Estimation of scattering properties of lithosphere of Kamchatka based on Monte-Carlo simulation of record envelope of a near earthquake

Details Estimation of scattering properties of lithosphere of Kamchatka based on Monte-Carlo simulation of record envelope of a near earthquake Estimation of scattering properties of lithosphere of Kamchatka based on Monte-Carlo simulation of record envelope of a near earthquake

Nov 1990

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1990pepi...64...52a&link_type=abstract

Physics of the Earth and Planetary Interiors, Volume 64, Issue 1, p. 52-67.

Physics

38

Scientific paper

Several models which describe the intensity of single and multiply scattered waves radiated by an instant point source into a medium with uniformly dispersed scatterers and uniform absorption are reviewed. The model of multiple low-angle scattering (MLAS) is then considered and we show that in the realistic case of dominantly forward scattering one can employ the model to determine the mean free path l from pulse broadening of scattered waves. This fast (~ r2) pulse broadening leads to r-2 amplitude decay and can explain known fast-amplitude decay of short-range magnitude calibration curves and of peak acceleration attenuation laws.
Since analytical theory is lacking for an important case of scattered body waves at source distances around r = l, we employ the previously developed technique of Monte-Carlo simulation of a scattered wavefield to obtain a set of theoretical formulae and master curves. These enable us to estimate mean free path l in two independent ways: from intensity ratio of direct and scattered waves (lA) and from pulse duration or retardation (lT). In both cases, the estimates must depend only weakly on errors of Q determination. We applied the developed theory to the interpretation of records of earthquakes near Kamchatka recorded by frequency selecting (`ChISS') stations. For Shipunsky (SPN) station in the 1.5-6.0 Hz frequency range the estimates are lA ~ 150 km, lT ~ 110 km. In the 6-25 Hz range, lA is decreasing, roughly as ƒ;-0.65.
We could expect that improved theoretical coda shapes will resemble the observed ones, leading to accurate intrinsic Q estimates. This is not the case however, and our Q estimates depend in fact on the choice of lapse time window. This indicates that uniform medium models are insufficient for interpretation. We could demonstrate directly the depth dependence of l based on lT estimates.

Affiliated with

Also associated with

No associations

Rating

Estimation of scattering properties of lithosphere of Kamchatka based on Monte-Carlo simulation of record envelope of a near earthquake does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Estimation of scattering properties of lithosphere of Kamchatka based on Monte-Carlo simulation of record envelope of a near earthquake, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Estimation of scattering properties of lithosphere of Kamchatka based on Monte-Carlo simulation of record envelope of a near earthquake will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-842821