The One Before "The Big One"- Nisqually Earthquake 2001

 On February 28th, 2001 western Washington had the largest earthquake in over 40 years. My mom was 2 months pregnant with me with so *technically* I was there. Even if I don’t remember it, both my parents do. They said it felt like they were hallucinating. My mom was vacuuming when it started and she said it looked like the tile floor was undulating and that it was a super weird sensation. We can see a major elevated bridge (I-5 Ship Canal Bridge) from my house and she remembers that the bridge was bouncing with the earthquake. She said that luckily nothing broke and they were able to ride it out in the middle of the street. 

Damage in downtown Seattle

1-5 Ship Canal Bridge

The earthquake was a moment magnitude 6.8 and a maximum Mercalli intensity of VIII or severe. It resulted from a fault more than 35 miles under the Nisqually Delta, resulting in the quake being named the Nisqually earthquake. The epicenter was in southern Puget Sound and was felt in Washington, Oregon, Idaho, and British Columbia. The closest large city was the capital of Washington, Olympia, which saw most of the damage. The earthquake lasted almost a full minute. Despite causing severe damage, larger earthquakes are expected from the Cascadia Subduction Zone in the future.

Structural damage to the face of a building in Seattle

Luckily there were no direct casualties, but 400 people were injured. One person died from a heart attack after the quake. The property damage was approximated between $1-4 billion. The majority of the damage was close to the epicenter or in buildings that were unreinforced and made of concrete or masonry. In Seattle the neighborhoods of First Hill, Pioneer Square and SoDo saw the most amount of damage. These areas of the cities are historic and most are made using bricks. In some suburbs debris from landslides trapped people inside. The debris from the landslide filled a river channel resulting in flooding. Power outages that resulted from the earthquake was another issue caused by the earthquake. The air traffic control tower at Seattle-Tacoma International Airport saw a significant amount of damage and had to be replaced. Little damage was seen in British Columbia. Many bridges had to temporarily close in order to get inspected. Specifically the Alaskan Way Viaduct, a major elevated highway that connects the two ends of Seattle, was damaged. It was ultimately torn down due to the damage and an underground tunnel was built to replace it. 

Property damage was between $1-4 billion. 

This earthquake was a major wakeup call for the region and reminded residents how earthquake prone the subduction zone truly is. Since the earthquake major retrofitting has taken place to reinforce buildings and bridges. Earthquake alert systems are now in place to warn residents about earthquakes right on their phones. Even if it only warns people seconds before it can still prepare people to avoid places in their environment that could cause injury.

Sources:

https://www.king5.com/article/news/history/nisqually-earthquake/20th-anniversary-nisqually-earthquake-western-washington/281-df8b4d26-c842-45dc-a7c9-406167d06fc7

https://pubs.geoscienceworld.org/ssa/bssa/article/94/2/363/146915/Fault-Parameters-of-the-Nisqually-Earthquake?casa_token=U237VL5fpVcAAAAA:_WysW6v5ReI7woBuI4qdrgYH8K_2CcKD253RavCOnBZobtW3gFaIQFWROhcc1KokEw2bnV8V