Antarctic crustal modeling from the spectral correlation of free‐air gravity anomalies with the terrain

Frese, Ralph R. B. von; Tan, Li; Kim, Jeong Woo; Bentley, Charles R.

doi:10.1029/1999jb900232

Cited by 54 publications

(60 citation statements)

References 28 publications

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“…In summary, the GOCE sensor system is a very sophisticated gravitational laboratory in space, containing several novelties. Some of its sensors are similar to those intended to be used for future fundamental physics missions such as LISA (Laser Interferometry Space Antenna) (Vitale 2009), LISA-Pathfinder (Armano et al 2009), STEP (Sumner 2009), or Microscope (Touboul 2009). …”

Section: Goce Gravitational Sensor Systemmentioning

confidence: 99%

GOCE, Satellite Gravimetry and Antarctic Mass Transports

Rummel

Horwath

et al. 2011

Surv Geophys

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In 2009 the European Space Agency satellite mission GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) was launched. Its objectives are the precise and detailed determination of the Earth's gravity field and geoid. Its core instrument, a three axis gravitational gradiometer, measures the gravity gradient components V xx , V yy , V zz and V xz (second-order derivatives of the gravity potential V) with high precision and V xy , V yz with low precision, all in the instrument reference frame. The long wavelength gravity field is recovered from the orbit, measured by GPS (Global Positioning System). Characteristic elements of the mission are precise star tracking, a Sun-synchronous and very low (260 km) orbit, angular control by magnetic torquing and an extremely stiff and thermally stable instrument environment. GOCE is complementary to GRACE (Gravity Recovery and Climate Experiment), another satellite gravity mission, launched in 2002. While GRACE is designed to measure temporal gravity variations, albeit with limited spatial resolution, GOCE is aiming at maximum spatial resolution, at the expense of accuracy at large spatial scales. Thus, GOCE will not provide temporal variations but is tailored to the recovery of the fine scales of the stationary field. GRACE is very successful in delivering time series of large-scale mass changes of the Antarctic ice sheet, among other things. Currently, emphasis of respective GRACE analyses is on regional refinement and on changes of temporal trends. One of the challenges is the separation of ice mass changes from glacial isostatic adjustment. Already from a few months of GOCE data, detailed gravity gradients can be recovered. They are presented here for the area of Antarctica. As one application, GOCE gravity gradients are an important addition to the sparse gravity data of Antarctica. They will help studies of the crustal and lithospheric field. A second area of application is ocean circulation. The geoid surface from the gravity field model GOCO01S allows us now to generate rather detailed maps of the mean dynamic ocean topography and of geostrophic flow velocities in the region of the Antarctic Circumpolar Current.

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Section: Goce Gravitational Sensor Systemmentioning

confidence: 99%

GOCE, Satellite Gravimetry and Antarctic Mass Transports

Rummel

Horwath

et al. 2011

Surv Geophys

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“…Using this formula in our context, instead of a more sophisticated method (as used in [2]) leads to a maximum error of 5%. The terrain gravity e¡ect, due to the mass distribution around and beneath the surface, is then computed in a manner that simulates the CHAMP altitude e¡ect, e¡ectively a low-pass ¢lter.…”

Section: Methodsmentioning

confidence: 99%

“…It is based on a compilation of all the available data [1] to derive a gravitational potential up to degree 120. This solution has already served as the basis for a global study over Antarctica [2]. Unfortunately this gravity database is not homogeneous, either in terms of quality or in terms of data distribution.…”

Section: Introductionmentioning

confidence: 99%

Crustal thickness in Antarctica from CHAMP gravimetry

Llubes

Florsch²,

Legrésy

et al. 2003

Earth and Planetary Science Letters

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CHAMP, flying at an altitude of about 400 km, is the first of a new generation of satellites dedicated to Earth gravity field observation. The high-quality data have generated new gravity field models: EIGEN-1S in 2001, and EIGEN-2S more recently. The gravitational potential is decomposed into spherical harmonic coefficients and in this study we use the free air gravity anomalies reconstituted up to degree 60, at zero altitude. The anomalies for the Antarctic continent range from 357 to 65 mGal. We have modeled the gravity effect from the ice, the ocean and the bedrock, using a 666 km cut-off filter to simulate the resolution obtained by CHAMP. Computing the differences between this terrain effect and the CHAMP map provides a map of the Bouguer anomalies. Because of the dominant influence of the crust, we first used a crustal thickness model from seismology. This gives a map of the mantle Bouguer anomalies, the range of which is still large (between 3255 and 216 mGal) indicating imperfections in the crust model. By appealing to isostasy we then imposed the condition that this mantle Bouguer anomaly should vanish and therefore solve for a new resulting crustal thickness. This gravity-based crust model gives thicknesses from 8.5 to 42.6 km in the zone of interest. There is a good general agreement with seismological models, but our models shows more detail, particularly in the western part of the continent. These details are in agreement with geological studies. ß

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“…The veracity of this new approach was tested at satellite altitude (=150 km) on terrain and gravity data of the Antarctic (von Frese et al, 1999) and East Asia (Tan and von Frese, 1997;Tan, 1998) assuming the Airy-Heiskanen hypothesis. We obtained Moho estimates for these regions that compare very favorably with determinations from large-offset seismic studies, being on average well within 10% of the seismic determinations.…”

Section: Introductionmentioning

confidence: 99%

Crustal modeling from spectrally correlated free‐air and terrain gravity data—A case study of Ohio

2000

Self Cite

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We investigate the use of spectral correlation theory to analyze terrain gravity effects and free-air gravity anomalies of Ohio for possible constraints on the thickness variations and neotectonics of the crust. Terrain gravity effects are computed from the topography by Gauss-Legendre quadrature integration and are compared against independent free-air gravity anomaly observations for their wavenumber correlation spectrum. Spectral correlation filters are designed accordingly to extract terrain-correlated free-air gravity anomalies that are subtracted from the terrain gravity effects for estimates of the compensated terrain gravity effects. These effects are used to model the Moho by inversion, assuming they predominantly reflect crustal thickness variations. Our results characterize the middle third of Ohio as a broad zone of thickened Precambrian crust, which also may include rifted regions where the thickness of the prerift crust has been reduced greatly. Furthermore, we find that about 83% of the instrumentally determined earthquake epicenters are located within the inferred thinner regions of Ohio's crust or at their margins where compressional stresses may dominate. In general, these crustal thickness variations provide new constraints on modeling the tectonic evolution and geotechnical parameters of the crust-constraints that are important for evaluating earthquake hazards, the distribution and extraction of crustal resources, and the storage of hazardous waste and other crustal engineering applications.

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Antarctic crustal modeling from the spectral correlation of free‐air gravity anomalies with the terrain

Cited by 54 publications

References 28 publications

GOCE, Satellite Gravimetry and Antarctic Mass Transports

GOCE, Satellite Gravimetry and Antarctic Mass Transports

Crustal thickness in Antarctica from CHAMP gravimetry

Crustal modeling from spectrally correlated free‐air and terrain gravity data—A case study of Ohio

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