Influence of 3D Earth structure on Glacial Isostatic Adjustment in the
Russian Arctic
Abstract
We validate 1D glacial isostatic adjustment (GIA) models ICE-6G_C
(VM5a) and ICE-7G_NA (VM7), and new 3D GIA models in the Russian Arctic
against a quality-controlled deglacial relative sea-level (RSL)
database. The 1D models correspond to the RSL data along the southern
coast of Barents Sea and Franz-Josef-Land, but show notable misfits with
the White Sea data. We find 3D models fit better than 1D models around
the White Sea while retaining comparable fits in other regions of the
Russian Arctic. Our results reveal (1) RSL in the western Russian Arctic
is sensitive to laterally varying lithosphere and 3D viscosity structure
in the upper mantle; and (2) RSL in the whole Russian Arctic is less
sensitive to 3D viscosity structure in the lower mantle compared to the
upper mantle. The 3D models reveal a compromise in the upper mantle
between background viscosity and scaling factor to best fit the RSL
data.