A simple technique is developed for determining the rupture duration and stress drop of earthquakes between magnitudes 3.5 and 4.0 using the time between the P-wave onset and the first zero crossing (71/=) on seismograms from local seismic networks. This method is applied to 10 main shocks in southern California to investigate regional variations in stress drop. The initial pulse widths of 65 f...

range and the location of artificial reflectors or intermediate values at these points. A similar fictitious sources inherent in discrete wave economy can be obtained using the itrerative reflection and transmission coefficient relations number techniques. The number and spacing of wave numbers in wave number integration schemes are of Kennett. Kamel and Felsen (1981) presented a hybrid determi...

Seismic refraction profiles recorded layer. Crustal subsidence and periodic basaltic along the eastern Snake River Plain (ESRP) in southeastern Idaho during the 1978 YellowstoneSnake River Plain cooperative seismic profiling experiment are interpreted to infer the crustal velocity and attenuation (Q-i) structure of the ESRP. Travel-time and synthetic seismogram modeling of a 250 km reversed ref...

Figure 2.16: Models, seismograms and maximum amplitude distributions for two models with a fault widening towards the surface and a low velocity layer on top.. Figure 2.17: Selected seismograms, amplitude spectra and envelopes for the two models with a fault widening towards the surface and a low velocity layer on top .. Figure 4.10: Seismogram comparison of synthetics calculated with the refle...

This paper describes a series of innovations in the problem of deconvolving forward scattered P-to-S conversions. We introduce a theoretical foundation for a recently developed multichannel stacking technique and show that this process is equivalent to a spatial convolution of the incident wavefield with the discretely sampled set of station locations. We then show that deconvolution of the sta...

The single-scattering (or Born) approximation is the most fundamental assumption shared by all seismic imaging methods, and plays a crucial role in the nonlinear waveform inversion, an iterative process of linearized inversions. The Born simulator (linearized forward map) shares a computational core with the corresponding simulator (forward map), which has been well implemented in the modeling ...

The high-frequency content observed in teleseisms recorded by seismometers can be produced either by the nonlinear behavior of seismometers and digitizers (Delorey et al. 2008; Hellweg et al. 2008) or by the real Earth response. The latter include scattering from small-scale heterogeneities during seismic wave propagation (e.g., Chen and Long 2000) and high-frequency radiations from the earthqu...

Observations of seismic waves from earthquakes at depths between 100 and 200 km beneath Japan show that the initial portion of the S-wave arrival has greater duration than can be accounted for by earthquake source-time duration. The observed long duration of S waves has been explained as being caused by multiple forward scattering around the ray path between source and receiver. Array observati...

Phases that arrive near the direct SV phase, including Sp (converted at the base of the Moho), SsPmP, and shear-coupled PL (SPL) waves, collectively sample the Earth’s crust and upper mantle at oblique angles and therefore have the potential to produce an accurate lateral average of structural properties than teleseismic P waves. SPL waves essentially mimic the propagation characteristics of re...