3D gravity modelling, isostasy and elastic thickness calculation in the Barent Sea

• Main Authors: Wienecke, Susann, Gernigon, Laurent, Ebbing, Jörg
• Format: Report
• Language: English
• Published: 2008
• Subjects: KONTINENTALSOKKEL; GRAVIMETRI; GEOFYSIKK; Barents Sea
• Online Access: https://hdl.handle.net/11250/2664760

Integrated 3D density and isostatic modelling show that a large difference exist between the Eastern and Western Barents Sea in terms of physical properties in the crust and underlying mantle. To constrain our analysis we make use of a 3D density model based on the velocity model BARENTS50. The density model provides information about the crustal configuration, e.g. the Moho and the loading of the crust including all internal density variation. The calculated gravity anomalies (computed from these density variations) cannot be adjusted to the observed gravity field. Therefore the effect of the Earth's curvature on the gravity calculation was investigated by a coordinate transformation and projection of the 3D model into a spherical 3D model. The error between the modeled and observed gravity remains significantly large. The missing masses, which are needed to minimize the difference, are supposed to be located not only in the crust but also in the mantle. High density material (>3300 kg\/m3) is needed below the Eastern Barents Sea in order to isostatically balance the masses from the thick crust and also to fit the observed gravity field. The isostatically calculated mantle densities correlate well with other results and confirm the large difference between the Eastern and Western Barents Sea.\r. 53898