Can tectonic processes be recovered from new gravity satellite data?

Михайлов, В. О.; Tikhotsky, S. A.; Diament, M.; Panet, I.; Ballu, Valérie

doi:10.1016/j.epsl.2004.09.035

Cited by 38 publications

(21 citation statements)

References 22 publications

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“…Gravity fields mapped by GRACE can reveal details at a resolution of about 400 km, but the relatively large observational errors at finer resolution demand large sources with sufficiently large spatial dimensions. Future observations might include detection of postglacial readjustment of Earth's ductile mantle (14) at continent-wide scales, strain accumulation at megathrust zones (15), and postseismic relaxation of the mantle after a Sumatra-sized earthquake, as has already been detected by GPS (16). These processes affect volumes of material extending to several hundreds of kilometers in depth, and highresolution global gravity measurements should provide good and unique constraints on the depth-dependent nature of the associated mantle flow fields.…”

Section: A New Class Of Earthquake Observationsmentioning

confidence: 86%

A New Class of Earthquake Observations

Pollitz

2006

Science

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Section: A New Class Of Earthquake Observationsmentioning

confidence: 86%

A New Class of Earthquake Observations

Pollitz

2006

Science

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“…Co‐seismic gravitational perturbations are visible from gravity space mission data [ Mikhailov et al , 2004; Sabadini et al , 2005; Han et al , 2006; de Linage et al , 2009]. We herein analyze co‐seismic geoid and gravity anomalies from the 2004 Sumatran earthquake by means of a new, compressible self‐gravitating Earth model, that is fully realistic as it builds on PREM [ Dziewonski and Anderson , 1981] and represents the elastic limit of viscoelastic models, recently used for post‐glacial rebound studies [ Cambiotti et al , 2010] and developed for co‐seismic studies by Smylie and Mansinha [1971] and Sun and Okubo [1993].…”

Section: Introductionmentioning

confidence: 99%

GRACE gravity data help constraining seismic models of the 2004 Sumatran earthquake

et al. 2011

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The analysis of Gravity Recovery and Climate Experiment (GRACE) Level 2 data time series from the Center for Space Research (CSR) and GeoForschungsZentrum (GFZ) allows us to extract a new estimate of the co‐seismic gravity signal due to the 2004 Sumatran earthquake. Owing to compressible self‐gravitating Earth models, including sea level feedback in a new self‐consistent way and designed to compute gravitational perturbations due to volume changes separately, we are able to prove that the asymmetry in the co‐seismic gravity pattern, in which the north–eastern negative anomaly is twice as large as the south–western positive anomaly, is not due to the previously overestimated dilatation in the crust. The overestimate was due to a large dilatation localized at the fault discontinuity, the gravitational effect of which is compensated by an opposite contribution from topography due to the uplifted crust. After this localized dilatation is removed, we instead predict compression in the footwall and dilatation in the hanging wall. The overall anomaly is then mainly due to the additional gravitational effects of the ocean after water is displaced away from the uplifted crust, as first indicated by de Linage et al. (2009). We also detail the differences between compressible and incompressible material properties. By focusing on the most robust estimates from GRACE data, consisting of the peak‐to‐peak gravity anomaly and an asymmetry coefficient, that is given by the ratio of the negative gravity anomaly over the positive anomaly, we show that they are quite sensitive to seismic source depths and dip angles. This allows us to exploit space gravity data for the first time to help constraining centroid‐momentum‐tensor (CMT) source analyses of the 2004 Sumatran earthquake and to conclude that the seismic moment has been released mainly in the lower crust rather than the lithospheric mantle. Thus, GRACE data and CMT source analyses, as well as geodetic slip distributions aided by GPS, complement each other for a robust inference of the seismic source of large earthquakes. Particular care is devoted to the spatial filtering of the gravity anomalies estimated both from observations and models to make their comparison significant.

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“…The most devastating earthquakes of the modern epoch have all occurred at subduction zones, causing extensive damage in densely populated areas. In these highly seismically active regions, satellite gravity data are extremely valuable for constraining the rupture mechanism and quantifying post-seismic deformation, because they ''view'' undersea epicentral areas that can hardly be surveyed by ground geodetic and geophysical techniques (Mikhailov et al 2004;Han et al 2006). By monitoring the seismic cycle and slow aseismic motions, satellite gravity can contribute to a better understanding of the mechanisms of stress accumulation and stress release.…”

Section: Measuring and Modeling The Glacial Isostatic Adjustment Larmentioning

confidence: 99%

“…Concerning solid Earth signals, a study of geoid variations at GRACE resolution associated with earthquakes of varying magnitude can be found in de Viron et al (2008), while Mikhailov et al (2004) showed that a mission 10 times more precise than GRACE would allow for the detection of the accumulation of mass along active tectonic zones, discrimination of fault plane models, and the monitoring of asperities on locked seismic zones. Finally, the geoid change due to GIA in the Hudson Bay area is in the order of 1-2 mm/year on the geoid (Barletta and Bordoni 2009); however, distinguishing GIA signals associated with different viscosity profiles within the Earth requires a significantly higher accuracy (Wahr and Davis 2002;Vermeersen 2005).…”

Section: Summary Of Emotion Science Requirementsmentioning

confidence: 99%

Earth System Mass Transport Mission (e.motion): A Concept for Future Earth Gravity Field Measurements from Space

et al. 2012

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In the last decade, satellite gravimetry has been revealed as a pioneering technique for mapping mass redistributions within the Earth system. This fact has allowed us to have an improved understanding of the dynamic processes that take place within and -012-9209-8 between the Earth's various constituents. Results from the Gravity Recovery And Climate Experiment (GRACE) mission have revolutionized Earth system research and have established the necessity for future satellite gravity missions. In 2010, a comprehensive team of European and Canadian scientists and industrial partners proposed the e.motion (Earth system mass transport mission) concept to the European Space Agency. The proposal is based on two tandem satellites in a pendulum orbit configuration at an altitude of about 370 km, carrying a laser interferometer inter-satellite ranging instrument and improved accelerometers. In this paper, we review and discuss a wide range of mass signals related to the global water cycle and to solid Earth deformations that were outlined in the e.motion proposal. The technological and mission challenges that need to be addressed in order to detect these signals are emphasized within the context of the scientific return. This analysis presents a broad perspective on the value and need for future satellite gravimetry missions.

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Can tectonic processes be recovered from new gravity satellite data?

Cited by 38 publications

References 22 publications

A New Class of Earthquake Observations

A New Class of Earthquake Observations

GRACE gravity data help constraining seismic models of the 2004 Sumatran earthquake

Earth System Mass Transport Mission (e.motion): A Concept for Future Earth Gravity Field Measurements from Space

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