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

Earthquakes III

On March 11th at approximately 12:45 a massive earthquake rocked the coast of Japan. the magnitude of this earthquake was 9.0 and occurred near the northeast coast of Honshu, Japan, resulted from thrust faulting on or near the subduction zone plate boundary between the Pacific and North America plates. The March 11th earthquake was preceded by a series of large foreshocks over the previous two days, beginning on March 9th with a M 7.2 event approximately 40 km from the epicenter of the March 11 earthquake, and continuing with another three earthquakes greater than M 6 on the same day. (U.S. Geologic Survey, 2011)
  
The March 11th earthquake was greater than any other post-1900 plate-boundary thrust-fault earthquakes in  Japan. No other earthquake had surpassed a magnitude of 8. However, the earthquake was not the end of the destruction. as a direct result of the quake a 30 foot tsunami. the tsunami alone killed hundreds of people as it swept away boats, cars and homes while widespread fires burned out of control. (The Huffington Post, 2011)
 Experts are saying that it may take up to five years for japan to recover from all of the damage caused by the earthquake. According to the world bank an estimated 235 billion dollars of damage has been done. Japan is also dealing with a crisis at a large nuclear power plant. authorities are trying to regain control of the plant after a fire had broken out after the earthquake. if a meltdown were to occur the amount of damage would be incredible. likely thousands more would be killed from radiation poisoning; after death tolls have already reached approximately 10,000. (Alertnet, 2011)



 AlertNet.org (2011) The Humanitarian News Site Japan Quake and Tsunami. Retrieved March 20 2011 from http://www.trust.org/alertnet/news/special-coverage-japan-quake-and-pacific-tsunami/

TheHuffingtonPost.com (2011) Japan Earthquake 2011: 8.9 Magnitude Earthquake Hits, 30-Foot Tsunami Triggered. Retrieved March 20 2011 from http://www.huffingtonpost.com/2011/03/11/japan-earthquake-tsunami_n_834380.html

USGS.gov (2011) Magnitude 9.0 - Near The Cost of Honshu, Japan. Retrieved March 20 2011 from http://earthquake.usgs.gov/earthquakes/eqinthenews/2011/usc0001xgp/#summary

Earthquakes II

Throughout the history of the earth, earthquakes have been recorded for their unbelievable
destructive forces.  Earthquakes can and do often strike without warning. They have the capability to level large cities and kill thousands of innocent people.   Not only can earthquakes bring harm to our communities through these methods of destruction, but they can also cause millions of dollars worth of property damage to the areas they destroy.  These natural disasters have killed thousands in the U.S. alone since 1900.(National Geographic)The most famous earthquake in U.S. history is that of 1906 in San Francisco California. An estimated 3000 people lost their lives on April 18^th 1906. It is difficult to believe that so much damage was done as a result of 45-60 seconds of shaking. The damage done was not only a result of the earthquake. The seismic disturbance also caused an enormous fire to break out throughout the city. (U.S. Geological Survey) It is important to understand good safety precautions if you find yourself in an earthquake situation. If you are indoors drop to the ground and seek immediate cover; Preferably under a table or piece of furniture. If this is not possible cover your head and crouch in the corner of the room or building. As with nearly all natural disasters It is important to say away from glass and windows. Aside from popular belief it is only a good idea to stay in a doorway if you know it is strongly supported and remain indoors until the shaking stops. (FEMA Department of Homeland Security) 

Corey Dwyer

National Geographic (2011, February.) Earthquakes. retrieved February 20 from  http://environment.nationalgeographic.com/environment/natural-disasters/earthquake-profile.html

Department of Homeland Security (2011, February.) What to Do During an Earthquake. retrieved February 20 from http://www.fema.gov/hazard/earthquake/eq_during.shtm

EHP Web Team (2009, January.) The Great 1906 San Francisco Quake. retrieved February 20 from http://earthquake.usgs.gov/regional/nca/1906/18april/index.php

Earthquakes

Perhaps one of the most frightening and destructive natural disasters an individual can find themselves in is an earthquake. Earthquakes are centered on the scientific theory of plate tectonics. The idea of plate tectonics begins with the earth's lithosphere including the crust which is made up of constantly moving plates. These large plates move at an extremely slow rate of speed building up pressure when they move over, or grind against one another. Once enough pressure is built up over time the energy is released in the form of an earthquake. (Sebeck, 2004)

 When these natural disasters occur in populated areas the result can be large loss of human life and great property destruction. The study of these phenomena is relatively new as far as the science world is concerned. Today buildings are being structurally designed in ways that will prevent them from falling over in the event of an earthquake. When an earthquake occurs the energy released is in the form of seismic waves. These waves are used to determine the strength of the earthquake. (U.S. Search and Rescue Task Force, 2000) Earthquakes most often occur along faults. A fault can be defined as "a three-dimensional surface within the planet Earth. At the fault, rocks have broken. The rocks on one side of the fault have moved past the rocks on the other side. In contrast, a fault line is a line that stretches along the ground. The fault line is where the fault cuts the Earth's surface." (U.S. Geologic Survey, 2003) perhaps the most famous earthquake in U.S. history occurred in 1906 along the San Andreas Fault. The result of the earthquake left California in ruins killing over 700 people.

As mentioned before the science of plate tectonics and earthquakes is relatively new. In order to keep people safe it is important that we continue to make advancements in earthquake predicting technology. Ideally we would like to be able to predict an earthquake early enough to allow proper disaster response thus minimizing potential loss of life and property.  However the prediction of an earthquake is a very difficult thing to do. Today scientists study past earthquakes to try to determine when future earthquakes may occur. However, this method is not the most practical. For example, between 1836 and 1911 four 6.8 or higher magnitude earthquakes occurred in the San Francisco are along with many earthquakes between 6 and 6.5. Since 1911 to date no earthquakes above a magnitude of six have occurred in the San Francisco area. (U.S. Search and Rescue Task Force, 2000)

Corey Dwyer

Sebeck, Julie. (2005, April.) Plate Tectonics. Retrieved February 6 2011 from http://www.cotf.edu/ete/modules/msese/earthsysflr/plates1.html

Lebov, Steven. (2000) Earthquakes. Retrieved February 6 2011 from http://www.ussartf.org/earthquakes.htm

USGS.gov (2003) Where are the Fault Lines in the United States? Retrieved February 6 2011 from http://earthquake.usgs.gov/learn/topics/faults_east.php