Please use this identifier to cite or link to this item: http://hdl.handle.net/2122/3134
AuthorsLomax, A.* 
Michelini, A.* 
Piatanesi, A.* 
TitleAn energy-duration procedure for rapid determination of earthquake magnitude and tsunamigenic potential
Issue Date20-Apr-2007
Series/Report no./170(2007)
DOI10.1111/j.1365-246X.2007.03469.x
URIhttp://hdl.handle.net/2122/3134
Keywordsearthquake
magnitude
seismic moment
seismograms
tsunami
waveform analysis
Subject Classification04. Solid Earth::04.06. Seismology::04.06.03. Earthquake source and dynamics 
AbstractWe introduce a rapid and robust, energy-duration procedure, based on the Haskell, extendedsource model, to obtain an earthquake moment and a moment magnitude, MED. Using seismograms at teleseismic distances (30!–90!), this procedure combines radiated seismic energy measures on the P to S interval of broadband signals and source duration measures on highfrequency, P-wave signals. The MED energy-duration magnitude is scaled to correspond to the Global Centroid-Moment Tensor (CMT) moment-magnitude, MCMT w , and can be calculated within about 20 min or less after origin time (OT). The measured energy and duration values also provide the energy-to-moment ratio, !, used for identification of tsunami earthquakes. The MED magnitudes for a set of recent, large earthquakes match closely MCMT w , even for the largest, great earthquakes; these results imply that the MED measure is accurate and does not saturate. After the 2004 December 26 Sumatra-Andaman mega-thrust earthquake, magnitude estimates available within 1 hr of OT ranged from M = 8.0 to 8.5, the CMT magnitude, available about 3 hr after OT, was MCMT w = 9.0, and, several months after the event, Mw = 9.1–9.3 was obtained from analysis of the earth normal modes. The energy-duration magnitude for this event is MED = 9.2, a measure that is potentially available within 20 min after OT. After the 2006 July 17, Java earthquake, the magnitude was evaluated at M = 7.2 at 17 min after OT, the CMT magnitude, available about 1 hr after OT, was MCMT w = 7.7; the energy-duration results for this event give MED = 7.8, with a very long source duration of about 160 s, and a very low ! value, indicating a possible tsunami earthquake.
Appears in Collections:Papers Published / Papers in press

Files in This Item:
File Description SizeFormat 
2007_GJI_Magnitude_ed.pdfmain article531.38 kBAdobe PDFView/Open    Request a copy
EnergyDurationMagnitude_v2.0.pdfunformatted final version1.31 MBAdobe PDFView/Open
Show full item record

Page view(s)

87
checked on Apr 30, 2017

Download(s)

379
checked on Apr 30, 2017

Google ScholarTM

Check

Altmetric