Publications
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Debris flows: Behavior and hazard assessment Debris flows: Behavior and hazard assessment
Debris flows are water-laden masses of soil and fragmented rock that rush down mountainsides, funnel into stream channels, entrain objects in their paths, and form lobate deposits when they spill onto valley floors. Because they have volumetric sediment concentrations that exceed 40 percent, maximum speeds that surpass 10 m/s, and sizes that can range up to ~109 m3, debris flows can...
Authors
Richard M. Iverson
Interrelations among the soil-water retention, hydraulic conductivity, and suction-stress characteristic curves Interrelations among the soil-water retention, hydraulic conductivity, and suction-stress characteristic curves
The three fundamental constitutive relations that describe fluid flow, strength, and deformation behavior of variably saturated soils are the soil-water retention curve (SWRC), hydraulic conductivity function (HCF), and suction-stress characteristic curve (SSCC). Until recently, the interrelations among the SWRC, HCF, and SSCC have not been well established. This work sought experimental
Authors
Ning Lu, Murat Kaya, Jonathan W. Godt
Volatile and organic compositions of sedimentary rocks in Yellowknife Bay, Gale crater, Mars Volatile and organic compositions of sedimentary rocks in Yellowknife Bay, Gale crater, Mars
H2O, CO2, SO2, O2, H2, H2S, HCl, chlorinated hydrocarbons, NO, and other trace gases were evolved during pyrolysis of two mudstone samples acquired by the Curiosity rover at Yellowknife Bay within Gale crater, Mars. H2O/OH-bearing phases included 2:1 phyllosilicate(s), bassanite, akaganeite, and amorphous materials. Thermal decomposition of carbonates and combustion of organic materials...
Authors
D. W. Ming, P.D. Archer, D.P. Glavin, J.L. Eigenbrode, H.B. Franz, B. Sutter, A.E. Brunner, J. C. Stern, C. Freissinet, A.C. McAdam, P.R. Mahaffy, M. Cabane, P. Coll, J.L. Campbell, S.K. Atreya, P.B. Niles, J.F. Bell, D.L. Bish, W.B. Brinckerhoff, A. Buch, P.G. Conrad, D.J. Des Marais, B.L. Ehlmann, A.G. Fairén, K. Farley, G.J. Flesch, P. Francois, Ralf Gellert, J. A. Grant, J.P. Grotzinger, S. Gupta, Kenneth E. Herkenhoff, J.A. Hurowitz, L.A. Leshin, K.W. Lewis, S. M. McLennan, Karl E. Miller, J. Moersch, R.V. Morris, R. Navarro- González, A.A. Pavlov, G.M. Perrett, I. Pradler, S. W. Squyres, Roger E. Summons, A. Steele, E.M. Stolper, D.Y. Sumner, C. Szopa, S. Teinturier, M.G. Trainer, A.H. Treiman, D. T. Vaniman, A.R. Vasavada, C.R. Webster, J.J. Wray, R.A. Yingst
Trace element geochemistry (Li, Ba, Sr, and Rb) using Curiosity's ChemCam: early results for Gale crater from Bradbury Landing Site to Rocknest Trace element geochemistry (Li, Ba, Sr, and Rb) using Curiosity's ChemCam: early results for Gale crater from Bradbury Landing Site to Rocknest
The ChemCam instrument package on the Mars rover, Curiosity, provides new capabilities to probe the abundances of certain trace elements in the rocks and soils on Mars using the laser-induced breakdown spectroscopy technique. We focus on detecting and quantifying Li, Ba, Rb, and Sr in targets analyzed during the first 100 sols, from Bradbury Landing Site to Rocknest. Univariate peak area...
Authors
Ann M. Ollila, Horton E. Newsom, Benton Clark, Roger C. Wiens, Agnes Cousin, Jen G. Blank, Nicolas Mangold, Violaine Sautter, Sylvestre Maurice, Samuel M. Clegg, Olivier Gasnault, Olivier Forni, Robert Tokar, Eric Lewin, M. Darby Dyar, Jeremie Lasue, Ryan Anderson, Scott M. McLennan, John Bridges, Dave Vaniman, Nina Lanza, Cecile Fabre, Noureddine Melikechi, Glynis M. Perett, John L. Campbell, Penelope L. King, Bruce Barraclough, Dorothea Delapp, Stephen Johnstone, Pierre-Yves Meslin, Anya Rosen-Gooding, Josh Williams
Annual and seasonal distribution of intertidal foraminifera and stable carbon isotope geochemistry, Bandon Marsh, Oregon, USA 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...
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 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...
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 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 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...
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 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...
Authors
Alan R. Nelson, Stephen F. Personius, Brian L. Sherrod, Harvey M. Kelsey, Samuel Y. Johnson, Lee-Ann Bradley, Ray E. Wells
CyberShake-derived ground-motion prediction models for the Los Angeles region with application to earthquake early warning 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-...
Authors
Maren Bose, Robert Graves, David Gill, Scott Callaghan, Phillip J. Maechling
Predicting the spatial extent of liquefaction from geospatial and earthquake specific parameters Predicting the spatial extent of liquefaction from geospatial and earthquake specific parameters
The spatially extensive damage from the 2010-2011 Christchurch, New Zealand earthquake events are a reminder of the need for liquefaction hazard maps for anticipating damage from future earthquakes. Liquefaction hazard mapping as traditionally relied on detailed geologic mapping and expensive site studies. These traditional techniques are difficult to apply globally for rapid response or...
Authors
Jing Zhu, Laurie G. Baise, Eric M. Thompson, David J. Wald, Keith L. Knudsen
Latest Quaternary paleoseismology and evidence of distributed dextral shear along the Mohawk Valley fault zone, northern Walker Lane, California Latest Quaternary paleoseismology and evidence of distributed dextral shear along the Mohawk Valley fault zone, northern Walker Lane, California
The dextral-slip Mohawk Valley fault zone (MVFZ) strikes northwestward along the eastern margin of the Sierra Nevada in the northern Walker Lane. Geodetic block modeling indicates that the MVFZ may accommodate ~3 mm/yr of regional dextral strain, implying that it is the highest slip-rate strike-slip fault in the region; however, only limited geologic data are available to constrain the...
Authors
Ryan D. Gold, Richard W. Briggs, Stephen Personius, Anthony J. Crone, Shannon A. Mahan, Stephen Angster