A5084869623- earthquake and tectonic studies
- Geological and Geochemical Analysis
- High-pressure geophysics and materials
- Geology and Paleoclimatology Research
- Seismic Imaging and Inversion Techniques
- Geological formations and processes
- Seismic Waves and Analysis
- Hydraulic Fracturing and Reservoir Analysis
- Drilling and Well Engineering
- Geological and Geophysical Studies
- Geochemistry and Geologic Mapping
- Geological Studies and Exploration
- Geological Modeling and Analysis
- Seismology and Earthquake Studies
- Landslides and related hazards
- Geophysical Methods and Applications
- Hydrocarbon exploration and reservoir analysis
- Geophysics and Gravity Measurements
- Reservoir Engineering and Simulation Methods
- Geophysics and Sensor Technology
- Geotechnical and Geomechanical Engineering
- Rock Mechanics and Modeling
- Radioactive contamination and transfer
- Ecology and Vegetation Dynamics Studies
- Earthquake Detection and Analysis
Los Alamos National Laboratory
2013-2023
Los Alamos National Security (United States)
2020
Cytel (United States)
2020
University of Graz
2011
University of Washington
2010
University of Oregon
2002-2007
The University of Texas at El Paso
2001-2003
Sandia National Laboratories
2003
University of Arizona
1994-1999
The University of Adelaide
1997-1998
Research Article| July 01, 2010 Small-scale convection at the edge of Colorado Plateau: Implications for topography, magmatism, and evolution Proterozoic lithosphere J.W. van Wijk; Wijk * 1Department Earth Atmospheric Sciences, University Houston, 312 Science Bldg. 1, Texas 77204, USA *E-mail: jwvanwijk@uh.edu. Search other works by this author on: GSW Google Scholar W.S. Baldridge; Baldridge 2Earth Environmental Sciences Division, Los Alamos National Laboratory, Alamos, New Mexico 87545, J....
The correspondence between seismic velocity anomalies in the crust and mantle differential incision of continental-scale Colorado River system suggests that significant mantle-to-surface interactions can take place deep within continental interiors. Rocky Mountain region exhibits low-seismic-velocity associated with atypically high (and rough) topography, steep normalized river segments, areas greatest incision. Thermochronologic geologic data show regional exhumation accelerated starting...
Research Article| November 01, 2008 Model for tectonically driven incision of the younger than 6 Ma Grand Canyon Karl E. Karlstrom; Karlstrom * 11Department Earth and Planetary Sciences, University New Mexico, Albuquerque, 87131, USA *E-mail: kek1@unm.edu. Search other works by this author on: GSW Google Scholar Ryan Crow; Crow L.J. Crossey; Crossey D. Coblentz; Coblentz 22Geodynamics Group, Los Alamos National Laboratory, Alamos, 87545, J. W. Van Wijk Geology (2008) 36 (11): 835–838....
The relative contribution of topographic (e.g., ridge push, continental margins, and elevated crust) plate boundary subduction collisional) forces to the intraplate stress field in Indo‐Australian (IAP) is evaluated through a finite element analysis. Two important aspects IAP are highlighted present study: (1) if substantial focusing push torque occurs along collisional boundaries (i.e., Himalaya, New Guinea, Zealand), many first‐order features observed can be explained without appealing...
Abstract The in situ stress field of south‐eastern Australia inferred from earthquake focal mechanisms and bore‐hole breakouts is unusual that it characterised by large obliquity between the maximum horizontal compressive orientation ( S Hmax ) absolute plate motion azimuth. evolution neotectonic strain deduced historical seismicity both onshore offshore faulting records used to address origin this field. Strain rates derived estimates seismic moment release rate (up ∼10 −16 s −1 are...
Interest and controversy exist on the origin of forces that move tectonically deform plates, especially regarding relative importance loads applied to plate margins base those created internally (e.g., by elevated potential energy in uplifted regions). To quantify these loads, we evaluate predicted interplate stress through two‐dimensional finite element analysis North American plate, finding boundary are most important, followed internal basal loads. Craton root drag ∼4 MPa opposes absolute...
Abstract Aim Topography is a fundamental geophysical observable that contains valuable information about the geodynamic, tectonic and climatic history of region. Here, we extend traditional uses topographic analysis to evaluate role played by topography in distribution regional‐scale biodiversity south‐western USA. An important aspect our study its ability provide way quantify characteristics fabric construct predictive models can be used test hypotheses relate biodiversity. Location...
The first‐order South American intraplate stress field was modeled through a finite element analysis to evaluate the relative contribution of plate boundary forces and sources. mesh consisted 3100 nodes in network 5993 equal‐area triangular elements which provided spatial resolution about 1° at equator. An important aspect our modeling is inclusion topographic due cooling oceanic lithosphere along Mid‐Atlantic Ridge (e.g., ridge push), continental margins east coast Brazil Argentina,...
Recent reports that TLR4 and TLR7 ligands can synergistically trigger Th1 biased immune responses suggest an adjuvant contains both would be excellent candidate for co-administration with vaccine antigens which heavily are desired. Ligands of each these TLRs generally have disparate biochemical properties, however, straightforward co-formulation may represent obstacle. We show here the ligand, imiquimod, GLA, in human whole blood. combined anionic liposomal formulation where ligand is...
The tectonic forces controlling the present‐day regional intraplate stress field in continental Australia have been evaluated through a finite element analysis of stresses Indo‐Australian plate (IAP). Constraint for modeling is provided by an observed based on observations 12 provinces. A weighted “basis set” method has employed to provide efficient means evaluate very large number force combinations and make quantitative assessment fit between predicted fields. Our results indicate that...
The mean potential energy of the lithosphere is useful for defining tectonic reference state (TRS) Earth and can be used to constrain ambient stress in plates. In absence external forces applied at base or along plate boundaries a lithospheric column with TRS would remain undeformed. Thus difference between determines whether an extensional, joeutral, compressional stress. We evaluate intraplate variations about this mean, using simple, first‐order density model. This model assumed that...
Research Article| September 01, 1994 Tectonic stresses in the African plate: Constraints on ambient lithospheric stress state David D. Coblentz; Coblentz 1Department of Geosciences, University Arizona, Tucson, Arizona 85721 Search for other works by this author on: GSW Google Scholar Mike Sandiford 2Department Geology, Adelaide, Adelaide 5005, Australia Author and Article Information Publisher: Geological Society America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print 0091-7613...
Abstract During an excavation in the 1970s, a disarticulated female human skeleton, later nicknamed Luzia, was discovered at 12m depth Lapa Vermelha rockshelter central Brazil. Radiocarbon dating of associated charcoal suggested age 11.4‐16.4 ka for skeleton. The scattering skeletal parts, some uncertainty about exact provenience and evidence pervasive insect turbation archaeological layers have raised doubts accuracy age. Luminescence dates depositional ages sediments are reported here....
New cosmogenic burial and published dates of Colorado Green river terraces are used to infer variable incision rates along the rivers in past 10 Ma. A knickpoint at Lees Ferry separates lower upper River basins. We obtained an isochron date 1.5 ± 0.13 Ma on a 190-m-high strath terrace near Bullfrog Basin, Utah (upstream Ferry). This age yields average rate 126 +12/–10 m/Ma above is three times older than surface same terrace, suggesting that inferred by exposure dating may be minimum ages....
Numerical stress models suggest that gravitational body forces associated with elevated topography around sedimentary basins can significantly influence the and strain pattern in basin interiors. In absence of tectonic forces, surrounded by high‐altitude mountain ranges experience net horizontal compression. Owing to pointing from areas high potential energy subsided areas, further lithospheric extension eventually terminate, leading a gradual late stage inversion entire system. Modeling...
The World Stress Map (WSM) database contains thousands of intraplate stress indicators, with the potential to provide important constraint for arguments about relationship between tectonic stresses and both kinematics dynamics plate motion. Previous studies, which relied almost exclusively on visual inspection data, established existence broad regions uniform maximum horizontal compressive orientation ( S H max ) regimes a regional scale. In present study, we statistical analysis WSM...
Abstract Aim To evaluate the hypothesis that geomorphometric parameters of upper montane Andean environments have an important influence on regional fire ecology and consequently play a role in spatial distribution ‘remnant’ tree islands dominated by Polylepis . Location A glacial landscape located between 3600 4400 m elevation Cajas National Park, south‐western Ecuador. Methods The eigenvalue ratio method was used to 30‐m digital model for Park. character evaluated quantifying topographic...
Abstract Lack of consideration the geomechanical interaction between salt bodies and surrounding formations has led to documented drilling failures adjacent diapirs1–3, in some cases resulting individual well abandonment costs tens millions dollars. To address this issue, a three-dimensional non-linear finite element simulation effort was initiated analyze situ stress state existing before as under producing conditions. This work leverages unique expertise mechanics computational modeling....
Regions of high topography which exhibit both compressional and extensional deformation provide a natural laboratory to place constraints on horizontal intraplate stress magnitudes. An elastic finite element analysis the lithospheric field in Cordillera Bianca region Peru has been used evaluate state constrain South American The orthogonal orientation Andean east–west regional conjunction with well‐documented change style from compression extension across provides unique setting for...
Uplift or reduced subsidence prior to continental breakup is a key component of the rift-drift transition. This uplift causes lateral variations in lithospheric potential energy, which can increase intraplate deviatoric tension, thereby facilitating rupture. There growing body evidence that pre-breakup global phenomenon characteristic magmatic and magma-poor rifted margins. Evidence provided by subaerial extrusion lava interpreted from drill logs, stratigraphic records, presence...