More devastating than the Good Friday Earthquake itself, the seismic sea waves or tsunamis, that followed caused the major loss of life and property in Alaska.
Tsunamis are generated by the sudden upward movement of the seafloor along the rupturing fault. These waves can travel thousands of miles and can strike low-lying coastal areas hours after an earthquake with violent force. In the Good Friday Earthquake, some areas like Anchorage were barely affected by tsunamis. Other coastal communities with different topography, like Chenega, Kodiak, Seward and Valdez suffered complete ruin. Sharing in grim destructive power are waves generated by submarine landslides along coastal areas where huge volumes of water are rapidly displaced by soil debris. These waves occur during or immediately after an earthquake and can be 30 to 50 feet in height, as high as a large tsunami wave
A Tale of Two Cities
Valdez Valdez was nestled at the head of a scenic fjord in Prince William Sound. A thriving city of 1200 people, Valdez's economy was based on fishing, shipping and tourism. When the Good Friday Earthquake struck at 5:36 p.m., the entire city began violently heaving, and huge fissures formed in the earth spewing mud, water and sewage 20 feet into the air.
Twenty-eight people were on the dock, watching the unloading of the SS Chena, a 400 foot Liberty Ship. As the quake reached full force, it triggered a submarine landslide under the harbor area, which generated a 40 foot wave which instantaneously destroyed the harbor, the docks, the canneries, and all the people on the dock. The SS Chena bottomed out three times, rolling in pitching so violently that three seamen were killed. When the huge wave retreated, it threw the SS Chena out to sea, relatively undamaged. Successive tsunamis completed the destruction of Valdez. After the earthquake, the city decided to move to a seismically safer area rather than rebuild. Today Valdez sits four miles northwest of the original site.
Seward A fortunate town, Seward was one of the few ice free ports in Southcentral Alaska, and had an active economy in fishing and industry all year. Everything changed at 5:36 p.m., March 27, 1964. Forty-five seconds after the earthquake started shaking, huge slices of the Seward waterfront and harbor slid into the bay. The Standard Oil dock facility ruptured, spewing fuel everywhere. As the Standard Oil tanks overturned, they exploded and caught fire. A wall of water 30 feet high, generated by a submarine landslide, and covered in burning oil, swallowed the remaining harbor and dock area. Forty oil-filled railroad tank cars exploded in a chain reaction. As the first wave subsided, people made their way to high ground, fearing tsunamis. Twenty-five minutes after the earthquake, the first tsunami hit Seward with 40 foot waves moving 100 mph. The waves were still ablaze with burning oil. The last tsunami left the town 10 hours later leaving 13 people dead and Seward totally devastated.
Comments 0 comments