A High-Resolution Global Moho Model from Combining Gravimetric and Seismic Data by Using Spectral Combination Methods

The high-resolution Moho depth model is required in various geophysical studies. However, the available models’ resolutions could be improved for this purpose. Large parts of the world still need to be sufficiently covered by seismic data, but existing global Moho models do not fit the present-day requirements for accuracy and resolution. The isostatic models can relatively reproduce a Moho geometry in regions where the crustal structure is in an isostatic equilibrium, but large segments of the tectonic plates are not isostatically compensated, especially along active convergent and divergent tectonic margins. Isostatic models require a relatively good knowledge of the crustal density to correct observed gravity data. To overcome the lack of seismic data and non-uniqueness of gravity inversion, seismic and gravity data should be combined to estimate Moho geometry more accurately. In this study, we investigate the performance of two techniques for combining long- and short-wavelength Moho geometry from seismic and gravity data. Our results demonstrate that both Butterworth and spectral combination techniques can be used to model the Moho geometry. The results show the RMS of Moho depth differences between our model and the reference models are between 1.7 and 4.7 km for the Butterworth filter and between 0.4 and 4.1 km for the spectral combination.

[1]  OUP accepted manuscript , 2022, Geophysical Journal International.

[2]  Chun‐Feng Li,et al.  Geodynamic processes inferred from Moho and Curie depths in Central and Southern African Archean Cratons , 2021 .

[3]  Jonathan C. Evenick.  Glimpses into Earth's history using a revised global sedimentary basin map , 2021 .

[4]  T. Gruber,et al.  The combined global gravity field model XGM2019e , 2020, Journal of Geodesy.

[5]  D. Ravat,et al.  Crustal Composition and Moho Variations of the Central and Eastern United States: Improving Resolution and Geologic Interpretation of EarthScope USArray Seismic Images Using Gravity , 2020, Journal of Geophysical Research: Solid Earth.

[6]  Chuang Xu,et al.  An Approach to Moho Topography Recovery Using the On-Orbit GOCE Gravity Gradients and Its Applications in Tibet , 2019, Remote. Sens..

[7]  H. Zeyen,et al.  Crustal and upper mantle structures of Makran subduction zone, SE Iran by combined surface wave velocity analysis and gravity modeling , 2018, Tectonophysics.

[8]  L. Sjöberg,et al.  Gravity Inversion and Integration: Theory and Applications in Geodesy and Geophysics , 2017 .

[9]  N. Sneeuw,et al.  Generalized model for a Moho inversion from gravity and vertical gravity-gradient data , 2016 .

[10]  Christian Hirt,et al.  Earth2014: 1 arc-min shape, topography, bedrock and ice-sheet models - Available as gridded data and degree-10, 800 spherical harmonics , 2015, Int. J. Appl. Earth Obs. Geoinformation.

[11]  C. Braitenberg,et al.  Moho topography, ranges and folds of Tibet by analysis of global gravity models and GOCE data , 2015, Scientific Reports.

[12]  H. Silvennoinen,et al.  A new Moho boundary map for the northern Fennoscandian Shield based on combined controlled-source seismic and receiver function data , 2014 .

[13]  M. Eshagh,et al.  Combined Moho Estimators , 2014 .

[14]  Wenjin Chen,et al.  Expressions for the Global Gravimetric Moho Modeling in Spectral Domain , 2014, Pure and Applied Geophysics.

[15]  F. Sansò,et al.  Global Moho from the combination of the CRUST2.0 model and GOCE data , 2013 .

[16]  Mikhail K. Kaban,et al.  High resolution regional crustal models from irregularly distributed data: Application to Asia and adjacent areas , 2013 .

[17]  Mohammad Bagherbandi,et al.  Combination of seismic and an isostatic crustal thickness models using Butterworth filter in a spectral approach , 2012 .

[18]  L. Sjöberg,et al.  Non-isostatic effects on crustal thickness: A study using CRUST2.0 in Fennoscandia , 2012 .

[19]  N. K. Pavlis,et al.  The development and evaluation of the Earth Gravitational Model 2008 (EGM2008) , 2012 .

[20]  L. Sjöberg,et al.  A synthetic Earth gravity model based on a topographic-isostatic model , 2012, Studia Geophysica et Geodaetica.

[21]  C. Faccenna,et al.  Mantle conveyor beneath the Tethyan collisional belt , 2011 .

[22]  L. Sjöberg.  Geoid determination by spectral combination of an Earth gravitational model with airborne and terrestrial gravimetry — a theoretical study , 2011 .

[23]  M. Pérez‐Gussinyé,et al.  The role of crustal quartz in controlling Cordilleran deformation , 2011, Nature.

[24]  Lars E. Sjöberg,et al.  A combined global Moho model based on seismic and gravimetric data , 2011 .

[25]  Lars E. Sjöberg,et al.  A method of estimating the Moho density contrast with a tentative application of EGM08 and CRUST2.0 , 2011 .

[26]  Lars E. Sjöberg,et al.  Solving Vening Meinesz-Moritz inverse problem in isostasy , 2009 .

[27]  T. Tiira,et al.  The Moho depth map of the European Plate , 2009 .

[28]  Yong Wang,et al.  Basement structures from satellite-derived gravity field: South China Sea ridge , 2006 .

[29]  Peter Goldstein,et al.  Building and Testing an a priori Geophysical Model for Western Eurasia and North Africa , 2004 .

[30]  S. Sobolev,et al.  Moho topography in the central Andes and its geodynamic implications , 2002 .

[31]  R. Haagmans,et al.  A synthetic Earth for use in geodesy , 2000 .

[32]  C. Bassin,et al.  The Current Limits of resolution for surface wave tomography in North America , 2000 .

[33]  Gabi Laske,et al.  CRUST 5.1: A global crustal model at 5° × 5° , 1998 .

[34]  U. Luosto.  Structure of the Earth's crust in Fennoscandia as revealed from refraction and wide-angle reflection studies , 1997 .

[35]  Z. Martinec.  The Minimum Depth of Compensation of Topographic Masses , 1994 .

[36]  Z. Martinec,et al.  Spherical harmonic expansion of the Earth's crustal thickness up to degree and order 30 , 1991 .

[37]  B. Hager,et al.  Geoid Anomalies in a Dynamic Earth , 1984 .

[38]  L. P. Pellinen.  Physical Geodesy , 1972 .

[39]  F. A. Vening Meinesz,et al.  Une Nouvelle Méthode Pour la Réduction Isostatique Régionale de L’intensité de la Pesanteur , 1931 .

[40]  G. Airy.  II. On the computation of the effect of the attraction of mountain-masses, as disturbing the apparent astronomical latitude of stations in geodetic surveys , 1856, Proceedings of the Royal Society of London.

[41]  J. Pratt.  I. On the attraction of the Himalaya Mountains, and of the elevated regions beyond them, upon the plumb-line in India , 1855, Philosophical Transactions of the Royal Society of London.