A5085102733- Seismology and Earthquake Studies
- earthquake and tectonic studies
- Seismic Waves and Analysis
- Seismic Imaging and Inversion Techniques
- GNSS positioning and interference
- Earthquake Detection and Analysis
- Drilling and Well Engineering
- Inertial Sensor and Navigation
- Geophysics and Sensor Technology
- Geology and Paleoclimatology Research
- Hydraulic Fracturing and Reservoir Analysis
- Geophysics and Gravity Measurements
- Astronomical Observations and Instrumentation
- High-pressure geophysics and materials
- Geological Modeling and Analysis
- Geological formations and processes
- Geochemistry and Geologic Mapping
- Advanced Computational Techniques and Applications
- Methane Hydrates and Related Phenomena
- Landslides and related hazards
- Geological and Geochemical Analysis
- Geophysical Methods and Applications
- Scientific Computing and Data Management
- Marine and environmental studies
- Semantic Web and Ontologies
Sandia National Laboratories
2022-2024
UNAVCO
2012-2022
Nautilus (United States)
2012-2019
GNS Science
2000
The positions of 115 ground marks in a 150 × 100 km area oblique continental collision the central Southern Alps, New Zealand, have been measured by Global Positioning System (GPS) two to four times between 1994 and 1998. Contemporary velocity strain rate fields derived from these observations are largely invariant along northeasterly strike mountains Alpine fault. Across strike, more than 60% occurs within band 5 NW 20 SE fault, but significant continues at least further 60 near edge Alps...
In 1954, four earthquakes of M > 6.0 occurred within a 30 km radius in period six months. The Rainbow Mountain‐Fairview Peak‐Dixie Valley are among the largest to have been recorded geodetically Basin and Range province. Fairview Peak earthquake (M = 7.2, December 12, 1954) followed two events Mountains ( 6.2, July 6, 6.5, August 24, by 6 Four minutes later Dixie fault ruptured 6.7, 1954). changes static stresses caused calculated using Coulomb‐Navier failure criterion assuming uniform...
The Plate Boundary Observatory, the geodetic component of EarthScope program, includes 74 borehole strainmeters installed in western United States and on Vancouver Island, Canada. In this study, we calibrate 45 instruments by comparing observed M 2 O 1 Earth tides with those predicted using tide models. For each strainmeter, invert for a coupling matrix that relates gauge measurements to regional strain field assuming only measured strains are linear combinations areal shear strains. We...
Since July 1994 an unusually persistent swarm of earthquakes ( M <4.0) has been in progress at the Hengill triple junction, SW Iceland. Activity is clustered around center Hrómundartindur volcanic system. Geodetic measurements indicate a few centimeters uplift and expansion area, consistent with pressure source 6.5±3 km depth beneath The system within stress field south Iceland transform zone, majority recorded represent strike‐slip faulting on subvertical planes. We show that secondary...
Research Article| October 03, 2018 Development of a Geodetic Component for the U.S. West Coast Earthquake Early Warning System J. R. Murray; Murray aU.S. Geological Survey, 345 Middlefield Road, MS 977, Menlo Park, California 94025 U.S.A., jrmurray@usgs.gov Search other works by this author on: GSW Google Scholar B. W. Crowell; Crowell bDepartment Earth and Space Sciences, University Washington, Johnson Hall Room‐070, Box 351310, 4000 15th Avenue NE, Seattle, Washington 98195 U.S.A....
Research Article| February 14, 2018 TLALOCNet: A Continuous GPS‐Met Backbone in Mexico for Seismotectonic and Atmospheric E. Cabral‐Cano; Cabral‐Cano aUniversidad Nacional Autónoma de México, Instituto Geofísica, Ciudad Universitaria, City, CDMX 04510, Mexico, ecabral@geofisica.unam.mx Search other works by this author on: GSW Google Scholar X. Pérez‐Campos; Pérez‐Campos B. Márquez‐Azúa; Márquez‐Azúa bUniversidad Guadalajara, Centro Estudios Estratégicos para el Desarrollo, Tomás V. Gómez...
Abstract With increasing geophysical applications using distributed acoustic sensing (DAS) technology, there is a need to implement metadata standard specifically for DAS facilitate the integration of measurements across experiments and increase reusability. We propose intended primarily research community, which fully describes five key components experiment: (1) interrogator; (2) data acquisition; (3) channels; (4) cable; (5) fiber. The proposed schema, overall structure metadata,...
Abstract A previous geodetic estimate of 18 mm/yr horizontal extension for the Taupo Volcanic Zone (TVZ) immediately north Lake period 1949–86 is re‐examined several reasons: this rate has not been confirmed by GPS surveys in 1990s; newly compiled precise levelling data now allow us to extent non‐tectonic deformation attributable Wairakei geothermal field; and lake‐levelling reveal a spatial variation tectonic subsidence that casts doubt on earlier assumption homogeneous strain. We use...
Abstract During February 2023, a total of 32 individual distributed acoustic sensing (DAS) systems acted jointly as global seismic monitoring network. The aim this Global DAS Month campaign was to coordinate diverse network organizations, instruments, and file formats gain knowledge move toward the next generation earthquake networks. campaign, 156 earthquakes magnitude 5 or larger were reported by U.S. Geological Survey contributors shared data for 60 min after each event’s origin time....
Abstract Regional networks of Global Navigation Satellite System (GNSS) stations cover seismically and volcanically active areas throughout the United States. Data from these have been used to produce high-precision, three-component velocity fields covering broad geographic regions as well position time series that track time-varying crustal deformation. This information has contributed assessing interseismic strain accumulation related seismic hazard, revealed previously unknown occurrences...
Abstract Several studies have shown that real-time (RT) Global Navigation Satellite Systems (GNSS) measurements can provide an estimate of earthquake’s moment magnitude (Mw) using scaling laws relate peak ground displacements (PGDs) and hypocentral distance with Mw. In this study, we use data from GNSS stations operated by UNAVCO as part the National Science Foundation Geodetic Facility for Advancement Geoscience (GAGE) comprises Network Americas (NOTA) to show precise point positioning...
Abstract The July 2019 Ridgecrest sequence was observed in exquisite detail by the National Science Foundation’s (NSF) Geodetic Facility for Advancement of Geoscience (GAGE) Network Americas (NOTA), which has a dense array continuously observing Global Navigation Satellite System (GNSS) stations and subarrays strain seismic borehole networks southern California. Two hundred eighteen GNSS 10 NOTA within 250 km epicentral area recorded sequence. Special downloads high-rate data from sites...
Abstract Rapid earthquake magnitude estimation from real-time space-based geodetic observation streams provides an opportunity to mitigate the impact of large and potentially damaging earthquakes by issuing low-latency warnings prior any significant destructive shaking. Geodetic contributions characterization rapid have evolved in last 20 yr, post-processed seismic waveforms to, more recently, improved capacity regional networks enabled Global Navigation Satellite System seismology using...
In 1954, four earthquakes greater than M s = 6.0 occurred within a 30‐km radius and in period of 6 months. Elevation angle changes calculated from repeated leveling triangulation surveys which span the coseismic provide constraints on fault geometries slip faults were activated. The quality geodetic data is assessed. Corrections are applied to for subsidence due groundwater withdrawal Fallon area, rod miscalibration error 150 ± 30 ppm isolated made 1967. observations then simultaneously...
For the strainmeter component of Plate Boundary Observatory, filters are needed to produce low-frequency series (5-minute samples) from higherfrequency (1 Hz) data generated by instruments.We present design methods for finding that efficient, causal, and compact.We use standard generating symmetric finite impulse response filters, followed root finding, selection roots, reconstruction weights, using procedures make these processes numerically stable.The final show appropriate performance...
Repeated GPS measurements at 21 sites along a profile extending 100 km southeast of the Alpine Fault demonstrate that active deformation occurs across much South Island New Zealand and slip on cannot accommodate all Pacific‐Australian plate motion. Projecting velocity field as normal parallel components to Fault, shows fault‐parallel component motion falls characteristic dislocation curve suggests elastic strain accumulation in upper crust. This type is associated with deep aseismic ductile...
UNAVCO is a National Science Foundation (NSF) funded consortium that facilitates geoscience research and education using geodesy. It responsible for the collection, archiving distribution of data from GPS sites installed in every continent world. In addition to data, collects borehole seismic, strain meter, meteorological, digital imagery data. One UNAVCO's largest programs Plate Boundary Observatory (PBO), geodetic component NSF Earth scope program. PBO consists over 1100 continuous plus 80...
We seek to restore the integrity of geodetic network in San Fernando, Simi, Santa Clarita Valleys and northern Los Angeles Basin by remeasurement identification BMs which experienced non-tectonic displacements associated with Northridge earthquake. then use observed displacement portray or predict permanent vertical horizontal deformation 1994 earthquake throughout area, including sites where we lack measurements. To accomplish this, find fault geometry slip that are most compatible...
[1] The Plate Boundary Observatory, the geodetic component of EarthScope program, includes 74 borehole strainmeters installed in western United States and on Vancouver Island, Canada. In this study, we calibrate 45 instruments by comparing observed M2 O1 Earth tides with those predicted using tide models. For each strainmeter, invert for a coupling matrix that relates gauge measurements to regional strain field assuming only measured strains are linear combinations areal shear strains. We...
Abstract The Plate Boundary Observatory (PBO), the geodetic component of U.S. National Science Foundation–funded Earthscope program, includes 75 borehole and 6 laser strainmeters ( http://pbo.unavco.org ). are installed at several locations: on Cascadia forearc in Washington state Vancouver Island, Canada; arrays two to nine instruments along North American–Pacific plate boundary California; Mount St. Helens; Yellowstone Park. For deformation signals seconds weeks duration, have a resolution...