2/28/2001 Nisqually, Washington Earthquake

Updated 3/2/2001

The quake occurred at 18:55 GMT (10:55 AM Pacific Standard Time). The magnitude was 6.8. The epicenter was between Tacoma and Olympia, Washington, about 10 miles northeast of Olympia. The focus of the quake was 30 miles deep. It was felt strongly in Portland and Vancouver, British Columbia. There were also reports that it was felt in San Francisco and Salt Lake City.

320 people were injured, 4 seriously. Damage estimates are over $2 billion. There have been considerably reports of damage, especially in Olympia near the epicenter of the quake. There have been many buildings there suffering structural damage. There is a large crack in the dome of the State Capitol Building and serious damage to other state office buildings. The legislature is right in the middle of its 105 day session. Both the Governor, the legislature and the state Supreme Court have had to relocate due to serious damage to their buildings. The Governor's Mansion is uninhabitable. Governor Locke's 2 year old son just missed being hit by a television that fell over in the Governor's Mansion. Some streets and sidewalks were badly buckled. There were also cracks in the ground up to several inches wide. Seattle skyscrapers swayed violently but apparently not dangerously. Lots of windows were broken and many buildings in downtown Seattle suffered a lot of damage, especially in the historic Pioneer Square district. In many places bricks fell from building facades. Some parked cars were covered with debris. Harborview Medical Center in Seattle closed one wing and evacuated patients. About 30 people were stranded for a couple of hours in the Space Needle while the elevators were checked. Some buildings were evacuated and Sea-Tac airport was closed for 4 or 5 hours. There was considerable damage to the Control Tower, with many of the windows broken. The Air Traffic controllers were temporarily relocated to vans next to the runway. The Portland airport was also closed. Seattle Ferry traffic was disrupted while the Seattle dock was evaluated. Passengers were stranded for a few hours on ferries that happened to be on the water at the time. Some highway bridges, including the Alaskan Way Viaduct, an elevated freeway along Seattle's waterfront were closed while crews checked for damage. Landslides closed some highways in the Cascades as well as Highway 101 north of Olympia. 100,000 people lost power but most of it was restored by the end of the day. Most of the damage was in the Olympia and Seattle areas, although there was isolated damage further away. The Peninsula College Little Theater in Port Angeles was closed due to damage and one historic office building in downtown Port Townsend had several cracks in its facade. A middle school gym in Port Townsend may also have suffered structural damage.

School children throughout the area followed instructions from their earthquake drills and ducked under their desks when their teachers told them, "We are having an earthquake. Duck under your desks and stay quiet so we can hear." Most schools were undamaged and the school day continued. Some parents did pick up their children early though.

Immediately after the quake there were large crowds of people milling around in the streets of Seattle, Olympia and as far away as Portland. Many people were alarmed by the buildings swaying in the quake and ran out into the street. In general, downtown streets are the least safe place to be during and immediately after an earthquake. The most common damage is broken windows and collapse of building facades. Both of these will shower the streets below with debris. Even when buildings do collapse they often fall into the streets. (In the Indian earthquake in January 350 schoolchildren were buried under a collapsed building facade as they marched down the street in a parade.) If there had been aftershocks to this quake, it could have brought down more debris onto the crowds below. The congestion may also have interfered a bit with emergency response. Many people were sent home early leading to considerable traffic congestion throughout the day.

This quake was similar to the quakes in Seattle in 1939 and on 4/13/1949 and 4/29/1965. The 1949 7.1 quake released 3 times as much energy as this quake. The relatively deep focus of the earthquake tended to lessen the damage since it put the focus further from the surface. The relatively deep focus also spread out the effects over a large area. The quake was caused by tensional faulting in the Juan de Fuca plate, which is subducting under the North American Plate in this area. The plate is under strain as it is bent while going under the North American Plate.

The Seattle fault is a shallower fault in the North American Plate that is also thought to be a danger for an earthquake that could cause considerably more damage. The prospects for an earthquake on the Seattle fault are not thought to be affected by this quake. The prospects for a major subduction quake off the Pacific Coast are probably not affected either. A major subduction quake could have a magnitude of 8-9 causing major damage over a large area as well as a possible tsunami. (See the Plate Tectonics page for more information on these processes.)

This quake was rated as moderate. There are several quakes this large every year throughout the world. Damage from a quake of this size depends largely on how near it is to population centers and the types of buildings in the area. In an area with unreinforced masonry buildings and no building codes, a quake like this could cause hundreds, even thousands of casualties. In a relatively unpopulated area, it could cause very little damage. This quake was in a major urban area, so it affected a lot of people, but an area that was aware of earthquake risks and has had building codes in place that require quake safe building methods. Many, but not all, older buildings have been retrofitted to improve their resistance to earthquakes. This quake can also be contrasted to the 1994 Northridge earthquake, which had a 6.7 magnitude, similar to this one, but with a shallower 11 mile deep focus, That quake caused a lot more damage and killed 72 people.

See also the following news stories:

2/13/2001 El Salvador Earthquake

Updated 2/20/2001

At 7:22 AM local time (1422 GMT) 2/13/01 an earthquake measuring 6.6 Magnitude with an epicenter 15 miles from San Salvador. The death toll is over 283 with a combined total of 1,200 dead from both recent earthquakes. Another 100,000 people were made homeless from this quake. One million people are now homeless. Damage from this quake tended to be in areas that suffered less damage in the larger January earthquake. Aftershocks from both quakes have people in a state of panic. There have been landslides and collapsed buildings. Clouds of dust billowed up from the volcano outside of San Salvador but there was no volcanic activity associated with the quake. Power and telephone service were interrupted for a while and the airport was briefly closed to check for damage. Landslides have cut off whole communities. Helicopters and heavy machinery was used to clear the debris.

Relief services in El Salvador are already stretched and thousands are still homeless from the last quake. This will make their job more difficult but President Flores called on people to pull together once more to meet the emergency. UN agencies providing relief are coming under strain from the two quakes in El Salvador and the huge Indian quake, all of which occurred in a span of a few weeks. International aid is slowing down and authorities are worried about "donor fatigue" from this string of disasters. Although this quake was smaller than either the Indian quake or January's quake, it still ranks as a major disaster in its own right. El Salvador's economy has been crippled and a large proportion of the population is unable to provide for their own needs. It will be a long time before the jobs and housing can be restored. There are concerns about sanitation and the water supply as well as the spread of disease. El Salvador was still recovering from Hurricane Mitch 3 years ago when the quakes struck.

Geologically, this quake is not considered an aftershock of January's because its epicenter was different. January's quake was a deep focus quake located in the Cocos Plate as it is subducted or pulled under the Caribbean Plate. The February quake had a shallow focus in the Caribbean Plate. The quakes may be related since they both represent the interaction of the same two plates. Similar sequences of quakes have been studied elsewhere in recent years. However, these quakes are totally unrelated to the recent earthquake in India, which involved completely different plates almost halfway around the world. (See the Plate Tectonics page for more information on these processes.)

See also the following news stories: