| Summary: | Strong compressive and shear stresses generated by glacial loading and unloading have a direct impact on near-surface geological processes. Glacial stresses are constantly evolving, creating stress perturbations in the lithosphere that extend significant distances away from the ice load. In the Arctic, periodic methane seepage and faulting have been recurrently associated with glacial cycles. However, the evolution of the Arctic glacial stress field and its impact on the upper lithosphere have not been investigated. Here, we compute the evolution in space and time of the glacial stresses induced in the Arctic lithosphere by the North American, Eurasian and Greenland ice sheets during the latest glaciation. We use glacial isostatic adjustment (GIA) methodology to investigate the response of spherical, viscoelastic Earth models with varying lithospheric thickness to the ice loads. The magnitude of the vertical GIA-related stress closely follows the changing ice thickness, whilst the horizontal stresses are governed by the flexural response. We find that the GIA-induced maximum horizontal stress (σH) is compressive in regions characterized by thick ice cover, with magnitudes of 20-25 MPa in Fennoscandia and 35-40 MPa in Greenland at the last glacial maximum. Simultaneously, a tensile regime with σH magnitude down to -16 MPa dominates across far-field regions (in the forebulges) with a mean of -4 MPa across the Fram Strait. At present time, induced compressional stresses have decreased by a factor 4 across formerly glaciated regions and in the Fram Strait, σH remains tensile with an East-West orientation. The association of relatively high shear stress (~3-5 MPa) and tensile horizontal stresses along off the west-Svalbard coast could be sufficient to promote fault reactivation and dilation that favor gas leakage from gas reservoirs. This file contains data from the TE60, TE120 and VL20-175 models exported at 23 kyrs BP (LGM) and present time, sampled at 2.5 km depth.
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