventually reaching temperatures and pressures so extreme that they melt the rock above them.

The Pacific Northwest sits squarely within the Ring of Fire. Off its coast, an oceanic plate is slipping beneath a continental one. Inland, the Cascade volcanoes mark the line where, far below, the Juan de Fuca plate is heating up and melting everything above it. In other words, the Cascadia subduction zone has, as Goldfinger put it, “all the right anatomical parts.” Yet not once in recorded history has it caused a major earthquake—or, for that matter, any quake to speak of. By contrast, other subduction zones produce major earthquakes occasionally and minor ones all the time: magnitude 5.0, magnitude 4.0, magnitude why are the neighbors moving their sofa at midnight. You can scarcely spend a week in Japan without feeling this sort of earthquake. You can spend a lifetime in many parts of the Northwest—several, in fact, if you had them to spend—and not feel so much as a quiver. The question facing geologists in the nineteen-seventies was whether the Cascadia subduction zone had ever broken its eerie silence…

Source: http://www.newyorker.com/magazine/2015/07/20/the-really-big-one

Posted in: In The News

Leave a Comment (0) →
Page 7 of 17 «...56789...»