Rupture Process of the 2004 Sumatra-Andaman Earthquake

Abstract

We computed the global wavefield excited by Model III using the spectral element method (SEM) (1) for a 3D Earth model composed of mantle model s20rts (1), model Crust 2.0 (2), and topography from ETOPO5. We show the predicted velocities and displacements on the Earth's surface as movies. The 3D simulations were used to calibrate the effect of 3D structure on the 1D waveforms used in the inversion for Model III. By comparing the fits of synthetics computed for different models to data that were not used in the inversions these synthetics can be used to distinguish between models.This was done qualitatively when developing model III to estimate the improvements between successive versions of the model. The waveforms for model III match the overall amplitude and directivity in observed seismograms (Fig. S1) over a wide

Detailed rupture imaging of the 25 April 2015 Nepal earthquake using teleseismic P waves

“…The red line shows the expected rupture duration for a fault length of 160 km and an average rupture velocity of 2.9 km/s. (bottom right) P wave displacements versus directivity parameter [Ammon et al, 2005], assuming…”

“…This rupture length agrees well with the aftershock distribution. To resolve details during the rupture propagation, we plot the seismograms versus the directivity parameter defined in Ammon et al [2005] and Zhan et al [2014] (see supporting information), assuming a rupture direction of 130 ∘ . As shown in Figure 1, this plot reveals three distinct subevents, with times and epicentral distances that can be directly estimated from the intercepts and slopes of lines connecting the subevent pulses on each seismogram.…”

Global evaluation of large earthquake energy from 1997 through mid-2010

“…[13] Because some large earthquakes have rupture durations that far exceed the 70 s window of evaluation in the Newman and Okal [1998] study, most notably the approximately 540 s rupture of the 2004 Sumatran earthquake [Ammon et al, 2005;Weinstein and Okal, 2005;Ni et al, 2005], it was necessary to adapt the method to all events for variable source durations. This is achieved by making averaged incremental measurements of energy starting with the initial P arrival while also increasing the window of the waveforms analyzed by 1 s increments.…”

Source characteristics of moderate-to-strong earthquakes in the Nantou area, Taiwan: insight from strong ground motion simulations

“…The empirical Green's function method is a well-known and conventional technique for studying the source properties of earthquakes by canceling out the effects of site amplification and propagation path (e.g., Velasco et al 1994;Irikura and Kamae 1994;Lay and Wallace 1995;Ammon et al 2005). Here, we applied EGFM to determine SMGA, which can be considered the characteristic area with a uniform, high slip velocity within the total rupture plane (Miyake et al 2003).…”