A5008198868- earthquake and tectonic studies
- Methane Hydrates and Related Phenomena
- Seismic Imaging and Inversion Techniques
- Geological and Geochemical Analysis
- High-pressure geophysics and materials
- Seismology and Earthquake Studies
- Seismic Waves and Analysis
- Geological and Geophysical Studies
- Hydrocarbon exploration and reservoir analysis
- Drilling and Well Engineering
- Geological formations and processes
- Reservoir Engineering and Simulation Methods
- Geology and Paleoclimatology Research
- Earthquake Detection and Analysis
- Hydraulic Fracturing and Reservoir Analysis
- Geological Modeling and Analysis
- Landslides and related hazards
- Geological Studies and Exploration
- Geological and Tectonic Studies in Latin America
- Rock Mechanics and Modeling
- Geotechnical and Geomechanical Engineering
- Tunneling and Rock Mechanics
- Atmospheric and Environmental Gas Dynamics
- Groundwater flow and contamination studies
- Geotechnical Engineering and Underground Structures
The University of Texas at Austin
2020-2025
Pennsylvania State University
2014-2023
University of Texas Institute for Geophysics
2019-2023
International Ocean Discovery Program
2017-2020
Kai Research (United States)
2020
Expedition (United Kingdom)
2019
Japan Agency for Marine-Earth Science and Technology
2011-2019
Universidad de Granada
2019
Oregon State University
2019
Instituto Andaluz de Ciencias de la Tierra
2019
At subduction zones, fluid flow, pore pressure, and tectonic processes are tightly interconnected. Excess pressure is driven by loading fluids released mineral dehydration, it has profound effects on fault earthquake mechanics through its control effective stress. The egress of these overpressured fluids, which in part governed the presence permeable a primary mechanism volatile solute transport to oceans. Recent field measurements, new constraints gained from laboratory studies, numerical...
Research Article| February 01, 2001 Updip limit of the seismogenic zone beneath accretionary prism southwest Japan: An effect diagenetic to low-grade metamorphic processes and increasing effective stress J. Casey Moore; Moore 1Department Earth Sciences, University California, Santa Cruz, California 95064, USA Search for other works by this author on: GSW Google Scholar Demian Saffer Author Article Information Publisher: Geological Society America Received: 05 Jul 2000 Revision 03 Nov...
[1] The slip behavior of major faults depends largely on the frictional and hydrologic properties fault gouge. We report laboratory experiments designed to measure strength, friction constitutive properties, permeability a suite saturated clay-rich gouges, including: 50:50% mixture montmorillonite-quartz, powdered illite shale, chlorite schist. Friction measurements indicate that gouges are consistently weak, with steady state coefficient sliding <0.35. montmorillonite gouge (μ = 0.19–0.23)...
Abstract Slow earthquakes represent an important conundrum in earthquake physics. While regular are catastrophic events with rupture velocities governed by elastic wave speed, the processes that underlie slow fault slip phenomena, including recent discoveries of tremor, slow-slip and low-frequency earthquakes, less understood. Theoretical models sparse laboratory observations have provided insights, but physics remain enigmatic. Here we report on illuminate mechanics phenomena. We show a...
Research Article| January 01, 2011 On the relation between fault strength and frictional stability Matt J. Ikari; Ikari Department of Geosciences, Pennsylvania State University, University Park, 16802, USA Search for other works by this author on: GSW Google Scholar Chris Marone; Marone Demian M. Saffer Author Article Information Publisher: Geological Society America Received: 26 May 2010 Revision 12 Aug Accepted: 23 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print 0091-7613 © Geology...
Eight slow-slip events over 6 years accommodated up to 50% of the fault slip on Nankai megathrust.
The Nankai Trough accretionary prism is considered an “end‐member” accreting a coarse terrigenous sediment section in setting with structural simplicity, unparalleled resolution by seismic and other geophysical techniques, large historic earthquakes. It therefore has been the focus of Ocean Drilling Program (ODP) drilling to address several unresolved questions concerning processes evolution. At six sites cored along two transects across during ODP Leg 190, lithostratigraphy diagenesis vary...
We report on laboratory experiments examining the effect of hydration state frictional properties simulated clay and quartz fault gouge. tested four mixtures Ca‐montmorillonite (100, 70, 50, 30% montmorillonite) at states: dry (<4.50 wt% water), one water interlayer equivalent (4.5–8.7 two layers (8.7–16.0 three layer (>16.0 water). controlled using either oven drying (for <13 H 2 O) or saline solutions (to achieve >13 O under conditions relative humidity). For each clay/quartz...
Research Article| August 01, 2009 Elevated fluid pressure and extreme mechanical weakness of a plate boundary thrust, Nankai Trough subduction zone Harold J. Tobin; Tobin * 1Department Geology Geophysics, University Wisconsin–Madison, Madison, Wisconsin 53706, USA *E-mail: htobin@wisc.edu. Search for other works by this author on: GSW Google Scholar Demian M. Saffer 2Department Geosciences, The Pennsylvania State University, Park, 16802, Author Article Information Publisher: Geological...
Recent seismic reflection and ocean bottom seismometer (OBS) studies reveal broad regions of low velocity along the Nankai subduction plate boundary megathrust offshore SW Japan. These zones (LVZ's) extend ∼55 km landward from trench, corresponding to depths >∼10 below sea floor. Here, we estimate in‐situ pore pressure stress state within these LVZ's by combining P‐wave velocities obtained geophysical surveys with new well‐constrained empirical relations between velocity, porosity,...
Stressed Out Large seismic events such as the 2011 magnitude 9.0 Tohoku-Oki earthquake can have profound effects not just on severity of ground motion and tsunami generation, but also overall state crust in surrounding regions. Lin et al. (p. 687 ) analyzed stress 1 year after compared it with estimated before earthquake. In situ resistivity images were from three boreholes drilled into across plate interface where occurred. Stress values indicate a nearly complete drop following that type...
Slow slip events (SSEs) accommodate a significant proportion of tectonic plate motion at subduction zones, yet little is known about the faults that actually host them. The shallow depth (<2 km) well-documented SSEs Hikurangi zone offshore New Zealand offers unique opportunity to link geophysical imaging with direct access incoming material represents megathrust fault rocks hosting slow slip. Two recent International Ocean Discovery Program Expeditions sampled this before it entrained...
Abstract We present results from a comprehensive laboratory study of the frictional strength and constitutive properties for all three active strands San Andreas Fault penetrated in Observatory at Depth (SAFOD). The SAFOD borehole Southwest Deforming Zone (SDZ), Central (CDZ), both which are actively creeping, Northeast Boundary (NBF). Our include measurements cuttings core samples recovered depths ~2.7 km. find that materials two creeping faults exhibit low strengths ( μ = ~0.1),...
Earthquakes occur by overcoming fault friction; therefore, quantifying resistance is central to earthquake physics. Values for both static and dynamic friction are required, the latter especially difficult determine on natural faults. However, large earthquakes provide signals that can in situ. The Japan Trench Fast Drilling Project (JFAST), an Integrated Ocean Discovery Program expedition, determined stresses collecting data directly from 1–2 years after 2011 M w 9.1 Tohoku earthquake....
Plate motion on shallow subduction megathrusts is accommodated by a spectrum of tectonic slip modes. However, the frictional properties and conditions that sustain these diverse behaviors remain enigmatic. Frictional healing one such property, which describes degree fault restrengthening between earthquakes. We show rate materials entrained along megathrust at northern Hikurangi margin, hosts well-characterized recurring slow events (SSEs), nearly zero (<0.0001 per decade). These low rates...