Comparative Study of the Uniform and Variable Moho Density Contrast in the Vening Meinesz-Moritz’s Isostatic Scheme for the Gravimetric Moho Recovery

Contribution of satellite altimetry in modelling Moho density contrast in oceanic areas

Journal of Applied Geodesy ◽

10.1515/jag-2018-0034 ◽

2019 ◽

Vol 13 (1) ◽

pp. 33-40 ◽

Cited By ~ 1

Author(s):

M. Abrehdary ◽

L. E. Sjöberg ◽

D. Sampietro

Keyword(s):

Satellite Altimetry ◽

Density Contrast ◽

Contrast Model ◽

Bathymetric Data ◽

Crustal Model ◽

Marine Gravity ◽

Study Results ◽

Vening Meinesz ◽

Satellite Altimetry Data

Abstract The determination of the oceanic Moho (or crust-mantle) density contrast derived from seismic acquisitions suffers from severe lack of data in large parts of the oceans, where have not yet been sufficiently covered by such data. In order to overcome this limitation, gravitational field models obtained by means of satellite altimetry missions can be proficiently exploited, as they provide global uniform information with a sufficient accuracy and resolution for such a task. In this article, we estimate a new Moho density contrast model named MDC2018, using the marine gravity field from satellite altimetry in combination with a seismic-based crustal model and Earth’s topographic/bathymetric data. The solution is based on the theory leading to Vening Meinesz-Moritz’s isostatic model. The study results in a high-accuracy Moho density contrast model with a resolution of 1° × 1° in oceanic areas. The numerical investigations show that the estimated density contrast ranges from 14.2 to 599.7 kg/m3 with a global average of 293 kg/m3. In order to evaluate the accuracy of the MDC2018 model, the result was compared with some published global models, revealing that our altimetric model is able to image rather reliable information in most of the oceanic areas. However, the differences between this model and the published results are most notable along the coastal and polar zones, which are most likely due to that the quality and coverage of the satellite altimetry data are worsened in these regions.

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Decorrelative Mollifier Gravimetry

10.5194/egusphere-egu21-409 ◽

2021 ◽

Author(s):

Willi Freeden

Keyword(s):

Inverse Problems ◽

Density Contrast ◽

Disturbing Potential ◽

Book Series ◽

Inverse Gravimetry ◽

Constructive Approximation ◽

Vening Meinesz ◽

Inverse Gravimetry Problem

<p>The lecture highlights arguments that, coming from multiscale mathematics, have fostered the advancement of gravimetry, as well as those that, generated by gravimetric problems, have contributed to the enhancement in constructive approximation and numerics. Inverse problems in gravimetry are delt with multiscale mollifier decorrelation strategies. Two examples are studied in more detail: (i) Vening Meinesz multiscale surface mollifier regularization to determine locally the Earth's disturbing potential from deflections of vertical, (ii) Newton multiscale volume mollifier regularization of the inverse gravimetry problem to derive locally the density contrast distribution from functionals of the Newton integral and to detect fine particulars of geological relevance. All in all, the Vening Meinesz medal&#160; lecture is meant as an&#160; \lq \lq appetizer'' served to enjoy the tasty meal "Mathematical Geoscience Today'' to be shared by geoscientists and mathematicians in the field of gravimetry. It provides innovative concepts and locally relevant applications presented in a monograph to be published by Birkh&#228;user in the book series &#8220;Geosystems Mathematics&#8221; (2021).</p>

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Comparative analysis of Vening-Meinesz Moritz isostatic models using the constant and variable crust-mantle density contrast – a case study of Zealandia

Journal of Earth System Science ◽

10.1007/s12040-013-0279-x ◽

2013 ◽

Vol 122 (2) ◽

pp. 339-348 ◽

Cited By ~ 4

Author(s):

MOHAMMAD BAGHERBANDI ◽

ROBERT TENZER

Keyword(s):

Comparative Analysis ◽

Density Contrast ◽

Vening Meinesz

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Moho density contrast in Antarctica determined by satellite gravity and seismic models

Geophysical Journal International ◽

10.1093/gji/ggab069 ◽

2021 ◽

Vol 225 (3) ◽

pp. 1952-1962

Author(s):

M Abrehdary ◽

L E Sjöberg

Keyword(s):

Thick Layer ◽

Density Contrast ◽

Mountain Range ◽

Satellite Gravity ◽

Crust And Upper Mantle ◽

Spectral Window ◽

Isostatic Adjustment ◽

Vening Meinesz ◽

Almost All ◽

Seismic Models

SUMMARY As recovering the crust–mantle/Moho density contrast (MDC) significantly depends on the properties of the Earth's crust and upper mantle, varying from place to place, it is an oversimplification to define a constant standard value for it. It is especially challenging in Antarctica, where almost all the bedrock is covered with a thick layer of ice, and seismic data cannot provide a sufficient spatial resolution for geological and geophysical applications. As an alternative, we determine the MDC in Antarctica and its surrounding seas with a resolution of 1° × 1° by the Vening Meinesz-Moritz gravimetric-isostatic technique using the XGM2019e Earth Gravitational Model and Earth2014 topographic/bathymetric information along with CRUST1.0 and CRUST19 seismic crustal models. The numerical results show that our model, named HVMDC20, varies from 81 kg m−3 in the Pacific Antarctic mid-oceanic ridge to 579 kg m−3 in the Gamburtsev Mountain Range in the central continent with a general average of 403 kg m−3. To assess our computations, we compare our estimates with those of some other gravimetric as well as seismic models (KTH11, GEMMA12C, KTH15C and CRUST1.0), illustrating that our estimates agree fairly well with KTH15C and CRUST1.0 but rather poor with the other models. In addition, we compare the geological signatures with HVMDC20, showing how the main geological structures contribute to the MDC. Finally, we study the remaining glacial isostatic adjustment effect on gravity to figure out how much it affects the MDC recovery, yielding a correlation of the optimum spectral window (7≤ n ≤12) between XGM2019e and W12a GIA models of the order of ∼0.6 contributing within a negligible $ \pm 14$ kg m−3 to the MDC.

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Towards the Moho depth and Moho density contrast along with their uncertainties from seismic and satellite gravity observations

Journal of Applied Geodesy ◽

10.1515/jag-2017-0019 ◽

2017 ◽

Vol 11 (4) ◽

Cited By ~ 1

Author(s):

M. Abrehdary ◽

L.E. Sjöberg ◽

M. Bagherbandi ◽

D. Sampietro

Keyword(s):

Inverse Problem ◽

Density Contrast ◽

Moho Depth ◽

Standard Errors ◽

Combined Method ◽

Satellite Gravity ◽

Global Models ◽

Moho Depths ◽

Vening Meinesz ◽

Models Of Gravity

AbstractWe present a combined method for estimating a new global Moho model named KTH15C, containing Moho depth and Moho density contrast (or shortly Moho parameters), from a combination of global models of gravity (GOCO05S), topography (DTM2006) and seismic information (CRUST1.0 and MDN07) to a resolution of 1° × 1° based on a solution of Vening Meinesz-Moritz’ inverse problem of isostasy. This paper also aims modelling of the observation standard errors propagated from the Vening Meinesz-Moritz and CRUST1.0 models in estimating the uncertainty of the final Moho model. The numerical results yield Moho depths ranging from 6.5 to 70.3 km, and the estimated Moho density contrasts ranging from 21 to 650 kg/m

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Recovering Moho constituents from satellite altimetry and gravimetric data for Europe and surroundings

Journal of Applied Geodesy ◽

10.1515/jag-2019-0011 ◽

2019 ◽

Vol 13 (4) ◽

pp. 291-303 ◽

Cited By ~ 2

Author(s):

M. Abrehdary ◽

L. E. Sjöberg

Keyword(s):

Satellite Altimetry ◽

Numerical Results ◽

Density Contrast ◽

Moho Depth ◽

Topographic Data ◽

Gulf Of Bothnia ◽

Gravimetric Data ◽

Moho Depths ◽

Vening Meinesz ◽

Total Average

Abstract In this research, we present a local Moho model, named MOHV19, including Moho depth and Moho density contrast (or shortly Moho constituents) with corresponding uncertainties, which are mapped from altimetric and gravimetric data (DSNSC08) in addition to seismic tomographic (CRUST1.0) and Earth topographic data (Earth2014) to a resolution of 1° × 1° based on a solution of Vening Meinesz-Moritz’ theory of isostasy. The MOHV19 model covers the area of entire European plate along with the surrounding oceans, bounded by latitudes (30 °N–82 °N) and longitudes (40 °W–70 °E). The article aims to interpret the Moho model resulted via altimetric and gravimetric information from the geological and geophysical perspectives along with investigating the relation between the Moho depth and Moho density contrast. Our numerical results show that estimated Moho depths range from 7.5 to 57.9 km with continental and oceanic averages of 41.3 ± 4.9 km and 21.6 ± 9.2 km, respectively, and an overall average of 30.9 ± 12.3 km. The estimated Moho density contrast ranges from 60.2 to 565.8 kg/m3, with averages of 421.8 ± 57.9 and 284.4 ± 62.9 kg/m3 for continental and oceanic regions, respectively, with a total average of 350.3 ± 91.5 kg/m3. In most areas, estimated uncertainties in the Moho constituents are less than 3 km and 40 kg/m3, respectively, but they reach to much more significant values under Iceland, parts of Gulf of Bothnia and along the Kvitoya Island. Comparing the Moho depths estimated by MOHV19 and those derived by CRUST1.0, MDN07, GRAD09 and MD19 models shows that MOHV19 agree fairly well with CRUST1.0 but rather poor with other models. The RMS difference between the Moho density contrasts estimated by MOHV19 and CRUST1.0 models is 49.45 kg/m3.

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