Earthquakes VI

Earthquakes can be potentially one of the most devastating natural disasters. In September, of 2000, FEMA released a study estimating annual earthquake losses in the United States to be $4.4 billion; with California, Oregon and Washington accounting for $3.3 billion. The largest earthquake in the United States history was the 1964 Alaska Earthquake, at 9.2 on the Richter Scale, caused $311 million in damage and killed 115 people. Nationwide, 39 states are at risk for a devastating earthquake but some states are more vulnerable than others. Earthquake mitigation, ranging from improved building codes to homeowner education to upgrading bridges and other lifelines, has had tremendous success in reducing earthquake damage. One effective earthquake mitigation is improved building codes and standards. As a result of the Northridge Earthquake of 1994, in southern California, for example, the greatest physical loss was sustained by older buildings. However, according to a recent report on hazard mitigation, those structures built after 1976 performed significantly better than those built prior to 1976. By far the most serious earthquake damage is structural, which can be hidden or apparent, and can be cosmetic or can compromise the structural integrity of the building. Non-structural building damage might include impacts to sprinklers, pipes and drop or suspended ceilings. 

Division of Homeland Security and Emergency Management. (2010) Earthquake Mitigation. Retrieved April 2 from http://www.ak-prepared.com/plans/mitigation/equake.htm

NESEC. (2010) Earthquakes. Retrieved April 2 from http://www.nesec.org/hazards/earthquakes.cfm

FEMA. (2002) Earthquake Mitigation Handbook. Retrieved April 2 from http://www.conservationtech.com/FEMA-WEB/FEMA-subweb-EQ/index.htm

Earthquakes V

The 1964 Alaska earthquake, also known as the Good Friday Earthquake, began at 5:36 P.M. AST on Good Friday, March 27, 1964. Across south-central Alaska, ground fissures, collapsing buildings, and tsunamis and the resulting from the earthquake caused about 131 casualties. Lasting nearly four minutes, it was the most powerful recorded earthquake in U.S. and North American history and the second most powerful ever measured by seismograph. It had a magnitude of 9.2, at the time making it the second largest earthquake in recorded history, and the powerful earthquake produced liquefaction in the region. Ground fissures and failures caused major structural damage in several communities, much damage to property and several landslides. Anchorage sustained great destruction or damage to many inadequately engineered houses, buildings, and infrastructure (paved streets, sidewalks, water and sewer mains, electrical systems, and other man-made equipment), particularly in the several landslide zones. Two hundred miles southwest, some areas near were permanently raised by 30 feet (9.1 m). Southeast of Anchorage, areas around the head of Turnagain Arm near Girdwood and Portage dropped as much as 8 feet (2.4 m), requiring reconstruction and fill to raise the Seward Highway above the new high tide mark. In Prince William Sound, Port Valdez suffered a massive underwater landslide, resulting in the deaths of 30 people between the collapse of the Valdez city harbor and docks, and inside the ship that was docked there at the time. Nearby, a 27-foot (8.2 m) tsunami destroyed the village of Chenega, killing 23 of the 68 people who lived there. Post-quake tsunamis severely affected other Alaskan communities, as well as people and property as far as  British Columbia, Oregon, and California. Tsunamis also caused damage in Hawaii and Japan. Evidence of motion directly related to the earthquake was reported from all over the planet.

AEIC.(2002) The Great Alaska Earthquake of 1964. Retrieved March 26 from  http://www.aeic.alaska.edu/quakes/Alaska_1964_earthquake.html

Sokolowski, Thomas.(1991) The Great Alaskan Earthquake & Tsunami of 1964. Retrieved March 26 from http://wcatwc.arh.noaa.gov/64quake.htm

USGS.gov (2003) Prince William Sound Alaska Earthquake. Retrieved March 26 from http://earthquake.usgs.gov/earthquakes/states/events/1964_03_28.php

Earthquakes IV

Perhaps one of the worst natural disasters in our nations history was the San Francisco earthquake of 1906. The quake lasted only a minute. Modern analysis estimates it registered a staggering 8.25 on the Richter scale. The greatest destruction came from the fires the quake ignited. These ravaged the city for three days before burning themselves out. The maelstrom destroyed 490 city blocks, a total of 25,000 buildings, made over 250,000 homeless and killed between 450 and 700. Damage estimates topped $350,000,000. Three eye witnesses described their experiences: "Of a sudden we had found ourselves staggering and reeling. It was as if the earth was slipping gently from under our feet. Then came the sickening swaying of the earth that threw us flat upon our faces. We struggled in the street. We could not get on our feet. Then it seemed as though my head were split with the roar that crashed into my ears. Big buildings were crumbling as one might crush a biscuit in one's hand." The fires that spread wildly throughout the city were a direct result of ruptured gas lines. fighting the fires was nearly impossible.

USGS.gov (2003) The Great 1906 San Francisco Earthquake. Retrieved March 15 2011 from http://earthquake.usgs.gov/regional/nca/1906/18april/index.php

Frantz, Chris. (2007) The Great 1906 San Francisco Earthquake. Retrieved March 15 2011 from http://www.infoplease.com/spot/sanfran1906earthquake.html

eyewitnesshistory.com (1997) The San Francisco Earthquake, 1906. Retrieved March 15 2011 from http://www.eyewitnesstohistory.com/sfeq.htm