Heidi Houston

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The disastrous Sumatra-Andaman earthquake of 26 December 2004 was one of the largest ever recorded. The damage potential of such earthquakes depends on the extent and magnitude of fault slip. The first reliable moment magnitude estimate of 9.0 was obtained several hours after the Sumatra-Andaman earthquake, but more recent, longer-period, normal-mode(More)
S51C-0170X. Reasenberg, P.A. & Jones, L.M., 1989. Earthquake hazard after a mainshock in California, Science, 243, 1173–1176. Reasenberg, P.A. & Jones, L.M., 1994. Earthquake aftershocks: update, Science, 265, 1251–1252. Robertson, M.C., Sammis, C.G., Sahimi, M. & Martin, A.J., 1995. Fractal analysis of three-dimensional spatial distributions of earthquakes(More)
Source characteristics of the Sept. 19, 1985 Michoacan, Mexico earthquake and its aftershock on Sept. 21 were inferred from broadband and short-period teleseismic GDSN records. We Fourier-transformed the P waves, corrected for instrument response, attenuation, geometrical spreading, and radiation pattern (including the depth phases), and then averaged to(More)
[1] The discovery of non‐volcanic tremor (NVT) has opened a new window to observe major Earth plate boundaries. However, the spectral characteristics of NVT have not been well studied due to poor signal‐ to‐noise ratio (SNR) on individual seismograms. We estimate the spectral content of Cascadia tremor between 2.5 and 20 Hz by suppressing noise using array(More)
The time history of energy release during earthquakes illuminates the process of failure, which remains enigmatic for events deeper than about 100 kilometers. Stacks of teleseismic records from regional arrays for 122 intermediate (depths of 100 to 350 kilometers) and deep (depths of 350 to 700 kilometers) earthquakes show that the temporal pattern of(More)
We examine the horizontal motions at close stations from earthquakes in the Loma Prieta and Whittier Narrows sequences tostudy the shear wave polarizations. We use a dense, six station array recording 10 aftershocks for the former, and use two events and 11 stations across the Los Angeles area for the latter. We compute the average azimuth of strongest(More)
1 SUMMARY. We compare the source time functions (moment release rates) of three large California mainshocks with the seismic moment release rates during their aftershock sequences. Aftershock m o m e n t release rates, computed by summing aftershock moments in time intervals, follow Omori's law from minutes to months after the mainshockk furthermore, in(More)
We studied strong-motion spectra observed for three Mw 7.8 to 8.0 earthquakes (the 1985 Michoacan, Mexico; 1985 Valparaiso, Chile; and 1983 Akita-Oki, Japan earthquakes). We determined the decay of spectral amplitude with distance from the station, considering different measures of distance from a finite fault. We compared strong-motion spectra (Fourier(More)