Publications
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Soil-geomorphic significance of land surface characteristics in an arid mountain range, Mojave Desert, USA
Mountains comprise an extensive and visually prominent portion of the landscape in the Mojave Desert, California. Landform surface properties influence the role these mountains have in geomorphic processes such as dust flux and surface hydrology across the region. The primary goal of this study was to describe and quantify land surface properties of arid-mountain landforms as a step toward unravel
Authors
D.R. Hirmas, R.C. Graham, K.J. Kendrick
Coulomb stress change sensitivity due to variability in mainshock source models and receiving fault parameters: A case study of the 2010-2011 Christchurch, New Zealand, earthquakes
Strong aftershocks following major earthquakes present significant challenges for infrastructure recovery as well as for emergency rescue efforts. A tragic instance of this is the 22 February 2011 Mw 6.3 Christchurch aftershock in New Zealand, which caused more than 100 deaths while the 2010 Mw 7.1 Canterbury mainshock did not cause a single fatality (Figure 1). Therefore, substantial efforts have
Authors
Zhongwen Zhan, Bikai Jin, Shengji Wei, Robert W. Graves
Deep rock damage in the san andreas fault revealed by P- and S-type fault-zone-guided waves
Damage to fault-zone rocks during fault slip results in the formation of a channel of low seismic-wave velocities. Within such channels guided seismic waves, denoted by Fg, can propagate. Here we show with core samples, well logs and Fg-waves that such a channel is crossed by the SAFOD (San Andreas Fault Observatory at Depth) borehole at a depth of 2.7 km near Parkfield, California, USA. This late
Authors
William L. Ellsworth, Peter E. Malin
Inversion of ground-motion data from a seismometer array for rotation using a modification of Jaeger's method
We develop a new way to invert 2D translational waveforms using Jaeger's (1969) formula to derive rotational ground motions about one axis and estimate the errors in them using techniques from statistical multivariate analysis. This procedure can be used to derive rotational ground motions and strains using arrayed translational data, thus providing an efficient way to calibrate the performance of
Authors
Wu-Cheng Chi, W.H.K. Lee, J.A.D. Aston, C.J. Lin, C.-C. Liu
Measurements of Martian dust devil winds with HiRISE
We report wind measurements within Martian dust devils observed in plan view from the High Resolution Imaging Science Experiment (HiRISE) orbiting Mars. The central color swath of the HiRISE instrument has three separate charge‐coupled devices (CCDs) and color filters that observe the surface in rapid cadence. Active features, such as dust devils, appear in motion when observed by this region of t
Authors
D.S. Choi, Colin M. Dundas
Landslide stability: Role of rainfall-induced, laterally propagating, pore-pressure waves
The Johnson Creek Landslide is a translational slide in seaward-dipping Miocene siltstone and sandstone (Astoria Formation) and an overlying Quaternary marine terrace deposit. The basal slide plane slopes sub-parallel to the dip of the Miocene rocks, except beneath the back-tilted toe block, where it slopes inland. Rainfall events raise pore-water pressure in the basal shear zone in the form of pu
Authors
G. R. Priest, W.H. Schulz, W. L. Ellis, J.A. Allan, A. R. Niem, W. A. Niem
Recovering from the ShakeOut earthquake
Recovery from an earthquake like the M7.8 ShakeOut Scenario will be a major endeavor taking many years to complete. Hundreds of Southern California municipalities will be affected; most lack recovery plans or previous disaster experience. To support recovery planning this paper 1) extends the regional ShakeOut Scenario analysis into the recovery period using a recovery model, 2) localizes analyses
Authors
Anne Wein, Laurie Johnson, Richard Bernknopf
High-frequency filtering of strong-motion records
The influence of noise in strong-motion records is most problematic at low and high frequencies where the signal to noise ratio is commonly low compared to that in the mid-spectrum. The impact of low-frequency noise (5 Hz) on computed pseudo-absolute response spectral accelerations (PSAs). In contrast to the case of low-frequency noise our analysis shows that filtering to remove high-frequency noi
Authors
J. Douglas, D. M. Boore
Economic impacts of the ShakeOut scenario
For the ShakeOut Earthquake Scenario, we estimate $68 billion in direct and indirect business interruption (BI) and $11 billion in related costs in addition to the $113 billion in property damage in an eight-county Southern California region. The modeled conduits of shock to the economy are property damage and lifeline service outages that affect the economy’s ability to produce. Property damage f
Authors
A. Rose, D. Wei, A. Wein
Spring-fall asymmetry of substorm strength, geomagnetic activity and solar wind: Implications for semiannual variation and solar hemispheric asymmetry
We study the seasonal variation of substorms, geomagnetic activity and their solar wind drivers in 1993–2008. The number of substorms and substorm mean duration depict an annual variation with maxima in Winter and Summer, respectively, reflecting the annual change of the local ionosphere. In contradiction, substorm mean amplitude, substorm total efficiency and global geomagnetic activity show a do
Authors
K. Mursula, E. Tanskanen, J.J. Love
8 March 2010 Elazığ-Kovancilar (Turkey) Earthquake: observations on ground motions and building damage
An earthquake of MW = 6.1 occurred in the Elazığ region of eastern Turkey on 8 March 2010 at 02:32:34 UTC. The United States Geological Survey (USGS) reported the epicenter of the earthquake as 38.873°N-39.981°E with a focal depth of 12 km. Forty-two people lost their lives and 137 were injured during the event. The earthquake was reported to be on the left-lateral strike-slip east Anatolian fault
Authors
Sinan Akkar, A. Aldemir, A. Askan, S. Bakir, E. Canbay, I.O. Demirel, M.A. Erberik, Z. Gulerce, Polat Gülkan, Erol Kalkan, S. Prakash, M.A. Sandikkaya, V. Sevilgen, B. Ugurhan, E. Yenier
Extreme volcanism on Io: Latest insights at the end of Galileo era
Galileo has now completed 7 years exploring Jupiter. The spacecraft obtained breathtaking views of the four major satellites, and studied Jupiter's clouds and atmospheric composition, rings, small satellites, and magnetic field. It had five successful close flybys and many distant observations of Io. Scientists already knew from Voyager and Earth‐based astronomy that Io is by far the most volcanic
Authors
Jeffrey S. Kargel, Robert R. Carlson, Ashley G. Davies, Bruce Fegley, Alan R. Gillespie, Ronald Greeley, Robert G. Howells, Kandis Lea Jessup, Lucas Kamp, Laszlo P. Keszthelyi, Rosaly Lopes, Timothy MacIntyre, Franck Marchis, Alfred McEwen, Moses P. Milazzo, Jason Perry, Jani Radebaugh, Laura Schaefer, Nicholas Schmerr, William Smythe, John M. Spencer, David A. Williams, Ju Zhang, Mikhail Zolotov