Evelyn Price

Interactions between the Landers and Hector Mine, California, Earthquakes from Space Geodesy, Boundary Element Modeling, and Time-Dependent Friction

Bulletin of the Seismological Society of America, May 1, 2002

The M w 7.1 Hector Mine earthquake happened 7 years after the 1992 M w 7.3 Landers earthquake, wi... more

Global topography and bathymetry grid improves research efforts

Eos, Transactions American Geophysical Union, 2004

... Results are provided as eight GMT grid files covering -180° to +180° longitude and -90° to 90... more

Crustal Deformation Associated With the 2002 Denali Fault Earthquake Sequence Observed by SAR Interferometry

AGUFM, Dec 1, 2003

On October 23, 2002, the Mw 6.7 Nenana Mountain earthquake ruptured a 45-kilometer-long segment o... more On October 23, 2002, the Mw 6.7 Nenana Mountain earthquake ruptured a 45-kilometer-long segment of the Denali fault. Eleven days later, November 3, interior Alaska experienced its largest earthquake in recorded history. The Mw 7.9 Denali fault earthquake began 10 kilometers east of the end of the Mw 6.7 rupture and propagated eastward along the Susitna Glacier, Denali, and Totschunda

Coseismic and postseismic deformations associated with the 1992 Landers, California, earthquake measured by synthetic aperture radar interferometry

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Dynamic deformation of Seguam Island, Aleutian Islands, Alaska, 1993-2000: Implications for magmatic and hydrothermal processes

Journal of Geophysical Research, Apr 1, 2004

The most recent volcanic eruption on Seguam Island was detected in December 1992 and lasted until... more The most recent volcanic eruption on Seguam Island was detected in December 1992 and lasted until July or August of 1993. A series of radar interferograms, generated from imagery collected by the European Space Agency's ERS‐1 and ERS‐2 satellites, are used here to map the spatial and temporal evolution of the deformation field from June of 1993 to September of 2000. This evolution consists of a coeruptive period of uplift surrounding the eruption; two posteruptive subsidence signals, centered within each of the two calderas on the island, each of which lasted for 4 years after the end of the eruption; and then uplift beneath the caldera on the eastern side of the island and the surrounding region from mid 1999 through the end of the time series in September 2000. The locations and magnitudes of the sources of the deformation are inferred from the interferometric synthetic aperture radar displacement data using an elastic half‐space Earth model with multiple Mogi point sources and a Levenburg‐Marquardt nonlinear inversion technique. This inference reveals that the sources of subsidence are located within the upper 2 km of the Earth's crust, while the sources of uplift are located below 2.5 km. The locations of dilatational sources are consistent with a model of the volcanic system where ascending magma accumulates below a density or structural boundary near 2.5–3 km depth. The subsidence signals are most likely associated with cooling of shallow magmatic bodies emplaced during the 1992–1993 eruption. However, the possibility that they indicate a combination of magma cooling and depressurization of a hydrothermal system cannot be ruled out using the geodetic data alone. Implications for the long‐term evolution of the volcanic edifice are discussed.

Seismicity and Active Tectonics of Interior Alaska

Deformation of Earth’s continental crust at actively deforming plate boundaries around the world ... more Deformation of Earth’s continental crust at actively deforming plate boundaries around the world is often distributed across a zone whose width can range from hundreds to thousands of kilometers. This is true of the Western United States where major plate boundary strain is concentrated in California and partitioned between the San Andreas Fault (SAF) and the Eastern California Shear Zone (ECSZ). The ECSZ, in particular, has been the region where California’s largest earthquakes of the past 10 years have occurred. The detailed study of the hazardous plate boundary in California has led to many important insights into mechanical interactions among Earth’s deforming crust, its faults on which tectonic stresses are concentrated, and the underlying mantle. Each deforming geologic system, while complex unto itself, can be considered only a single sample within a continuum of how the crust could deform given a range of rheologies, boundary conditions, and applied stresses. We are fortunat...

Accretionary Wedge Mechanics on Venus: A Brittle/Ductile Critical Taper Model

Global topography and bathymetry grid improves research efforts

Eos, Transactions American Geophysical Union, 2004

... Results are provided as eight GMT grid files covering -180° to +180° longitude and -90° to 90... more

Elements of the active magmatic system of Seguam Island, Aleutian Islands, Alaska inferred from co and post-eruptive surface deformation spanning 1993-2000

Seguam Island is located in the central Aleutian Islands at a longitude of 172.5 degrees west. Th... more Seguam Island is located in the central Aleutian Islands at a longitude of 172.5 degrees west. There are two late Quaternary calderas on Seguam, spaced about 8 km apart and located east and west of each other. Each caldera has one Holocene cone inside of it and a third cone lies on the eastern shore of the island. The historically active cone is named Pyre peak, the highest point on the island with an elevation of 1054 meters, and is located within the western caldera (Singer et al., 1992). It has had approximately 9 volcanic episodes since 1786. Holocene volcanism has been basaltic and the most recent eruptive sequence occurred in December of 1992 and July-August of 1993 (Miller et al., 1998). Five radar interferograms, made from SAR imagery archived and downloaded at the Alaska SAR Facility (ASF) from the European Remote Sensing satellite 1 (ERS-1) and 2 (ERS-2) missions, spanning multiple periods of volcanic behavior are presented here. A digital elevation model from the Space Sh...

Small-scale deformations associated with the 1992 Landers, California, earthquake mapped by synthetic aperture radar interferometry phase gradients

Journal of Geophysical Research: Solid Earth, 1998

Abstract. The Landers earthquake ( Mw7.3) occurred on June 28, 1992, and ruptured nearly 100 km o... more Abstract. The Landers earthquake ( Mw7.3) occurred on June 28, 1992, and ruptured nearly 100 km of previously mapped,and unmapped,faults in the Mojave Desert. We use synthetic aperture radar interferometry (InSAR) to examine the cumulative surface deformation between April 24 and August 7, 1992, in a 100 x 100 km region surrounding the northern portion of the earthquake rupture. Also,

Phase gradient approach to stacking interferograms

Journal of Geophysical Research: Solid Earth, 1998

The phase gradient approach is used to construct averages and differences of interferograms witho... more The phase gradient approach is used to construct averages and differences of interferograms without phase unwrapping. Our objectives for change detection are to increase fringe clarity and decrease errors due to tropospheric and ionospheric delay by averaging many interferograms. The standard approach requires phase unwrapping, scaling the phase according to the ratio of the perpendicular baseline, and finally forming the average or difference; however, unique phase unwrapping is usually not possible. Since the phase gradient due to topography is proportional to the perpendicular baseline, phase unwrapping is unnecessary prior to averaging or differencing. Phase unwrapping may be needed to interpret the results, but it is delayed until all of the largest topographic signals are removed. We demonstrate the method by averaging and differencing six interferograms having a suite of perpendicular baselines ranging from 18 to 406 m. Cross‐spectral analysis of the difference between two Ta...

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Dynamic deformation of Seguam Island, Aleutian Islands, Alaska, 1993–2000: Implications for magmatic and hydrothermal processes

Journal of Geophysical Research: Solid Earth, 2004

The most recent volcanic eruption on Seguam Island was detected in December 1992 and lasted until... more The most recent volcanic eruption on Seguam Island was detected in December 1992 and lasted until July or August of 1993. A series of radar interferograms, generated from imagery collected by the European Space Agency's ERS‐1 and ERS‐2 satellites, are used here to map the spatial and temporal evolution of the deformation field from June of 1993 to September of 2000. This evolution consists of a coeruptive period of uplift surrounding the eruption; two posteruptive subsidence signals, centered within each of the two calderas on the island, each of which lasted for 4 years after the end of the eruption; and then uplift beneath the caldera on the eastern side of the island and the surrounding region from mid 1999 through the end of the time series in September 2000. The locations and magnitudes of the sources of the deformation are inferred from the interferometric synthetic aperture radar displacement data using an elastic half‐space Earth model with multiple Mogi point sources an...

Correction [to “Hotspot melting generates both hotspot volcanism and a hotspot swell?” by Jason Phipps Morgan, W. Jason Morgan, and Evelyn Price]

Journal of Geophysical Research, 1996

Hotspot melting generates both hotspot volcanism and a hotspot swell?

Journal of Geophysical Research: Solid Earth, 1995

Two prominent features mark the passage of oceanic lithosphere over a hotspot. The first is the i... more Two prominent features mark the passage of oceanic lithosphere over a hotspot. The first is the initiation of oceanic volcanism leading to a chain of islands or seamounts. The second is the generation of a ∼1‐km‐high, ∼1000‐km‐wide bathymetric swell around the volcanic island chain. Here we show that recent estimates for the volume of hotspot volcanism and the size of the swell suggest a shared origin: swell relief is created by the density reduction created by melting beneath the hotspot. This results in a seafloor age dependence to swell size and volcanism along the Hawaiian chain: beneath younger, thinner lithosphere the hotspot undergoes more decompression melting, resulting in both a larger swell volume and greater island building. For rapidly moving plates the swell root residue from hotspot melting is dragged away from the hotspot by the overriding lithosphere; its buoyancy induces further spreading and thinning of swell root material, producing, for example, the characterist...

Effect of the brittle-ductile transition on the topography of compressive mountain belts on Earth and Venus

Journal of Geophysical Research: Solid Earth, 1994

... Charles A. Williams. Department of Geological and Geophysical Sciences, Princeton University,... more

Interactions between the Landers and Hector Mine, California, Earthquakes from Space Geodesy, Boundary Element Modeling, and Time-Dependent Friction

Bulletin of the Seismological Society of America, 2002

The M w 7.1 Hector Mine earthquake happened 7 years after the 1992 M w 7.3 Landers earthquake, wi... more

The Combined Inversion of Seismic and Geodetic Data for the Source Process of the 16 October 1999 Mw 7.1 Hector Mine, California, Earthquake

Bulletin of the Seismological Society of America, 2002

We investigate the source process of the M w 7.1 Hector Mine earthquake by inverting broadband re... more We investigate the source process of the M w 7.1 Hector Mine earthquake by inverting broadband regional and local seismic displacement waveforms combined with Global Positioning System (GPS) and synthetic aperture radar interferometry (InSAR) geodetic measurements. We find that the three data sets individually produce remarkably similar slip distributions over a multisegment fault. A simultaneous inversion of the three data sets is presented, and the sensitivity of the combined inversion to the weighting of the three independent data sets is examined. The results indicate that the overall length of the fault that slipped is 42 km with a peak slip of 5.50 m and total scalar seismic moment of 6.8 ‫ן‬ 10 19 N m. The majority of slip is located on the western branch of the Lavic Lake fault to the northwest of the hypocenter, although the overall rupture is bilateral with appreciable slip on the Bullion fault to the southeast. Some slip is located on an eastern branch of the Lavic Lake fault, an apparent bifurcation, which is also evident from aftershock locations. The average slip and stress drops are 2.70, 1.62, 1.60 m and 78, 36 and 55 bars for the western Lavic Lake, the eastern Lavic Lake, and Bullion faults, respectively. The results also indicate that the overall rupture process is relatively slow, which is characterized by a several-second delay before the onset of significant slip, a 1.8 km/sec rupture velocity of the primary asperity, and long, spatially variable, dislocation rise times.

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Papers on Geodesy and Gravity Tectonophysics-Subcontinental mantle dynamics: A further analysis based on the joint constraints of dynamic surface topography and free-air gravity (Paper 1999JB900349)

Surface change detection, topographic and geologic mapping of Okmok volcano, Alaska, using high-resolution AIRSAR sensor data

A study of Okmok volcano, located in the Aleutian Islands (Umnak Island -Alaska) was carried out ... more A study of Okmok volcano, located in the Aleutian Islands (Umnak Island -Alaska) was carried out using Airborne Synthetic Aperture Radar (AIRSAR/TOPSAR) radar data acquired in June 2000. It investigated the surface changes that resulted from the 1997 eruption that produced two large lava flows within the caldera. In addition, topographic and geologic mapping was conducted with the aid of AIRSAR data and Landsat satellite imagery. The high-resolution (5-meter) radar backscatter and digital elevation models (DEMs) generated from the SAR dataset were analysed with existing topographic data and its accuracy evaluated. For validation purposes, when compared to previous studies and ground measurements, the AIRSAR data demonstrated excellent spatial and elevation accuracies. This contribution will provide further insights regarding the uses and applications of remotely sensed AIRSAR data for volcanological studies and topographic and geologic mapping purposes.

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Coseismic and postseismic deformations associated with the 1992 Landers, California, earthquake measured by synthetic aperture radar interferometry

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