Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (7) Citing Articles via Google Scholar Google Scholar Articles by Shi, J. Articles by Kim, W.-Y. Search for Related Content GeoRef GeoRef Citation

Determination of Seismic Energy from Lg Waves

Lamont-Doherty Earth Observatory of Columbia University
Palisades, New York 10964
richards{at}ldeo.columbia.edu
(J. S., P. G. R., W.-Y. K.)
Department of Earth and Environmental Sciences of Columbia University
Palisades, New York 10964
(J. S., P. G. R.)

Manuscript received 4 February 1998.

Seismic energy is a physical concept related to broadband information on the source radiation; this is different from seismic moment, which is related to low-frequency information. Improved estimates of seismic moment and radiated energy can improve the scientific framework for interpreting observed seismicity in terms of physical source processes. This study evaluates the utility of regional Lg waves, the dominant feature of seismograms for regional earthquakes, for the estimation of radiated seismic energy.

The rms Lg, which is defined as the root mean square of Lg-wave ground velocity within a certain group velocity range, is proportional to the square root of Lg-wave-radiated energy flux. We find that rms Lg is a good quantity for estimating the energy release of earthquakes because a large fraction of the total seismic energy is radiated as Lg waves.

We scale the network-averaged rms Lg value to a reference distance of 100 km for a set of 52 earthquakes in the northeastern United States, using an empirically-derived relation between rms Lg and epicentral distance. We apply the source parameters, estimated for these earthquakes, to Boatwright's deceleration source model and calculate the total seismic energy expected to have been radiated by each event, assuming it can be modeled by this source. We then obtain for earthquakes in the northeastern United States the scaling of the total radiated seismic energy of earthquakes with network-averaged rms Lg values.

From synthetic seismograms, it is found that different velocity structures have an effect on the efficiency of Lg-wave radiation. Using measurements of rms Lg made from synthetics, we find that the vertical strike-slip source tends to radiate less Lg-wave energy than other source mechanisms.

This article has been cited by other articles:

				S. Dineva and R. Mereu Energy Magnitude: A Case Study for Southern Ontario/Western Quebec (Canada) Seismological Research Letters, January 1, 2009; 80(1): 136 - 148. [Abstract] [Full Text] [PDF]

				Lg-Wave Cross Correlation and Double-Difference Location: Application to the 1999 Xiuyan, China, Sequence Bulletin of the Seismological Society of America, June 1, 2004; 94(3): 867 - 879.

				Reconciling Teleseismic and Regional Estimates of Seismic Energy Bulletin of the Seismological Society of America, October 1, 2003; 93(5): 2123 - 2130.

				A Numerical Investigation of Lg Geometrical Spreading Bulletin of the Seismological Society of America, December 1, 2002; 92(8): 3067 - 3079.