{"64749":{"#nid":"64749","#data":{"type":"news","title":"New System Can Warn of Tsunamis Within Minutes","body":[{"value":"\u003Cp\u003ESeismologists have developed\na new system that could be used to warn future populations of an impending\ntsunami only minutes after the initial earthquake. The system, known as RTerg,\ncould help reduce the death toll by giving local residents valuable time to\nmove to safer ground. The study by researchers at the Georgia Institute of\nTechnology appears in the March 5\u003Csup\u003E \u003C\/sup\u003Eedition of Geophysical Research\nLetters. \u003C\/p\u003E\n\n\u003Cp\u003E\u201cWe developed a system that,\nin real time, successfully identified the magnitude 7.8 2010 Sumatran\nearthquake as a rare and destructive \u003Cem\u003Etsunami earthquake\u003C\/em\u003E. Using this\nsystem, we could in the future warn local populations, thus minimizing the\ndeath toll from tsunamis,\u201d said Andrew Newman, assistant professor in the\nSchool of Earth and Atmospheric Sciences. \u003C\/p\u003E\n\n\u003Cp\u003ETypically, a large\nsubduction zone earthquake ruptures at a rate near 3 kilometers\/second and\nanywhere from 20 kilometers to 50 kilometers below the earth\u2019s surface. Because\nof the depth, vertical deformation of the crust is horizontally smoothed,\ncausing the size of uplift to remain rather small. When these earthquakes occur\nin the ocean, the resulting waves may only measure about 20 centimeters high\nfor a magnitude 7.8 event. \u003C\/p\u003E\n\n\u003Cp\u003ETsunami earthquakes, however,\nare a rare class of earthquakes that rupture more slowly, at 1-1.5 kilometers\n\/second and propagate up to the sea floor, near the trench. This makes the\nvertical uplift much larger, resulting in nearby wave heights up to 10- 20\nmeters in nearby coastal environments. Such is the case of the Sumatran\nearthquake with reported wave heights of up to 17 meters, causing a death toll\nof approximately 430 people.\u003C\/p\u003E\n\n\u003Cp\u003E\u201cBecause tsunami earthquakes\nrupture in a shallow environment, we can\u0027t simply use a measurement of\nmagnitude to determine which ones will create large waves,\u201d said Newman. \u201cWhen\nthey occur, people often don\u0027t feel that they\u0027re significant, if they even feel\nthem in the first place, because they seem like they\u0027re an order of magnitude\nsmaller than they actually are.\u201d\u003C\/p\u003E\n\n\u003Cp\u003ETsunami earthquakes\ntypically rupture more slowly, last longer and are less efficient at radiating\nenergy, so when RTerg uses its algorithmic tools to find a quake matching these\nattributes, it sends an alert to the National Oceanic and Atmospheric\nAdministration\u0027s Pacific Tsunami Warning Center as well as the United States\nGeological Survey\u0027s National Earthquake Information Center. \u003C\/p\u003E\n\n\u003Cp\u003EHere\u0027s how it works. Usually\nwithin four minutes, RTerg gets a notification from one of the tsunami warning\ncenters that an earthquake has occurred. This notice gives the system the\nquake\u0027s location, depth and approximate magnitude. If the earthquake is\ndetermined to be of magnitude 6.5 or higher, it takes about a minute to request\nand receive data from around 150 seismic stations around the world. Once it\ncollects this data, it uses its algorithm to run through every second of the\nrupture and determine the incremental growth of energy and ascertain whether\nthe quake was a tsunami earthquake. \u003C\/p\u003E\n\n\u003Cp\u003ENewman and his team have\nused seismology readings from previous tsunami earthquakes, such as the one in\nNicaragua in 1992 and the one that hit Java in 2006, but the Sumatran event was\nthe first tsunami quake that occurred when RTerg was online in real time. With\nthat quake, the system identified the event as a potential tsunami earthquake\nafter eight and a half minutes, and sent a notification out shortly thereafter.\nWhen applied to a production warning system, the tool will be most valuable,\nsince analysts are available 24\/7 to evaluate the algorithm results. \u003C\/p\u003E\n\n\u003Cp\u003E\u201cFor most tsunami\nearthquakes, inundation of the coastal environment doesn\u0027t occur until about\n30-40 minutes after the quake. So we\u0027ll have about 20-30 minutes to get our\ninformation to an automatic warning system, or to the authorities,\u201d said\nNewman. \u201cThis gives us a tangible amount of time to get people out of the way.\u201d\u003C\/p\u003E\n\n\u003Cp\u003ECurrently, Newman and his\nteam are working to test and implement a technique for RTerg that could shave\nanother minute or more from the warning time. In addition, they are planning to\nrewrite the algorithm so that it can be used at all U.S. and international\nwarning centers. \u003C\/p\u003E\n\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003E\n\n\nSeismologists have developed a new system that\ncould be used to warn future populations of an impending tsunami only minutes\nafter the initial earthquake. \u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Seismologists have developed a new system that could be used to warn future populations of an impending tsunami only minutes after the initial earthquake."}],"uid":"27310","created_gmt":"2011-03-04 09:27:50","changed_gmt":"2016-10-08 03:08:18","author":"David Terraso","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2011-03-04T00:00:00-05:00","iso_date":"2011-03-04T00:00:00-05:00","tz":"America\/New_York"},"extras":[],"groups":[{"id":"1183","name":"Home"}],"categories":[{"id":"154","name":"Environment"}],"keywords":[{"id":"12237","name":"Andrew Newman"},{"id":"4896","name":"College of Sciences"},{"id":"12120","name":"earthquakes"},{"id":"166926","name":"School of Earth and Atmospheric Sciences"},{"id":"171072","name":"sumatra"},{"id":"347","name":"tsunami"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003E\u003Cstrong\u003EGeorgia Tech Media Relations\u003C\/strong\u003E\u003Cbr \/\u003ELaura Diamond\u003Cbr \/\u003E\u003Ca href=\u0022mailto:laura.diamond@comm.gatech.edu\u0022\u003Elaura.diamond@comm.gatech.edu\u003C\/a\u003E\u003Cbr \/\u003E404-894-6016\u003Cbr \/\u003EJason Maderer\u003Cbr \/\u003E\u003Ca href=\u0022mailto:maderer@gatech.edu\u0022\u003Emaderer@gatech.edu\u003C\/a\u003E\u003Cbr \/\u003E404-660-2926\u003C\/p\u003E","format":"limited_html"}],"email":["david.terraso@comm.gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}