Publications
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Annual and seasonal distribution of intertidal foraminifera and stable carbon isotope geochemistry, Bandon Marsh, Oregon, USA
We investigated the influence of inter-annual and seasonal differences on the distribution of live and dead foraminifera, and the inter-annual variability of stable carbon isotopes (d13C), total organic carbon (TOC) values and carbon to nitrogen (C/N) ratios in bulk sediments from intertidal environments of Bandon Marsh (Oregon, USA). Living and dead foraminiferal species from 10 stations were ana
Authors
Yvonne Milker, Benjamin Horton, Christopher Vane, Simon Engelhart, Alan R. Nelson, Robert C. Witter, Nicole S. Khan, William Bridgeland
Holocene and latest Pleistocene paleoseismology of the Salt Lake City segment of the Wasatch Fault Zone, Utah, at the Penrose Drive Trench Site
The Salt Lake City segment (SLCS) of the Wasatch fault zone (WFZ) and the West Valley fault zone (WVFZ) compromise Holocene-active normal faults that bound a large intrabasin graben in northern Salt Lake Valley and have evidence of recurrent, large-magnitude (M ~6-7) surface-faulting earthquakes. However, at the time of this investigation, questions remained regarding the timing, displacement, and
Authors
Christopher B. DuRoss, Michael D. Hylland, Greg N. McDonald, Anthony J. Crone, Stephen F. Personius, Ryan D. Gold, Shannon Mahan
Southern San Andreas Fault evaluation field activity: approaches to measuring small geomorphic offsets--challenges and recommendations for active fault studies
In southern California, where fast slip rates and sparse vegetation contribute to crisp expression of faults and microtopography, field and high‐resolution topographic data (
Authors
Katherine M. Scharer, J. Barrett Salisbury, J. Ramon Arrowsmith, Thomas K. Rockwell
Ancient aqueous environments at Endeavour crater, Mars
Opportunity has investigated in detail rocks on the rim of the Noachian age Endeavour crater, where orbital spectral reflectance signatures indicate the presence of Fe+3-rich smectites. The signatures are associated with fine-grained, layered rocks containing spherules of diagenetic or impact origin. The layered rocks are overlain by breccias, and both units are cut by calcium sulfate veins precip
Authors
R. E. Arvidson, S. W. Squyres, J.F. Bell, J.G. Catalano, B. C. Clark, L.S. Crumpler, P.A. de Souza, A.G. Fairén, W. H. Farrand, V.K. Fox, Ralf Gellert, A. Ghosh, M.P. Golombeck, J.P. Grotzinger, E.A. Guinness, Kenneth E. Herkenhoff, B.L. Jolliff, A.H. Knoll, R. Li, S. M. McLennan, D. W. Ming, D. W. Mittlefehldt, Johnnie N. Moore, R.V. Morris, S.L. Murchie, T. J. Parker, G. Paulsen, J.W. Rice, S. W. Ruff, M. D. Smith, M.J. Wolff
Diverse rupture modes for surface-deforming upper plate earthquakes in the southern Puget Lowland of Washington State
Earthquake prehistory of the southern Puget Lowland, in the north-south compressive regime of the migrating Cascadia forearc, reflects diverse earthquake rupture modes with variable recurrence. Stratigraphy and Bayesian analyses of previously reported and new 14C ages in trenches and cores along backthrust scarps in the Seattle fault zone restrict a large earthquake to 1040–910 cal yr B.P. (2σ), a
Authors
Alan R. Nelson, Stephen F. Personius, Brian L. Sherrod, Harvey M. Kelsey, Samuel Y. Johnson, Lee-Ann Bradley, Ray E. Wells
Mammoth Mountain and its mafic periphery—A late Quaternary volcanic field in eastern California
The trachydacite complex of Mammoth Mountain and an array of contemporaneous mafic volcanoes in its periphery together form a discrete late Pleistocene magmatic system that is thermally and compositionally independent of the adjacent subalkaline Long Valley system (California, USA). The Mammoth system first erupted ca. 230 ka, last erupted ca. 8 ka, and remains restless and potentially active. Mag
Authors
Wes Hildreth, Judith Fierstein, Duane E. Champion, Andrew T. Calvert
Advantages of active love wave techniques in geophysical characterizations of seismographic station - Case studies in California and the central and eastern United States
Active-source Love waves, recorded by the multi-channel analysis of surface wave (MASLW) technique, were recently analyzed in two site characterization projects. Between 2010 and 2012, the 2009 American Recovery and Reinvestment Act (ARRA) funded GEOVision to conduct geophysical investigations at 191 seismographic stations in California and the Central Eastern U.S. (CEUS). The original project pla
Authors
Antony Martin, Alan K. Yong, Larry A. Salomone
Pros and cons of rotating ground motion records to fault-normal/parallel directions for response history analysis of buildings
According to the regulatory building codes in the United States (e.g., 2010 California Building Code), at least two horizontal ground motion components are required for three-dimensional (3D) response history analysis (RHA) of building structures. For sites within 5 km of an active fault, these records should be rotated to fault-normal/fault-parallel (FN/FP) directions, and two RHAs should be perf
Authors
Erol Kalkan, Neal S. Kwong
Rocking behavior of an instrumented unique building on the MIT campus identified from ambient shaking data
A state-of-the-art seismic monitoring system comprising 36 accelerometers and a data-logger with real-time capability was recently installed at Building 54 on the Massachusetts Institute of Technology's (MIT) Cambridge, MA, campus. The system is designed to record translational, torsional, and rocking motions, and to facilitate the computation of drift between select pairs of floors. The cast-in-p
Authors
Mehmet Çelebi, Nafi Toksöz, Oral Büyüköztürk
Probing reservoir-triggered earthquakes in Koyna, India, through scientific deep drilling
We report here the salient features of the recently concluded International Continental Scientific Drilling Program (ICDP) workshop in Koyna, India. This workshop was a sequel to the earlier held ICDP workshop in Hyderabad and Koyna in 2011. A total of 49 experts (37 from India and 12 from 8 other countries) spent 3 days reviewing the work carried out during the last 3 years based on the recommend
Authors
H. Gupta, Shailesh Nayak, William L. Ellsworth, Y. J. B. Rao, S. Rajan, B.K. Bansal, N. Purnachandra Rao, S. Roy, K. Arora, R. Mohan, V. M. Tiwari, H. V. S. Satyanarayana, P. K. Patro, D. Shashidhar, K. Mallika
CyberShake-derived ground-motion prediction models for the Los Angeles region with application to earthquake early warning
Real-time applications such as earthquake early warning (EEW) typically use empirical ground-motion prediction equations (GMPEs) along with event magnitude and source-to-site distances to estimate expected shaking levels. In this simplified approach, effects due to finite-fault geometry, directivity and site and basin response are often generalized, which may lead to a significant under- or overes
Authors
Maren Bose, Robert Graves, David Gill, Scott Callaghan, Phillip J. Maechling
Frictional properties of exhumed fault gouges in DFDP-1 cores, Alpine Fault, New Zealand
Principal slip zone gouges recovered during the Deep Fault Drilling Project (DFDP-1), Alpine Fault, New Zealand, were deformed in triaxial friction experiments at temperatures, T, of up to 350°C, effective normal stresses, σn′, of up to 156 MPa, and velocities between 0.01 and 3 µm/s. Chlorite/white mica-bearing DFDP-1A blue gouge, 90.62 m sample depth, is frictionally strong (friction coefficient
Authors
Carolyn Boulton, Diane E. Moore, David A. Lockner, Virginia G. Toy, John Townend, Rupert Southerland