The spherical terrain correction and its effect on the gravimetric-isostatic Moho determination
2016 (English)In: Geophysical Journal International, ISSN 0956-540X, E-ISSN 1365-246X, Vol. 204, no 1, 262-273 p.Article in journal (Refereed) PublishedText
In this study, the Moho depth is estimated based on the refined spherical Bouguer gravity disturbance and DTM2006 topographic data using the Vening Meinesz-Moritz gravimetric-isostatic hypothesis. In this context, we compute the refined spherical Bouguer gravity disturbances in a set of 1 degrees x 1 degrees blocks. The spherical terrain correction, a residual correction to each Bouguer shell, is computed using rock heights and ice sheet thicknesses from the DTM2006 and Earth2014 models. The study illustrates that the defined simple Bouguer gravity disturbance corrected for the density variations of the oceans, ice sheets and sediment basins and also the non-isostatic effects needs a significant terrain correction to become the refined Bouguer gravity disturbance, and that the isostatic gravity disturbance is significantly better defined by the latter disturbance plus a compensation attraction. Our study shows that despite the fact that the lateral variation of the crustal depth is rather smooth, the terrain affects the result most significantly in many areas. The global numerical results show that the estimated Moho depths by the simple and refined spherical Bouguer gravity disturbances and the seismic CRUST1.0 model agree to 5.6 and 2.7 km in RMS, respectively. Also, the mean value differences are 1.7 and 0.2 km, respectively. Two regional numerical studies show that the RMS differences between the Moho depths estimated based on the simple and refined spherical Bouguer gravity disturbance and that using CRUST1.0 model yield fits of 4.9 and 3.2 km in South America and yield 3.2 and 3.4 km in Fennoscandia, respectively.
Place, publisher, year, edition, pages
Oxford University Press, 2016. Vol. 204, no 1, 262-273 p.
Satellite gravity, Gravity anomalies and Earth structure, Mantle processes, Mid-ocean ridge processes, Rheology: crust and lithosphere, Rheology: mantle
IdentifiersURN: urn:nbn:se:kth:diva-182164DOI: 10.1093/gji/ggv450ISI: 000368427000016ScopusID: 2-s2.0-84958610069OAI: oai:DiVA.org:kth-182164DiVA: diva2:904111
QC 201602182016-02-182016-02-162016-03-17Bibliographically approved