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Rapid determination of earthquake magnitude using GPS for tsunami warning systems
Author(s) -
Blewitt Geoffrey,
Kreemer Corné,
Hammond William C.,
Plag HansPeter,
Stein Seth,
Okal Emile
Publication year - 2006
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2006gl026145
Subject(s) - seismology , global positioning system , geology , magnitude (astronomy) , tsunami earthquake , warning system , tsunami wave , earthquake magnitude , geodesy , earthquake casualty estimation , earthquake prediction , earthquake simulation , earthquake warning system , displacement (psychology) , moment magnitude scale , earthquake scenario , seismic hazard , computer science , telecommunications , physics , geometry , mathematics , astronomy , scaling , psychology , psychotherapist
The 26 December 2004 Sumatra earthquake (M w 9.2–9.3) generated the most deadly tsunami in history. Yet within the first hour, the true danger of a major oceanwide tsunami was not indicated by seismic magnitude estimates, which were far too low (M w 8.0–8.5). This problem relates to the inherent saturation of early seismic‐wave methods. Here we show that the earthquake's true size and tsunami potential can be determined using Global Positioning System (GPS) data up to only 15 min after earthquake initiation, by tracking the mean displacement of the Earth's surface associated with the arrival of seismic waves. Within minutes, displacements of >10 mm are detectable as far away as India, consistent with results using weeks of data after the event. These displacements imply M w 9.0 ± 0.1, indicating a high tsunami potential. This suggests existing GPS infrastructure could be developed into an effective component of tsunami warning systems.