Earthquake News

Puget Sound's infrastructure, both buildings and social systems, should help it fare well in the face of the earthquake risk it faces in the next decades. But these guest columnists, board members of the Cascadia Region Earthquake Workgroup, urge the region not to be complacent.

By Andre Le Duc, John D. Schelling and Cale Ash

Special to The Times

 
Lessons for the Northwest

The Cascadia Region Earthquake Workgroup and Pacific Northwest Seismic Network will host a public discussion of the impacts and responses to the Haitian and Chilean earthquakes and the lessons for the Pacific Northwest from 4 to 6 p.m., March 23, at the University of Washington, Johnson Hall, Room 102. DO we have the same earthquake risks as Haiti? As Chile?

One just has to look at our majestic surroundings to realize that we also are being shaped by a comparable richness of tectonic processes. Like Haiti, many shallow faults similarly located close to our own urban centers are capable of producing powerful earthquakes. These include the Seattle, Tacoma, South Whidbey Island fault systems and others.

And, like Chile, off our coast there is the possibility of a huge megathrust earthquake on the Cascadia subduction zone — the interface between the Juan de Fuca and North American plates, which extends from Cape Mendocino in Northern California to the northern tip of Vancouver Island.

The risk earthquakes pose depends not only on natural events, but also on the vulnerability of our environment and how we prepare and respond. For reasons we are all too aware of now, Haiti's built and social structures demonstrably lacked the resilience needed to survive the shaking, despite the fact the earthquake risk was documented and the vulnerability of many of the country's systems understood.

On the other hand, Chile has a long history of living with, preparing for and responding to earthquakes. This is evident in the fact that although the Chilean earthquake released about 500 times the energy of Haiti's, their buildings have fared much better — a remarkable testimony to the efficacy of adhering to building codes designed to keep structures standing after a strong earthquake.

In the Northwest, we should take comfort in knowing we have taken actions to reduce our own vulnerability. Most buildings are built to modern codes that have proven to result in safer structures. We have redundant systems and our preparations for other disasters will help us recover from earthquakes.

However, critical aspects of our transportation infrastructure, including the Highway 520 floating bridge and the Alaskan Way Viaduct and sea wall, are vulnerable to earthquake shaking. Other critical lifelines such as ports and pipelines are also vulnerable and their failures would hinder relief and recovery efforts, potentially with a long-term economic impact. Understanding these risks is important, and mitigating them represents a clear path toward improving our resiliency.

We cannot be complacent. We have a threat and a real risk. Collectively, all the faults in the region give us a 7 percent chance of a experiencing a Haiti-style earthquake in a 50-year time window and the chance of a Chile-like earthquake along our subduction zone is slightly greater — very hefty likelihoods in most of our lifetimes.

While we have fared well in the moderate and large deep earthquakes that have occurred in the last 70 years, the largest ones (in 1949, 1965, and 2001) were different from the earthquakes that struck Haiti and Chile and that we can expect in Puget Sound. The significantly greater depths of these past events put extra distance between the earthquake and us, allowing destructive energy to dissipate before reaching the surface where we live.

Residents of Puget Sound also have not experienced the repeated shaking from aftershock activity that accompanies shallow and megathrust earthquakes. As in Haiti and Chile, we will have to respond and recover over months and years while our structures and psyches continue to be shaken.

Although exacerbated in Haiti by its island geography and less-resilient infrastructure, both countries experienced failures of their communications systems and consequent information vacuums and chaos immediately following and, in spots, for days after the earthquakes. We can expect the same in the Pacific Northwest, although the recovery time frame may be shorter.

Geophysicist R. Bilham writes, "In recent earthquakes, buildings have acted as weapons of mass destruction." Perhaps the clearest lesson of the Haitian and Chilean earthquakes is that we must support the adoption and enforcement of building codes, the funding that strengthens our infrastructure, and programs that help prepare our communities.

For more information we encourage you to visit www.crew.org. We encourage you to download the new Cascadia Region Earthquake Workgroup (CREW) Shallow Earthquake and the Cascadia Subduction Zone scenario pamphlets and begin implementing the state of Washington Emergency Management 12-step preparedness process accessible from the CREW "Home Owners" Web-site link. We all have a role in preparing our community for a natural disaster.

Andre LeDuc is executive director of the Oregon Partnership for Disaster Resilience at the University of Oregon. John Schelling is earthquake program manager for Washington State Emergency Management. Cale Ash is a project engineer at Degenkolb Engineers. Le Duc is president is of the Cascadia Region Earthquake Workgroup; the others are board members.
 

A devastating earthquake struck Chile early Saturday, toppling homes, collapsing bridges and plunging trucks into the fractured earth. A tsunami set off by the magnitude-8.8 quake threatened every nation around the Pacific Ocean - roughly a quarter of the globe.

By ROBERTO CANDIA and EVA VERGARA

Associated Press Writer

8.8-magnitude earthquake hits Chile
Chile quake spawns tsunami, threatens Pacific Rim
Hawaii under tsunami warning
California under tsunami advisory
TALCA, Chile —

A devastating earthquake struck Chile early Saturday, toppling homes, collapsing bridges and plunging trucks into the fractured earth. A tsunami set off by the magnitude-8.8 quake threatened every nation around the Pacific Ocean - roughly a quarter of the globe.

Interior Minister Edmundo Perez Yoma said the most powerful quake to hit the country in a half-century killed at least 82 people, but the death toll was rising quickly.

In the town of Talca, just 65 miles (105 kilometers) from the epicenter, Associated Press journalist Roberto Candia said it felt as if a giant had grabbed him and shaken him.

The town's historic center, filled with buildings of adobe mud and straw, largely collapsed, though most of those were businesses that were not inhabited during the 3:34 a.m. (1:34 a.m. EST, 0634 GMT) quake. Neighbors pulled at least five people from the rubble while emergency workers, themselves disoriented, asked for information from reporters.

Many roads were destroyed, and electricity, water and phone lines were cut to many areas - meaning there was no word of death or damage from many outlying areas.

In the Chilean capital of Santiago, 200 miles (325 kilometers) northeast of the epicenter, a car dangled from a collapsed overpass, the national Fine Arts Museum was badly damaged and an apartment building's two-story parking lot pancaked, smashing about 50 cars whose alarms rang incessantly.

Experts warned that a tsunami could strike anywhere in the Pacific, and Hawaii could face its largest waves since 1964 starting at 11:19 a.m. (4:19 p.m. EST, 2119 GMT), according to Charles McCreery, director of the Pacific Tsunami Warning Center.

Tsunami waves were likely to hit Asian, Australian and New Zealand shores within 24 hours of the earthquake. The U.S. West Coast and Alaska, too, were threatened.

A huge wave swept into a populated area in the Robinson Crusoe Islands, 410 miles (660 kilometers) off the Chilean coast, President Michelle Bachelet said, but there were no immediate reports of major damage.

Bachelet had no information on the number of people injured. She declared a "state of catastrophe" in central Chile.

"We have had a huge earthquake, with some aftershocks," she said from an emergency response center. She said Chile has not asked for assistance from other countries, and urged Chileans not to panic.

"The system is functioning. People should remain calm. We're doing everything we can with all the forces we have. Any information we will share immediately," she said.

 Powerful aftershocks rattled Chile's coast - 24 of them magnitude 5 or greater and one reaching magnitude 6.9 - the U.S. Geological Survey reported.

In Santiago, modern buildings are built to withstand earthquakes, but many older ones were heavily damaged, including the Nuestra Senora de la Providencia church, whose bell tower collapsed. A bridge just outside the capital also collapsed, and at least one car flipped upside down.

Several hospitals were evacuated due to earthquake damage, Bachelet said.

Santiago's airport will remain closed for at least 24 hours, airport director Eduardo del Canto said. The passenger terminal suffered major damage, he told Chilean television in a telephone interview. TV images show smashed windows, partially collapsed ceilings and pedestrian walkways destroyed.

Santiago's subway was shut as well and hundreds of buses were trapped at a terminal by a damaged bridge, Transportation and Telecommunications Minister told Chilean television. He urged Chileans to make phone calls or travel only when absolutely necessary.

Candia was visiting his wife's 92-year-old grandmother in Talca when the quake struck.

"Everything was falling - chests of drawers, everything," he said. "I was sleeping with my 8-year-old son Diego and I managed to cover his head with a pillow. It was like major turbulence on an airplane."

In Concepcion, 70 miles (115 kilometers) from the epicenter, nurses and residents pushed the injured through the streets on stretchers. Others walked around in a daze wrapped in blankets, some carrying infants in their arms.

Concepcion, Chile's second-largest city, is 60 miles (95 kilometers) from the ski town of Chillan, a gateway to Andean ski resorts that was destroyed in a 1939 earthquake.

The quake also shook buildings in Argentina's capital of Buenos Aires, 900 miles (1,400 kilometers) away on the Atlantic side of South America.

Marco Vidal, a program director for Grand Circle Travel who was traveling with a group of 34 Americans, was on the 19th floor of the Crown Plaza Santiago hotel when the quake struck.

"All the things start to fall. The lamps, everything, was going on the floor," he said. "I felt terrified."

Cynthia Iocono, from Linwood, Pennsylvania, said she first thought the quake was a train.

"But then I thought, `Oh, there's no train here.' And then the lamps flew off the dresser and my TV flew off onto the floor and crashed."

The quake struck after concert-goers had left South America's leading music festival in the coastal city of Vina del Mar, but it caught partiers leaving a disco.

"It was very bad. People were screaming. Some people were running, others appeared paralyzed. I was one of them," Julio Alvarez told Radio Cooperativa.

The Pacific Tsunami Warning Center called for "urgent action to protect lives and property" in Hawaii, which is among 53 nations and territories subject to tsunami warnings.

"Sea level readings indicate a tsunami was generated. It may have been destructive along coasts near the earthquake epicenter and could also be a threat to more distant coasts," the warning center said. It did not expect a tsunami along the west of the U.S. or Canada.

The largest earthquake ever recorded struck the same area of Chile on May 22, 1960. The magnitude-9.5 quake killed 1,655 people and left 2 million homeless. The tsunami that it caused killed people in Hawaii, Japan and the Philippines and caused damage to the west coast of the United States.

---

Eva Vergara reported from Santiago, Chile. Associated Press Television News cameraman Mauricio Cuevas in Santiago and AP writer Sandy Kozel in Washington contributed to this story.

New studies suggest that a Cascadia megaquake could occur within 50 miles of Seattle — much closer than previously thought.

By Sandi Doughton

Seattle Times science reporter

To figure out where the fault will snap, Melbourne and co-author James Chapman analyzed data from 15 "silent earthquakes" that occurred beneath the Olympic Peninsula.

Scientists believe the nearly imperceptible rumbles of these silent quakes reflect deep slippage on the fault, in a zone where heat and pressure render the rocks plastic.

But that deep slip increases pressure on the danger zone: The locked portion of the fault closer to the surface.

"Eventually the fault will rupture and unload that spring," Melbourne said.

The key to knowing where the rupture will occur is knowing where the plates are locked.

Early analyses, based on a basic understanding of temperature and rock behavior, put the locked zone just off the Washington coast.

"You try to calculate where the rocks slide freely and where the rocks will lock," said John Vidale, head of the Pacific Northwest Seismic Network at the University of Washington. "It was really kind of a wild guess that we had before."

Melbourne and Chapman took a more systematic approach, using the "silent quake" data to calculate strain on the fault. They then looked at data from a network of GPS receivers across the Northwest that show how different parts of the region are being differentially squeezed and shoved by the slow-motion force of the colliding geologic plates: Pacific Beach on the Washington coast moves northeast about 0.8 inches a year, while Whidbey Island shifts a scant 0.2 inches a year.

"What we measure is where the crust is deformed above the fault, and from that we can back out where the fault itself is locked," Melbourne said.

The best explanation is that the locked portion of the fault actually extends well beneath the Olympic Peninsula, he said.

The UW's Vidale and his colleagues reached the same conclusion from seismic studies that show the silent quakes originate in the same area.

But Herb Dragert, at the Geological Society of Canada's Sidney, B.C., branch, says analysis of a similar fault in Japan suggests there might be a kind of transition zone where the plates are not fully locked, and therefore not as dangerous.

"The question is still open," Dragert said.

No matter where the fault breaks, Heaton and his student Jing Yang concluded the damage in Seattle would be severe. The ground would shake violently for three to five minutes. Unlike in a Seattle Fault quake, wooden houses and modern, low-rise buildings would be relatively unscathed in a subduction zone event.

But many high-rises built before 1994 could be in serious trouble, largely because of welds used in place of rivets in their steel frames.

"These giant Cascadia earthquakes are certainly very different from anything that was used to formulate the codes," Heaton said.

"What we need to do is follow up on these studies and try to come up with a more rational way to decide what's the appropriate design for our buildings."

Study: Fault line under Seattle bigger than thought

Watch the story

SEATTLE -- The fault line under Seattle could be bigger than anyone thought, according to new research conducted by a University of Washington graduate student.

Beth Martin found evidence that could mean quakes along the fault line could be larger, and even trigger a tsunami.

The Nisqually earthquake that rocked the Northwest eight years ago was a 6.8 magnitude.

The quake, centered deep in the Earth, caused a lot of shaking and some damage.

But the ground didn't rise up like it did 1,000 years ago. That's when scientists believe a 7- to 7.5-magnitude earthquake hit the more shallow Seattle fault zone that runs from Sammamish, through Seattle and out toward Bremerton.

Scientists believe some areas rose 18 feet during the quake, that the southwest tip of Bainbridge Island rose out of the Puget Sound, and so did much of Alki Point in West Seattle, which is now full of homes.

The quake also generated a tsunami - a wave possibly six feet high - when it hit Elliott Bay in Shoreline.

And now Martin says she's gathered evidence that the Seattle fault zone could be much bigger than we think, and a quake could spread damage much further west.

Martin's evidence comes from, of all things, clams. They're carbon-dated back to that big quake and found in soil samples she took in the tide lands near Gorst, much further west from where scientists believed the fault ends.

"So somehow this area went from a tide flat with clams in it to a cedar forest. So that's my evidence that everything went up," she said, pointing to the soil sample.

If the shallow Seattle fault is longer, scientists say another quake could do more damage and trigger a bigger tsunami.

Scientists say they aren't sure exactly where the fault line begins and ends.

And in case you were wondering, yes, an earthquake underneath Lake Washington could generate a tsunami.

Scary stuff.  Liquefying soil, collapsing roadways, utility outages, highway collapse.  Replacing the Alaskan Way Viaduct is above our pay grade, but this video provides a sobering picture of what kind of damage a strong earthquake could produce locally.

WSDOT video

The cracking of the Juan de Fuca plate, deep beneath the Olympic Peninsula, rattled the Seattle and Puget Sound area at 5:25 a.m. today but there were no immediate reports of damage from the 4.6 magnitude earthquake.

By Sara Jean Green

Seattle Times staff reporter

Related

The cracking of the Juan de Fuca plate, deep beneath the Olympic Peninsula, rattled the Seattle and Puget Sound area at 5:25 a.m. today but there were no immediate reports of damage from the 4.6 magnitude earthquake.

"It was significant but not huge," said Bill Steele, coordinator of the Pacific Northwest Seismic Network's Seismology Lab, located at the University of Washington. "We've had no reports of damage and we don't expect any."

By 7 a.m., seismologists had received 900 reports from people who felt the quake, from the Olympic Peninsula to the Greater Seattle-Everett area, Steele said. The quake occurred 58 kilometers below the surface — and far below the earth's crust, which means there's little chance that anyone will feel tiny aftershocks, he said.

"It was probably the cracking of the Juan de Fuca plate deep beneath us. The slab is under stress and is being pulled by gravity," Steele said.

The earthquake was centered east of Kingston.

Steele said it occurred just north of the center of the 2001 Nisqually earthquake that registered a magnitude 6.8 and caused damage throughout the region.

Though the actual cracking of the Juan de Fuca plate lasted maybe a second this morning, followed by 10 to 20 seconds of reverberations, the quake still woke plenty of people up.

"It shook the house like something had hit the roof," said Robert Lynden, who lives on Anderson Island in Puget Sound. "It just woke us up." Other than knocking a water fountain off his deck there was no damage.

Lacey Menne says it shook her home as she was preparing to go to work at the Coastal Cafe in Kingston.

"It wasn't strong enough to make anything fall," she said. "It was like, what is that? I think it might be an earthquake. It's totally an earthquake!"

James Baird, who lives in Jefferson County near the border with Kitsap County, said he was drying clothes when he felt movement and said "Hey, this doesn't feel like my dryer shaking ... It was definitely an earthquake."

The quake caused Tye Thompson, who lives on Dexter Avenue in Seattle, to jump out of bed and lock the sliding-glass door to the balcony off his second-floor apartment.

"It was so quick — like boom-boom-boom — and I thought it was either somebody trying to move furniture or somebody trying to scale the side of my deck," said Thompson. "That was my half-awake logic."

Then he switched on the TV news: "I was like, that explains everything. I don't need to be paranoid," Thompson said with a laugh.

Friday's quake was "our biggest event" in more than a year, said John Vidale, director of the Pacific Northwest Seismic Network, which monitors seismic activity in Washington and Oregon.

"Essentially, there's an ongoing series of earthquakes at that location," Vidale said of the Juan de Fuca plate, but most of them are too small to be felt.

In downtown Seattle, people would've felt 1/1000th of a G, which is the measurement of the force of gravity, while closer to the epicenter, it would have registered about 1/400th of a G, Vidale said. A serious earthquake would be between 1/3 and ½ of a G.

The state Department of Transportation didn't find any problems in the structures they looked at this morning. The agency inspected the Alaskan Way Viaduct, the I-90 and SR 520 bridges and the approaches to those bridges. Crews also will check on structures closer to the quakes's center and throughout Kitsap, Snohomish, King and Clallam counties.

Portions of this report came from The Associated Press

Copyright © 2009 The Seattle Times Company

Visit the official USGS page for this event here.

By TINI TRAN, Associated Press Writer Sat May 24, 1:36 PM ET

YINGXIU, China - China warned Saturday that the death toll from a massive earthquake two weeks ago could take a major leap and pass 80,000, suggesting the government may be giving up hope of finding more survivors.

But rescuers rushed anyway to reach 24 coal miners who officials said were trapped in three mines by the disaster, though it was not known if the miners were alive.

"We have had the miracle in the past that a miner was found alive after being trapped underground for 21 days," Wang Dexue, the deputy chief of the government's work safety department, told a news conference in Beijing. "We are carrying out rescue work on the assumption that they are still alive. We absolutely will not give up."

Wang gave no further details of the trapped miners. China's mines are the world's deadliest, with explosions, cave-ins and floods killing nearly 3,800 people last year.

Meanwhile, U.N. Secretary-General Ban Ki-moon made a brief visit Saturday to one of the hardest-hit towns, Yingxiu — a helicopter ride that offered a rare bird's-eye views of the destruction wrought by the 7.9-magnitude quake on May 12.

The mountains in central Sichuan province showed huge tracks of naked earth from landslides. Layers of mud covered fields. Rivers churned brown. Yingxiu itself was largely piles of rubble, and the buildings left standing had caved in, giving the surreal impression that they had melted.

The State Council, China's Cabinet, said Saturday the latest confirmed death toll for the quake — China's biggest disaster in three decades — was 60,560, with 26,221 people still missing.

Premier Wen Jiabao, on a return visit to the quake zone to accompany Ban, warned the toll could go much higher.

"It may further climb to a level of 70,000, 80,000 or more," Wen said, standing amid the rubble in Yingxiu. The jump could occur as the number of missing are added to the number of dead.

About 15 minutes before Wen started talking, yet another minor aftershock rumbled.

Ban, who came to China directly from cyclone-stricken Myanmar, promised the U.N. would help with reconstruction and that it was waiting for China's assessment of what was needed.

"If we work hard, we can overcome this," Ban said, with Wen standing at his side. "The whole world stands behind you and supports you."

The secretary-general left China later Saturday and was to attend an aid donors conference in Myanmar for cyclone victims on Sunday.

About 4,800 of Yingxiu's 18,000 people were killed in the quake, a military officer told Ban during a tour. Reporters could see government workers in hooded white protective suits spraying disinfectant on the rubble.

Underscoring doubts that more survivors would be found, Wen said the government's focus had shifted from rescue to rebuilding.

"Previously our main priority was the search and rescue of affected people," Wen said. "Our priority now is to resettle the affected people and to make plans for post-quake reconstruction."

It won't be easy. The quake destroyed more than 15 million homes, Wen said. He said the government needed 900,000 tents and urged Chinese manufacturers to make 30,000 a day.

As the government grappled with the task of rebuilding — a process Sichuan Vice Governor Li Chengyun has said could take three years — it also watched for a variety of secondary disasters.

Experts searched for 15 radiation sources buried in the rubble, although they said there were no leaks or public health risk. And survivors left flood-risk areas downstream from rivers that had been dammed by landslides.

With their water pooling and the rainy season coming, the "quake lakes" could breach the earthen barriers and sweep down already fragile valleys.

Meanwhile, some 10,000 medical workers have been dispatched to prevent disease outbreaks.

"The second major challenge facing us is epidemic prevention and control," Wen said, adding that no outbreaks had been reported so far.

The premier also promised that China would continue its openness about the quake, in which the government has accepted foreign relief teams and allowed Chinese media to report in relative depth on the disaster.

"From the very beginning of the disaster relief, we put people's lives above all," Wen said, "We have adopted an open policy because we think it was not only the disaster for Chinese people, but the people of the world. Our spirit of putting people above all and our open policy will not change."

Also Saturday, eight pandas reached Beijing safely after a long journey from their damaged reserve near the quake's epicenter. The pandas will spend the next six months at the Beijing Zoo on a special Olympics visit that was planned long before the quake.

The pandas' home at the world-famous Wolong reserve was badly damaged by the quake and five staff members were killed.

The pandas have been closely watched because they seemed nervous after the earthquake, sometimes eating and sleeping less. But the pandas appeared lively after they were moved into their exhibit space at the Beijing Zoo on Saturday evening, even putting their paws on the glass separating them from the media and the public.

Last updated April 23, 2008 7:58 p.m. PT

By DONNA GORDON BLANKINSHIP
ASSOCIATED PRESS WRITER

SEATTLE -- Scientists are discussing two more ways Western Washington could shake, rattle and roll.

The U.S. Geological Survey's new seismic hazard maps, released this week, show two more earthquake faults in Western Washington: one near the Canadian border, the other east of Port Angeles.

The new maps also contain some good news for Washington residents. Scientists now estimate that potential ground motion in the Western United States is 30 percent lower than they previously thought for the kind of quakes caused by long-period seismic waves that would affect taller, multistory buildings.

Scientists developed these new estimates by using new ground-motion predicting models created after looking at shaking records from 173 global shallow crustal earthquakes to better understand what is happening in the western U.S.

They believe one of the newly added faults, called the Boulder Creek fault and located near Bellingham and the Canadian border, is capable of a magnitude-6.8 earthquake and has been active over the past several thousand years. Residents of Canada are in more danger from this fault than people who live in Washington state.

The other newly added fault, the Lake Creek-Boundary Creek fault, is east of Port Angeles along the Strait of Juan de Fuca and Olympic National Park. It is capable of producing a magnitude-7.4 earthquake and has been active over the past several thousand years.

Washington and Oregon have about 100 known faults. More than 1,000 earthquakes occur in Washington each year.

The February 2001 Nisqually earthquake, which had an epicenter northeast of Olympia, was a magnitude-6.8 quake.

On the Richter scale, every increase of one number means a tenfold increase in magnitude. Thus a reading of 7.5 reflects an earthquake 10 times stronger than one of 6.5.

An earthquake of 3.5 on the Richter scale can cause slight damage in a local area, 4 can cause moderate damage, 5 considerable damage, and 6 can be severe. A 7 reading is a "major" quake, capable of widespread heavy damage, and 8 is a "great" quake, capable of tremendous damage.

The report also contains new information that a fault south of Whidbey Island is longer than previously thought, extending through Seattle's northern suburbs at least as far Woodinville and possibly southeast to North Bend. The fault has the highest hazard level of any fault in Western Washington and could produce a magnitude-7.5 earthquake. There have been at least four quakes along this fault in the past 16,000 years.

Scientists now believe the Cascadia Subduction Zone, which runs off the shore of northern California, Oregon and Washington, is more likely to experience one great quake that will completely rupture the fault, rather than the other possibility of a series of smaller, but still major, quakes.

"The primary constraint on our Cascadia earthquake model is that great earthquakes occur on average once every 500 years," cautioned Arthur D. Frankel and Mark D. Petersen, the scientists who wrote that section of the report. That makes it difficult to make predictions concerning quakes in that zone.

The last great Cascadia rupture is believed to have occurred in January 1700, based on analysis of tsunami records in Japan, trees along the Pacific coast and a study of tsunami deposits and other geophysical data, the report said.

USGS last published nationwide hazard maps in 2002 and 1996. The new maps are being released at the same time as a national revision of the model building codes used by state and local government so that buildings, bridges, highways and utilities can resist earthquake damage.

The National Seismic Hazard Maps are a series of maps and data sets that project the ground shaking that might happen at points throughout the country.

Insurance companies use the data to set rates in some places. Engineers use the maps to forecast landslides and the stability of hillsides. Federal environmental regulators use the maps to ensure waste-treatment facilities will hold up. Emergency planners use the information to decide how to allocate money for education and preparedness.

Constantly updated by the USGS, this site shows recent earthquakes in our area.  Graphics show the magnitude of the shaking and how recently it occurred. 

You might be surprised to see how active our area is.

CASCADIA EPISODIC TREMOR AND SLIP (ETS) UNDERWAY (September 13, 2005)
Slow earthquakes affecting southern British Columbia and northern Washington have been occurring every 14 months or so over the last 10 years. The PNSN has deployed additional seismometers to record expected tremor events to gain insight into the process and into the stresses that eventually will lead to the region's next major earthquake.

SEATTLE POST-INTELLIGENCER: Seattle's readiness for disaster in doubt (Saturday, September 10, 2005)

We don't live below sea level or experience hurricanes, but Seattle -- sitting on a seismic fault believed capable of producing a massive quake -- ranks right up there with New Orleans when it comes to its risk of catastrophic natural disaster. Unfortunately, some experts say, we also share with New Orleans a tendency to delay taking some of the actions needed to reduce damage and loss of life.

SEATTLE POST-INTELLIGENCER: Denial can lead to a disaster just as easily here (Wednesday, September 7, 2005)

SEATTLE POST-INTELLIGENCER:Tsunami experts meet at UW to study disaster (Monday, June 13, 2005)

The rest of the world may give less thought these days to the Indian Ocean tsunami, but a small cadre of scientists remains fascinated, horrified and perhaps even a bit confused by the natural disaster that killed about 200,000 on Dec. 26.

Portland Oregonian: Report paints grim picture of Northwest after big quake (Wednesday May 25, 2005)

A group urges education programs and construction upgrades to help the region prepare for a catastrophe. The earthquake could be "catastrophic" and "will certainly be larger than local or regional resources can respond to," the report states. It urges that education programs teach residents and visitors how to prepare for such an earthquake; high-risk buildings be retrofitted; key buildings such as hospitals, schools and fire stations be improved to withstand the shaking; and transportation infrastructure be upgraded.

SEATTLE POST-INTELLIGENCER: Report gives fine details of potential mega-quake ( Wednesday, April 20, 2005)

On the second Tuesday in July, a massive, magnitude-9 earthquake -- much like the one that devastated Sumatra on Dec. 26 -- will be produced off the Pacific Northwest coast. But this mega-quake will be produced only in concept today at a hotel in Bellevue, by a group of scientists, engineers, planners and business leaders who want to encourage better preparation for the day when the Cascadia Subduction Fault zone erupts again.

Times Magazine 2005 Top 100: Brian Atwater -- In Search of the Great Tsunami (April 2005)

What does the scratched-up canoe that sits outside geologist Brian Atwater's Seattle home have to do with the destructive power of tsunamis? Quite a bit: it was in his canoe, paddling around the salt marshes and tidal flats of Washington State, that Atwater discovered evidence of earthquakes and giant waves of a magnitude that seemed, to many, inconceivable--until late last year, when a tsunami of similar power tore across the Indian Ocean, killing more than 200,000.

SMITHSONIAN MAGAZINE: Future Shocks--Modern science, ancient catastrophes and the endless quest to predict earthquakes (March 2005)
Brian Atwater paddled a battered aluminum canoe up the Copalis River, pushed along by a rising Pacific tide. The river wound through wide salt marshes fringed with conifers growing on high ground. The scene, softened by gray winter light and drizzle, was so quiet one could hear the whisper of surf a mile away. But then Atwater rounded a bend, and a vision of sudden, violent destruction appeared before him: stranded in the middle of a marsh were dozens of towering western red cedars, weathered like old bones, their gnarly, hollow trunks wide enough to crawl into. "The ghost forest," Atwater said, pulling his paddle from the water. "Earthquake victims."

KING COUNTY JOURNAL: Quake scenario paints scary scene (March 1, 2005)
It's called the Seattle Fault but a more apt name might be the I-90 Fault since it runs more or less alongside the interstate from just north of Issaquah, 14 miles to Seattle's Harbor Island. By whatever name, however, when the next major earthquake is triggered on the fault, the consequences will be devastating, according to a scenario developed by seismologists, geologists, engineers, emergency managers, planners and others.

SEATTLE TIMES: Experts outline steps to cut quake damage (Tuesday, March 1, 2005)

There's no denying a major earthquake on the Seattle Fault would be nasty. But there are many ways to prevent a bad situation from being even worse, said several participants at an earthquake workshop yesterday in Bellevue — a scant mile from where the fault slices through the city of 117,000.

SEATTLE POST-INTELLIGENCER: Experts predict 1,600 could die in quake (Tuesday, March 1, 2005)

Puget Sound area still unprepared for such a disaster. Four years to the day after the Nisqually Quake, experts at a conference yesterday warned that most Puget Sound-area communities still are not even close to being prepared for a major quake.

SEATTLE TIMES: Pinpointing devastation if Seattle Fault ruptures (Sunday, February 20, 2005) The scenario, which will be unveiled in a daylong workshop in Bellevue on Feb. 28, uses a sophisticated computer model and the collective expertise of dozens of local engineers, scientists and emergency managers to forecast the devastation that would be wrought by a magnitude 6.7 earthquake on the Seattle Fault.

SEATTLE POST-INTELLIGENCER: 'Tsunami on its way, gonna happen any day' (Thursday, February 10, 2005)

SEATTLE POST-INTELLIGENCER: New findings super-size our tsunami threat (Monday, February 7, 2005)

NEWS RELEASE-Old Japanese Documents Confirm Warnings of Future North American Earthquakes (November 20, 2003)
Writing this week in the American Geophysical Union's Journal of Geophysical Research, scientists from Japan, Canada and the United States summarize old reports of flooding and damage by a tsunami in 1700 on the Pacific coast of Japan. With the aid of computer simulations, they conclude this tsunami required a North American earthquake close to magnitude 9. Such an earthquake, in a few minutes, would release about as much energy as the United States now consumes in a month.

The News Tribune - Tacoma, WA: Tacoma Fault poses a threat (November 3, 2003)
Researchers Sunday unveiled their first firm evidence that a Tacoma fault line exists and that it's larger than they suspected.

Now, the challenge is to home in on where the Tacoma Fault runs. In the winter, researchers will study the White River Fault near Enumclaw and whether it connects with the Tacoma Fault, Brian Sherrod of the U.S. Geological Survey told an international conference of geoscientists in Seattle.
The Tacoma Fault "adds yet another reminder that we live in an area that's prone to big earthquakes," said Sherrod, who is also affiliated with the University of Washington. "It adds another piece of the tectonic puzzle."

Seattle Post-Intelligencer: Newly found fault shakes up beliefs about regional quakes (September 10, 2003)
Using everything from a highly sophisticated airborne laser to a ground-based backhoe, scientists have found a new fault on Bainbridge Island that challenges some of their basic beliefs about the seismic time bomb that runs beneath Seattle.
"This means we need to fundamentally change our view of the geometry of the Seattle Fault," said Brian Sherrod, a field geologist with the U.S. Geological Survey. What the scientists found on Bainbridge was evidence of perhaps two prehistoric earthquakes that sent up massive blocks of land -- in the wrong direction.

Seattle Times: Mysterious 1872 quake yields clues for future (July 22, 2003)

Alison Bickerstaff. Ruth Ludwin and fellow researchers at the University of Washington, including three U.S. Geological Survey scientists, say a deeper knowledge of the largest crustal earthquake in Washington state's history will help to define the risks other quakes pose east of the Cascades.

The Oregonian: Science - Landslide Sleuths (May 15,2002)

Richard Hill, The Oregonian science writer, reports on evidence that the great Bonneville landslide in the Columbia River basin, resulted from shaking during the Great Cascadia earthquake in 1700.

LIDAR Data Online March 3, 2002
LIDAR (LIght Distance And Ranging, also known as Airborne Laser Swath Mapping or ALSM) is a relatively new technology that employs an airborne scanning laser rangefinder to produce accurate topographic surveys of unparalleled detail.