A5073557562- earthquake and tectonic studies
- Geological and Geochemical Analysis
- High-pressure geophysics and materials
- Seismology and Earthquake Studies
- Geological Studies and Exploration
- Geophysics and Gravity Measurements
- Earthquake Detection and Analysis
- Seismic Waves and Analysis
- Methane Hydrates and Related Phenomena
- GNSS positioning and interference
- Geology and Paleoclimatology Research
- Cryospheric studies and observations
- Geological and Geophysical Studies
- Landslides and related hazards
- Hydrocarbon exploration and reservoir analysis
- Geochemistry and Geologic Mapping
- Seismic Imaging and Inversion Techniques
- Geological Modeling and Analysis
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Geological and Tectonic Studies in Latin America
- Geotechnical and Geomechanical Engineering
- Atmospheric and Environmental Gas Dynamics
- Geomagnetism and Paleomagnetism Studies
- Climate change and permafrost
- Inertial Sensor and Navigation
Michigan State University
2019-2025
Leibniz Institute of Freshwater Ecology and Inland Fisheries
2024
University of Alaska Fairbanks
2012-2022
Utrecht University
2021
Alaska Volcano Observatory
2006-2018
National Astronomical Observatory of Japan
2014
Association for the Development of Earthquake Prediction
2014
The University of Tokyo
2014
UNSW Sydney
2013-2014
Kyoto University
2014
Global Positioning System (GPS) measurements in China indicate that crustal shortening accommodates most of India's penetration into Eurasia. Deformation within the Tibetan Plateau and its margins, Himalaya, Altyn Tagh, Qilian Shan, absorbs more than 90% relative motion between Indian Eurasian plates. Internal plateau itself accounts for one-third total convergence. However, south Kunlun Ganzi-Mani faults is moving eastward to both India This movement accommodated through rotation material...
The MW (moment magnitude) 7.9 Denali fault earthquake on 3 November 2002 was associated with 340 kilometers of surface rupture and the largest strike-slip in North America almost 150 years. It illuminates mechanics hazards large faults. began thrusting previously unrecognized Susitna Glacier fault, continued right-slip then took a right step Totschunda fault. There is good correlation between geologically observed geophysically inferred moment release. produced unusually strong distal...
We analyze continuous GPS measurements in Nepal, southern side of the Himalaya, and compare results with GRACE observations this area. find both show significant seasonal variations. Further comparison indicates that observed height variation GRACE‐derived vertical displacement due to changing hydrologic load exhibit very consistent results, for amplitude phase. For stations whose observation time span are longer than 3 years, average WRMS reduction is ∼45% when we subtract displacements...
For the last decade, it has been known that reflected GPS signals observed with specialized instruments could be used to measure sea level. In this letter, data from an existing geodetic-quality site near Kachemak Bay, Alaska, are analyzed for a one-year time period. Daily sea-level variations more than 7 m. Tidal coefficients have estimated and compared records traditional tide gauge at Seldovia Harbor, <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML"...
We use geodetic techniques to study the India‐Eurasia collision zone. Six years of GPS data constrain maximum surface contraction rates across Nepal Himalaya 18 ± 2 mm/yr at 12°N ±13° (1σ). These 150‐km‐wide deforming zone are well fitted with a dislocation model buried north dipping detachment fault striking 105°, which aseismically slips rate 20 1 mm/yr, our preferred estimate for India‐to‐southern‐Tibet convergence rate. This is in good agreement various geologic predictions 7 Himalaya. A...
We have analyzed 204 days of Global Positioning System (GPS) data from the global GPS network spanning January 1991 through March 1996. On basis these coordinate solutions, we estimated velocities for 38 sites, mostly located on interiors Africa, Antarctica, Australia, Eurasia, Nazca, North America, Pacific, and South America plates. The uncertainties horizontal velocity components range 1.2 to 5.0 mm/yr. With exception sites Pacific Nazca plates, agree with absolute plate model predictions...
We developed a 3‐D viscoelastic model, in concert with an afterslip to describe the postseismic deformation following 1964 Alaska earthquake. Our model incorporates realistic geometry including elastic slab very low dip angle. These geometric factors are important and require reanalysis of coseismic model. differs from previous models that Montague Island splay fault extends farther along Kenai Peninsula coast, as result, slip on megathrust region is smaller. computed using range mantle...
During the first 2 years following 2002 M w = 7.9 Denali, Alaska, strike‐slip earthquake, a large array of Global Positioning System (GPS) receivers recorded rapid postseismic surface motions extending at least 300 km from rupture and rates more than 100 mm/yr in near field. Here we use three‐dimensional (3‐D) viscoelastic finite element models to infer mechanisms responsible for these observations. We consider afterslip both an inversion GPS displacements stress‐driven forward models,...
We use data from campaign and continuous GPS sites in southeast Alaska the neighboring region of Canada to constrain a regional tectonic block model that estimates angular velocities derives self‐consistent set fault slip rates motions. Present‐day tectonics is strongly influenced by collision Yakutat block. Our predicts velocity 50.3 ± 0.8 mm/a toward N22.9 0.6° W for results suggest eastern edge deforming. Along this edge, Fairweather accommodates large portion Pacific‐North America...
Repeated geodetic measurements with the Global Positioning System (GPS) provide direct of displacements due to plate motions and active crustal deformation in Central America northern South America, an area complex interaction Nazca, Cocos, Caribbean American plates. The displacement rates for period 1988–1991, obtained from results first three And (CASA) GPS campaigns, are general agreement predictions NUVEL‐1 motion model, but there differences detail between observations model....
We compare vertical seasonal loading deformation observed by continuous GPS stations in southern Alaska and modeled displacements due to hydrological inferred from GRACE. Seasonal are significant, GPS‐observed GRACE‐modeled highly correlated. define a measure called the WRMS Reduction Ratio fraction of position variations at periods removed correcting time series using model based on The median is 0.82 mean 0.73 ± 0.26, with value 1.0 indicating perfect agreement effects atmosphere non‐tidal...
Abstract Understanding of postseismic deformation following great subduction zone earthquakes is complicated by the combined effects viscoelastic relaxation earthquake‐induced stresses in upper mantle and time‐dependent afterslip on megathrust. We integrate geodetic observations constraints from small repeating megathrust to better distinguish contributions these two processes. have developed a three‐dimensional, spherical finite element model study 2011 M w 9.0 Tohoku earthquake that has...
Abstract We find seasonal horizontal crustal motions observed by GPS positioning in elastic response to heavy rainfall the Amazon Basin and monsoons Southeast Asia be consistent with those inferred from Gravity Recovery Climate Experiment (GRACE) gravity observations of water mass loading. Solid Earth moves toward during spring summer back away these areas 6 months later when load is minimum. Vertical oscillations GRACE are 2 3 times larger than oscillation near margins large Some...
Abstract We resurveyed preexisting campaign Global Positioning System (GPS) sites and estimated a highly precise GPS velocity field for the Alaska Peninsula. use TDEFNODE software to model slip deficit distribution using new velocities. find systematic misfits vertical velocities from optimal that fits horizontal well, which cannot be explained by altering distribution, so we only in study. Locations of three boundaries mark significant along‐strike change locking are identified. The Kodiak...