In order to keep people as safe as possible during an earthquake special building codes have been developed for houses, roads, buildings and bridges. The United States Geological Society (USGS) uses the best seismic science available to keep up-to-date maps that show levels of danger from the lowest hazard to highest standard. These maps help cities know what level of building codes they need.
There are four areas of the United States that demonstrate the highest level danger: along the coast of the Pacific Ocean including Hawaii, southern Alaska, on the coast near the Atlantic Ocean in South Carolina and the five state border where the Ohio River branches off the Mississippi River. The highest hazard measures 64% g or more. Different hazard levels show the levels of “horizontal shaking that have a 2-in-100 chance of being exceed in a 50-year period” where “shaking is defined as the percentage of g when g equals the acceleration of an object due to gravity” (USGS Hazard Map, 2008).
Home North Carolina has had no danger in the last seven days from an earthquake. The danger levels for North Carolina are highest in the southern most corner of North Carolina which borders South Carolina and the Atlantic Ocean. At that point the hazard rating is yellow (16-32%g). Most of the state is colored green which indicates a low hazard of 8-16%g. The northeast portion of North Carolina is the safest of all. It is blue with 4-9%g. (USGS, 2011)
Last 7 days of earthquake data. On October 23 a Magnitude 7.2 struck East Turkey at 10:41:21. The depth of the earthquake was 12.4 miles. (USGS, 2011)
An S-shaped line of earthquakes runs along the eastern coast of Asia through the islands of Japan and continues south through Indonesia and the new Guinea. The bottom half of the S is shaped by the islands curving north of the Australian coast through Kermadec Islands and ending at New Zealand. (USGS, 2011)
On the North American continent earthquakes occur on the curve of the Alaska piece land that reaches into the Atlantic Ocean. The Kodiak Island Region, Kenai Peninsula, the Alaska Peninsula and up into Central Alaska are all along an earthquake fault line. Heading south the earthquakes start again along the fault line that runs through California down the coast into Mexico and Central America. A shorter fault line lies to the east of Central America under Jamaica and the neighboring islands. The South American continent is very prone to earthquakes from the southern border of Peru down through Chile. (USGS, 2011)
On the western side of Asia, Turkey has a fault line which is active. The whole Arabian Peninsula is surrounded by fault lines which effect the countries of Iran and Iraq (both which border Turkey), Oman, Yemen and Saudi Arabia. (USGS, 2011)
The fault line from Turkey continues into the northern part of the Mediterranean Sea under the Greek Islands, Greece mainland and Italy.
The map of Turkey shows a lot of recent earthquakes are taking in place in one area. There are yellow and red squares on top of each other. On Sunday, October 23 a 7.2 magnitude earthquake started at 1:42 p.m. (Ankara time) which caused damage and several deaths 9 miles north northeast from Van, Turkey and 677 miles east of Ankara, Turkey. The exact epicenter was at 38.628° North, 43.486° East. (USGS, 2011)
Red areas on the map are in central California and near Oklahoma City. I wouldn’t want to live in either place unless my house was built to withstand earthquakes.
Before we bought a house or rented a place to live I would want to check to make sure that it met the building codes for earthquakes. I would make sure we had a heavy oak table or some other heavy piece of furniture that we could climb under. The FAQs give a list of emergency supplies to have on hand which is a good list of things to keep in one place in case we need those (USGS, 2011). I like the idea of planning ahead, too, by practicing and by planning where to meet in case there is an earthquake while everyone is at work and school.
I would teach everyone to stay indoors under the table unless there was a big field they could go to where they would not have to worry about buildings falling on top of them. Probably I would go through the website FAQs again with my family because I’m afraid of earthquakes. I wouldn’t want to live in a place with earthquakes.
The most destructive earthquake in the world happened on January 23, 1556 in Shensi, China. The earthquake was very strong; a magnitude of 8. The deaths reported were 830,000. The second most destructive earthquake happened recently in 2010 in Haiti. It happened on January 12, 2010 and the reported number of deaths is 316,000. It was a 7 magnitude earthquake. The island of Haiti and the people there are still suffering from the effects of the earthquake. (USGS, 2011)
The list shows that with the ability of modern science to predict earthquakes better less people have been died. For example on May 12, 2008 another earthquake, this one 7.9 Magnitude hit China and there were fewer deaths. In 2008 the reported number of deaths is 87,500 while in the most destructive earthquake mentioned above the number listed is closer to 1 million people. Comparing the same areas that historically experience earthquakes, the same type of positive result is evident. Fewer people die in modern earthquakes of the same or higher magnitude in the same place. (USGS, 2011)
Scientists measure both intensity and magnitude of earthquakes. Seismographs have been used for centuries and have gotten more sophisticated as instrumentation has been developed with computers.
Geologists help to map fault lines. When geologists recognized fault lines on the surface of the earth like surface ruptures and fault scarps they started wondering what was going on underground. As more information was learned and earthquakes were related to fault lines it became possible to target measurements along the fault lines (Earthquake FAQS).
In the USA the measurements started in about 1930 so from that time with each earthquake event scientists have understood the importance of saving lives by using their knowledge. (USGS, 2011)
Friction makes earthquake energy when tectonic plates scrape each other or when two sides of a fault line are slipping. Kinetic energy created by earthquakes can “ create new cracks in rock, energy dissipated as heat through friction, and energy elastically radiated through the earth” (FAQS, 2011). Joules are used in equations calculating earthquake energy. Biological energy is measured most often in kilocalories or calories, measures of the amount of heat energy. (USGS, 2011)
2008 United States National Seismic Hazard Maps. United States Geological System (USGS). Extmedia.kaplan.edu. April 2008. Web. 26 Oct. 2011.
All FAQs. Earthquake Myths. United States Geological Survey (USGS). Earthquake.usgs.gov. 27 Oct. 2009. Web. 28 Oct. 2011.
Dolak, K. and Tanglao, L. (2011). Turkey Earthquake Hundreds Dead Rescue Workers Dig. Abc.news. 24 Oct. 2011 Web. 26 Oct. 2011.
Earthquake Facts. United States Geological Survey (USGS). Earthquake Hazards Program. Earthquake.usgs.gove. 18 March 2011. Web. 26 Oct. 2011.
Earthquakes with 50,000 or More Deaths. Earthquake Hazards Program. United States Geological Society (USGS). 14 April 2011. Web. 28 Oct. 2011.
Latest Earthquakes in the World – Past 7 days. United States Geological Society (USGS). Earthquake.usgs.gov. 28 Oct. 2011. Web. 28 Oct. 2011.
Wald, L. The Science of Earthquakes. United States Geological Survey (USGS). Earthquake.usgs.gov. 27 Oct. 2009 Web. 27 Oct. 2011. Originally written for “The Green Frog News.”