A5060121595- earthquake and tectonic studies
- Geological and Geochemical Analysis
- High-pressure geophysics and materials
- Rock Mechanics and Modeling
- Geotechnical and Geomechanical Engineering
- Hydrocarbon exploration and reservoir analysis
- Seismic Imaging and Inversion Techniques
- Drilling and Well Engineering
- Earthquake Detection and Analysis
- Geological Studies and Exploration
- CO2 Sequestration and Geologic Interactions
- Seismic Waves and Analysis
- Landslides and related hazards
- Hydraulic Fracturing and Reservoir Analysis
- Geological and Geophysical Studies
- Seismology and Earthquake Studies
- Astro and Planetary Science
- Granular flow and fluidized beds
- Metallurgical Processes and Thermodynamics
- Geomagnetism and Paleomagnetism Studies
- Geophysical and Geoelectrical Methods
- High-Velocity Impact and Material Behavior
- Planetary Science and Exploration
- Geochemistry and Geologic Mapping
- Reservoir Engineering and Simulation Methods
Brown University
2016-2025
John Brown University
2012-2023
Woods Hole Oceanographic Institution
2000-2011
Columbia University
2007
Lamont-Doherty Earth Observatory
2007
Deformation experiments have been conducted to investigate the effect of melt fraction and grain size on creep behavior olivine aggregates in diffusion regime. Both nominally melt‐free melt‐added samples display stress exponents ( n = 1.0 ± 0.1) p −3.0 0.5 for melt‐free, −3.2 1.2 melt‐added) indicative boundary creep. The activation energy is 315±35 kJ/mol. An abrupt change rheological partially molten occurs at a 0.05. Below this influence strain rate rather modest. For example, 0.04...
Research Article| November 01, 2001 Strength of slightly serpentinized peridotites: Implications for the tectonics oceanic lithosphere J. Escartín; Escartín 1Laboratoire de Géosciences Marines (CNRS FRE2316), case 89, Institut Physique du Globe Paris, 4 Place Jussieu, 75252 France Search other works by this author on: GSW Google Scholar G. Hirth; Hirth 2Department Geology and Geophysics, Woods Hole Oceanographic Institution, Hole, Massachusetts 02543, USA B. Evans 3Department Earth,...
Experiments have been conducted to investigate the effect of melt on creep behavior water‐free olivine aggregates deformed in dislocation regime. The influence phase is modest at fractions less than ∼0.04. However, > 0.04, rate melt‐added samples enhanced by more an order magnitude relative melt‐free aggregates. This unexpectedly large strain arises because deformation occurs grain boundary sliding (GBS) accommodated a process. Four observations support this hypothesis. (1) enhancement...
Deformation experiments have been conducted to provide constraints on the processes responsible for brittle‐plastic transition in quartz aggregates. A correlation between mechanical behavior and distinctive microstructural characteristics indicates that nonporous quartzite involves at least three transitions deformation mechanism occur with increasing temperature and/or pressure. First there is a from cataclastic faulting semibrittle faulting; observations indicate this occurs due activation...
Several models have been proposed to relate slab geometry parameters such as plate velocity or age. However, studies on the observed relationships between and a wide range of subduction show that there is not simple global relationship any one these other for all zones. Numerical laboratory provide method explore relative importance different physical processes in determining dynamics. Employing 2‐D numerical with viscosity structure constrained by experiments deformation olivine, we dip...
We conducted deformation experiments to investigate the strength, processes, and nature of brittle‐ductile transition lizardite antigorite serpentinites. A from localized distributed occurs as confining pressure increases ∼200 ∼400 MPa at room temperature. Deformation in both brittle (localized) ductile (distributed) regimes is accommodated by shear microcracks, which form preferentially parallel (001) cleavage. Axial microcracks (mode I) are infrequently observed. Volumetric strain...
We present results of a long‐period magnetotelluric (MT) investigation the electrical structure beneath eastern North Pacific. The electric field data consist ∼2 years continuously recorded voltages across an unpowered, ∼4000‐km‐long submarine telephone cable (HAW‐1) extending from Point Arena, California, to Oahu, Hawaii. measurements are coherent some degree with magnetic Honolulu Observatory at periods 0.1 45 days. This coherence is enhanced long over that observed point sensors due...
The electromagnetic data from the Mantle Electromagnetic and Tomography (MELT) experiment are inverted for a two‐dimensional transversely anisotropic conductivity structure that incorporates correction three‐dimensional topographic effects on magnetotelluric responses. model space allows different values in along‐strike, cross‐strike, vertical directions, along with imposed constraints of smoothness closeness among three directions. Anisotropic models provide slightly better fit to given...
We investigate the strength and frictional behavior of olivine aggregates at temperatures effective confining pressures similar to those base seismogenic zone on a typical ridge transform fault. Triaxial compression tests were conducted dry powder (grain size ≤60 μm) between 50 300 MPa (using Argon as pore fluid), 600°C 1000°C, axial displacement rates from 0.06 60 μm/s (axial strain 3 × 10 −6 −3 s −1 ). Yielding shows negative pressure dependence, consistent with predictions for shear...
We evaluate the applicability of plagioclase and gabbro flow laws by comparing predicted observed deformation mechanisms in gabbroic shear zones. Gabbros layered mylonites were collected from Southwest Indian Ridge (SWIR), Ocean Drilling Program Hole 735B. Deformation temperatures are constrained two‐pyroxene thermometry, stress is estimated grain size, analyzed microstructure presence or absence a lattice preferred orientation (LPO). Our analyses indicate that mylonite layers deformed at...