Geologic Provinces Beneath the Greenland Ice Sheet Constrained by Geophysical Data Synthesis

MacGregor, Joseph A.; Colgan, William T.; Paxman, Guy J. G.; Tinto, Kirsty J.; Csathó, Beáta; Darbyshire, Fiona A.; Fahnestock, Mark A.; Kokfelt, Thomas F.; MacKie, Emma J.; Morlighem, Mathieu; Sergienko, Olga V.

doi:10.1029/2023gl107357

Cited by 2 publications

(1 citation statement)

References 105 publications

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“…The changes in ice sheet thickness can not only lead to sea level rise but also greatly affect global climate change [2]. In the literature, the determination of ice thickness has become a prominent focus of scientific investigation [3][4][5].…”

Section: Introductionmentioning

confidence: 99%

Estimation of Antarctic Ice Sheet Thickness Based on 3D Density Interface Inversion Considering Terrain and Undulating Observation Surface Simultaneously

Liu,

Wang,

et al. 2024

Remote Sensing

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The thickness of the Antarctic ice sheet is a crucial parameter for inferring glacier mass and its evolution process. In the literature, the gravity method has been proven to be one of the effective means for estimating ice sheet thickness. And it is a preferred approach when direct measurements are not available. However, few gravity inversion methods are valid in rugged terrain areas with undulating observation surfaces (UOSs). To solve this problem, this paper proposes an improved high-precision 3D density interface inversion method considering terrain and UOSs simultaneously. The proposed method utilizes airborne gravity data at their flight altitudes, instead of the continued data yield from the unstable downward continuation procedure. In addition, based on the undulating right rectangular prism model, the large reliefs of the terrain are included in the iterative inversion. The proposed method is verified on two synthetic examples and is successfully applied to real data in East Antarctica.

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Section: Introductionmentioning

confidence: 99%

Estimation of Antarctic Ice Sheet Thickness Based on 3D Density Interface Inversion Considering Terrain and Undulating Observation Surface Simultaneously

Liu,

Wang,

et al. 2024

Remote Sensing

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Structure of the crust and upper mantle in Greenland and northeastern Canada: insights from anisotropic Rayleigh-wave tomography

Ajourlou,

Darbyshire,

Audet

et al. 2024

Geophysical Journal International

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Summary Seismic velocity models provide important constraints on Greenland’s deep structure, which, in turn, has profound implications for our understanding of the tectonic history of this region. However, the resolution of seismic models has been limited by a sparse network, particularly in northern and central Greenland. We address these limitations by generating new high-resolution Rayleigh-wave phase velocity maps encompassing Greenland and northeastern Canada by processing over three decades of teleseismic earthquake records and incorporating recently added stations in Greenland and Arctic Canada. These phase velocity maps are sensitive to structure from the lower crust down to the sub-lithospheric mantle (25-185 s period). We find significant heterogeneity and a strong correlation between isotropic and anisotropic seismic velocities with inferred geological structure. High seismic velocities associated with cratonic lithosphere are broadly divided into two regions, with a belt of reduced velocity spanning central Greenland, which we interpret as lithospheric erosion resulting from interaction between the Greenland continental keel and the Iceland plume. Within each region, we identify tectonic subdivisions that suggest fundamental differences between the blocks that make up Precambrian Greenland. In the south, the North Atlantic craton (NAC) has a high-velocity keel exhibiting anisotropic stratification. Between the NAC and the cratonic lithosphere further north, the Proterozoic Nagssugtoqidian orogenic belt shows a distinct signature of reduced seismic velocity to ∼75 s period, but then appears to pinch out at depth. The northern Greenland lithosphere exhibits significant isotropic heterogeneity, with a distinct core of high velocities in the northwest (∼55-75 s period) giving way to a set of distinct east-west trending high-velocity belts at longer periods. At all periods sensitive to the lithospheric mantle in this region, anisotropic fast orientations are E-W, consistent with a north-south Precambrian assembly of the Greenland shield. In contrast to the NAC, there is no evidence of anisotropic stratification in the northern part of the cratonic keel. Based on both isotropic and anisotropic phase-velocity anomalies, we suggest that the Phanerozoic Caledonian and Ellesmerian-Franklinian fold belts are relatively thin-skinned features onshore Greenland, though the Caledonian belt may have a stronger signature off the east coast. At the longest periods, a prominent low-velocity anomaly initially centred on Iceland migrates northwards and spreads beneath central-eastern Greenland. Coupled with NW-SE trending anisotropy, this feature is interpreted as the effect of mantle flow radiating outward from the Iceland plume and interacting with the eroded Greenland lithosphere.

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Geologic Provinces Beneath the Greenland Ice Sheet Constrained by Geophysical Data Synthesis

Cited by 2 publications

References 105 publications

Estimation of Antarctic Ice Sheet Thickness Based on 3D Density Interface Inversion Considering Terrain and Undulating Observation Surface Simultaneously

Estimation of Antarctic Ice Sheet Thickness Based on 3D Density Interface Inversion Considering Terrain and Undulating Observation Surface Simultaneously

Structure of the crust and upper mantle in Greenland and northeastern Canada: insights from anisotropic Rayleigh-wave tomography

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