The size and duration of the Sumatra-Andaman earthquake from far-field static offsets.
نویسندگان
چکیده
The 26 December 2004 Sumatra earthquake produced static offsets at continuously operating GPS stations at distances of up to 4500 kilometers from the epicenter. We used these displacements to model the earthquake and include consideration of the Earth's shape and depth-varying rigidity. The results imply that the average slip was >5 meters along the full length of the rupture, including the approximately 650-kilometer-long Andaman segment. Comparison of the source derived from the far-field static offsets with seismically derived estimates suggests that 25 to 35% of the total moment release occurred at periods greater than 1 hour. Taking into consideration the strong dip dependence of moment estimates, the magnitude of the earthquake did not exceed Mw = 9.2.
منابع مشابه
Global deformation from the great 2004 Sumatra-Andaman Earthquake observed by GPS: Implications for rupture process and global reference frame
Static coseismic offsets >1 mm are observed up to 7800 km away from the great Sumatra-Andaman earthquake of 26 Dec. 2004 using global GPS network data. We investigate the rupture process based on far-field continuous GPS data. To reduce error in the coseismic offset estimates due to post-seismic deformation in the days following the main shock, we simultaneously fit a model of coand postseismic...
متن کاملSeismological Aspects of the December 2004 Great Sumatra-Andaman Earthquake
The 2004 Great Sumatra-Andaman earthquake had an average source duration of about 500 sec. and a rupture length of 1 ,200–1,300 km. The seismic moment, M0, determined with a finite source model, was 6.5 1022 N-m, which corresponds to Mw=9.18. Allowing for the uncertainties in the current M0 determinations, Mw is in the range of 9.1 to 9.3. The tsunami magnitude Mt is 9.1, suggesting that the ov...
متن کاملStudies on Tiny and Huge Seismic Sources Using Long Period Surface Waves: from the Hum to 2004 Sumatra-andaman Earthquake
Studies on tiny and huge seismic sources using long period surface waves: From the hum to 2004 Sumatra-Andaman earthquake. Abstract Studies on tiny and huge seismic sources using long period surface waves: From the hum to 2004 Sumatra-Andaman earthquake. We study the source processes of two extreme cases, the hum of the Earth and the 2004 great Sumatra-Andaman earthquake, by using long period s...
متن کاملRupture Properties of the Giant Sumatra Earthquake Imaged by Empirical Green’s Function Analysis
Empirical green’s function (EGF) analysis has remained little used to image the rupture properties of the giant 26 December 2004 Sumatra earthquake. The 2 November 2002 foreshock (Mw 7.2), close to the mainshock epicenter, gives us the opportunity to use its waveforms to empirically simulate the Rayleigh-wave propagation of the Sumatra earthquake. We first show that the exceptional size of the ...
متن کاملCrustal dilatation observed by GRACE after the 2004 Sumatra-Andaman earthquake.
We report the detection of an earthquake by a space-based measurement. The Gravity Recovery and Climate Experiment (GRACE) satellites observed a +/-15-microgalileo gravity change induced by the great December 2004 Sumatra-Andaman earthquake. Coseismic deformation produces sudden changes in the gravity field by vertical displacement of Earth's layered density structure and by changing the densit...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Science
دوره 308 5729 شماره
صفحات -
تاریخ انتشار 2005