Publications
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Estimating structural collapse fragility of generic building typologies using expert judgment
The structured expert elicitation process proposed by Cooke (1991), hereafter referred to as Cooke's approach, is applied for the first time in the realm of structural collapse-fragility assessment for selected generic construction types. Cooke's approach works on the principle of objective calibration scoring of judgments couple with hypothesis testing used in classical statistics. The performanc
Recurring slope lineae in equatorial regions of Mars
The presence of liquid water is a requirement of habitability on a planet. Possible indicators of liquid surface water on Mars include intermittent flow-like features observed on sloping terrains. These recurring slope lineae are narrow, dark markings on steep slopes that appear and incrementally lengthen during warm seasons on low-albedo surfaces. The lineae fade in cooler seasons and recur over
Authors
Alfred S. McEwen, Colin M. Dundas, Sarah S. Mattson, Anthony D. Toigo, Lujendra Ojha, James J. Wray, Matthew Chojnacki, Shane Byrne, Scott L. Murchie, Nicolas Thomas
What do data used to develop ground-motion prediction equations tell us about motions near faults?
A large database of ground motions from shallow earthquakes occurring in active tectonic regions around the world, recently developed in the Pacific Earthquake Engineering Center’s NGA-West2 project, has been used to investigate what such a database can say about the properties and processes of crustal fault zones. There are a relatively small number of near-rupture records, implying that few reco
Authors
David M. Boore
“Our vanishing glaciers”: One hundred years of glacier retreat in Three Sisters Area, Oregon Cascade Range
In August 1910, thirty-nine members of the Mazamas Mountaineering Club ascended the peaks of the Three Sisters in central Oregon. While climbing, geologist Ira A. Williams photographed the surrounding scenery, including images of Collier Glacier. One hundred years later, U.S. Geological Survey research hydrologist Jim E. O’Connor matched those documented photographs with present day images — the r
Authors
James E. O'Connor
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 denude slopes,
Authors
Richard M. Iverson
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 confirmat
Authors
Ning Lu, Murat Kaya, Jonathan W. Godt
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 are candid
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
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 models an
Authors
Ann M. Ollila, Horton E. Newsom, Benton Clark, Roger C. Wiens, Agnès 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
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