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Vanshan Wright

Bio: Vanshan Wright is an academic researcher from Woods Hole Oceanographic Institution. The author has contributed to research in topics: Seismometer & Drainage basin. The author has an hindex of 4, co-authored 10 publications receiving 36 citations. Previous affiliations of Vanshan Wright include University of California, San Diego & Southern Methodist University.

Papers
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Journal ArticleDOI
TL;DR: The InSight lander measured the seismic velocity of the Martian crust and used a rock physics model to interpret those velocities and constrain hydrogeological properties.
Abstract: The seismometer deployed by the InSight lander measured the seismic velocity of the Martian crust. We use a rock physics model to interpret those velocities and constrain hydrogeological properties. The seismic velocity of the upper ~10 km is too low to be ice-saturated. Hence there is no cryosphere that confines deeper aquifers. An increase in seismic velocity at depths of ~10 km could be explained by a few volume percent of mineral cement (1-5%) in the pores and may document the past or present depth of aquifers.

24 citations

Journal ArticleDOI
TL;DR: Park et al. as mentioned in this paper proposed a method to solve the problem of global climate change by using geoscience and mineral resources from the Korea Institute of GeoScience and Mineral Resources (KIMG).
Abstract: Junghyun Park,1 Il-Young Che,2 Brian Stump,1 Chris Hayward,1 Fransiska Dannemann,1,* SeongJu Jeong,1 Kevin Kwong,1 Sarah McComas,1 Harrison R. Oldham,1 Monique M. Scales1,† and Vanshan Wright1 1Roy Huffington Department of Earth Sciences, Southern Methodist University, P.O. Box 750395 Dallas, TX 75275-0395, USA. E-mail: junghyunp@smu.edu 2Korea Institute of Geoscience and Mineral Resources, 124 Gwahak-ro Yuseong-gu, Daejeon 34132, Korea

14 citations

Journal ArticleDOI
TL;DR: In this article, the authors use CHIRP seismic data, satellite imagery, and regional meteorological data to quantify and assess controls on the recent lake level rises, and propose that the lakes experience intermittent periods of hydraulic connectivity along reactivated or newly developed stratigraphic-controlled sub-surface transport pathways.
Abstract: Lakes Enriquillo and Azuei, the two largest lakes in Hispaniola and in the Caribbean, have risen 10 and 5 m respectively within the last 8 years. Higher lake levels have submerged towns, road systems, agricultural lands and utilities, and have threatened to submerge the major overland highway that connects the Dominican Republic and Haiti. In this study, we use CHIRP seismic data, satellite imagery, and regional meteorological data to quantify and assess controls on the recent lake level rises. Although data are limited, the analyses indicate that the lakes’ water level changes may be attributed to a combination of increased rainfall and natural or man-made changes to the hydraulic connectivity of the various water bodies within the drainage basin. We show that a weak correlation exists between changes in Lake Enriquillo’s and Azuei’s water levels and precipitation rates (0.2 and 0.08 respectively, 1984-2012) and that both lakes experience periods of anti-correlation where, for example, water level drops at Lake Azuei (~20 masl) coincide with water level rises at Lake Enriquillo (41 mbsl). From these observations, we propose that the lakes experience intermittent periods of hydraulic connectivity along reactivated or newly developed stratigraphic-controlled sub-surface transport pathways. We also note that moderately small earthquakes along the large active fault system that extends through both lakes may promote or limit hydraulic conductivity on decadal or shorter time scales. The extents to which recent earthquakes have triggered changes in groundwater flow at this site remain unclear but represent an important topic of future research.

10 citations

Journal ArticleDOI
TL;DR: In this article, the authors collected and analyzed seismic and shallow sediment core data in and around Kingston Harbor and revealed a previously unrecognized strike-slip fault system that accommodates strain via a complex mix of compression and extension.
Abstract: Tectonics in Southeast Jamaica is poorly understood, but the region may contain currently unknown faults that could generate large‐magnitude earthquakes. This study constrains tectonics in Southeast Jamaica by collecting and analyzing seismic and shallow sediment core data in and around Kingston Harbor. Seismic results reveal a previously unrecognized strike‐slip fault system that accommodates strain via a complex mix of compression and extension. The faults appear to be a blind extension of one major fault (i.e., The Bull Bay Strike‐Slip Fault) within the Enriquillo‐Plantain Garden Fault Zone. This fault system may represent significant hazards to Kingston Jamaica because the fault is active, located less than 5 km from the city, and a complete rupture of the fault could generate aMw 5.8–6.9 earthquake. Our analyses highlight the need for continued paleoseismic studies, both onshore and offshore Jamaica.

5 citations


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01 Jan 1996
TL;DR: In this paper, the amount of water outgassed from Mars by impact erosion and hydrodynamic escape is estimated to be between 6 to 160 m. The two sets of estimates may be reconciled if early in its history, Mars lost part of its atmosphere.
Abstract: Estimates of the amount of water outgassed from Mars, based on the composition of the atmosphere, range from 6 to 160 m, as compared with 3 km for the Earth. In contrast, large flood features, valley networks, and several indicators of ground ice suggest that at least 500 m of water have outgassed. The two sets of estimates may be reconciled if early in its history, Mars lost part of its atmosphere by impact erosion and hydrodynamic escape.

910 citations

12 Dec 2019
Abstract: The InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) mission landed in Elysium Planitia on Mars on 26 November 2018 and fully deployed its seismometer by the end of February 2019. The mission aims to detect, characterize and locate seismic activity on Mars, and to further constrain the internal structure, composition and dynamics of the planet. Here, we present seismometer data recorded until 30 September 2019, which reveal that Mars is seismically active. We identify 174 marsquakes, comprising two distinct populations: 150 small-magnitude, high-frequency events with waves propagating at crustal depths and 24 low-frequency, subcrustal events of magnitude M w 3–4 with waves propagating at various depths in the mantle. These marsquakes have spectral characteristics similar to the seismicity observed on the Earth and Moon. We determine that two of the largest detected marsquakes were located near the Cerberus Fossae fracture system. From the recorded seismicity, we constrain attenuation in the crust and mantle, and find indications of a potential low-S-wave-velocity layer in the upper mantle. Mars is seismically active: 24 subcrustal magnitude 3–4 marsquakes and 150 smaller events have been identified up to 30 September 2019, by an analysis of seismometer data from the InSight lander.

70 citations

Journal ArticleDOI
28 Oct 2022-Science
TL;DR: Yang et al. as discussed by the authors detected surface waves from two meteorite impacts on Mars and measured group velocity dispersion along the impact-lander path, obtaining a direct constraint on crustal structure away from the InSight lander.
Abstract: We detected surface waves from two meteorite impacts on Mars. By measuring group velocity dispersion along the impact-lander path, we obtained a direct constraint on crustal structure away from the InSight lander. The crust north of the equatorial dichotomy had a shear wave velocity of approximately 3.2 kilometers per second in the 5- to 30-kilometer depth range, with little depth variation. This implies a higher crustal density than inferred beneath the lander, suggesting either compositional differences or reduced porosity in the volcanic areas traversed by the surface waves. The lower velocities and the crustal layering observed beneath the landing site down to a 10-kilometer depth are not a global feature. Structural variations revealed by surface waves hold implications for models of the formation and thickness of the martian crust. Description An insightful impact On 24 December 2021, the seismometer for the InSight mission on Mars detected a large seismic event with a distinct signature. Posiolova et al. discovered that the event was caused by a meteor impact on the surface of Mars, which was confirmed by satellite observations of a newly formed 150-kilometer crater. The surface nature and size of the impact allowed Kim et al. to detect surface waves from the event, which have yet to be observed on Mars. These surface waves help to untangle the structure of the Martian crust, which has various amounts of volcanic and sedimentary rock, along with subsurface ice, in different regions of the planet (see the Perspective by Yang and Chen). The characteristics of the impact itself are important because they provide a seismic fingerprint of an impact event that is different from the marsquakes observed so far. —BG A new crater formed on the surface of Mars was detected with the seismometer on the InSight mission.

36 citations

Journal ArticleDOI
Abstract: . On 3 September 2017 official channels of the Democratic People's Republic of Korea announced the successful test of a thermonuclear device. Only seconds to minutes after the alleged nuclear explosion at the Punggye-ri nuclear test site in the mountainous region in the country's northeast at 03:30:02 (UTC), hundreds of seismic stations distributed all around the globe picked up strong and distinct signals associated with an explosion. Different seismological agencies reported body wave magnitudes of well above 6.0, consequently estimating the explosive yield of the device on the order of hundreds of kT TNT equivalent. The 2017 event can therefore be assessed as being multiple times larger in energy than the two preceding North Korean events in January and September 2016. This study provides a multi-technology analysis of the 2017 North Korean event and its aftermath using a wide array of geophysical methods. Seismological investigations locate the event within the test site at a depth of approximately 0.6 km below the surface. The radiation and generation of P- and S-wave energy in the source region are significantly influenced by the topography of the Mt. Mantap massif. Inversions for the full moment tensor of the main event reveal a dominant isotropic component accompanied by significant amounts of double couple and compensated linear vector dipole terms, confirming the explosive character of the event. The analysis of the source mechanism of an aftershock that occurred around 8 min after the test in the direct vicinity suggest a cavity collapse. Measurements at seismic stations of the International Monitoring System result in a body wave magnitude of 6.2, which translates to an yield estimate of around 400 kT TNT equivalent. The explosive yield is possibly overestimated, since topography and depth phases both tend to enhance the peak amplitudes of teleseismic P waves. Interferometric synthetic aperture radar analysis using data from the ALOS-2 satellite reveal strong surface deformations in the epicenter region. Additional multispectral optical data from the Pleiades satellite show clear landslide activity at the test site. The strong surface deformations generated large acoustic pressure peaks, which were observed as infrasound signals with distinctive waveforms even at distances of 401 km. In the aftermath of the 2017 event, atmospheric traces of the fission product 133Xe were detected at various locations in the wider region. While for 133Xe measurements in September 2017, the Punggye-ri test site is disfavored as a source by means of atmospheric transport modeling, detections in October 2017 at the International Monitoring System station RN58 in Russia indicate a potential delayed leakage of 133Xe at the test site from the 2017 North Korean nuclear test.

34 citations