Arctic shallow crustal residual gravity and structure 2019

Derived from public data sources, with 2500m resolution presented in polar stereographic coordinates. Above 64 ⁰N latitude, Arctic Gravity Project data, combined with Sandwell gravity data south of 64⁰N to equatorial latitude 0⁰. Full corrections applied including, but not limited to, Bouguer, Earth curvature and terrain to separate the residual gravity signature of the shallow crust section.

Provided with mapping interpretation of the present day structural configuration revealing the tectonic evolution of the Arctic margins since the Lower Cretaceous onset of oceanic spreading in the Canada Basin.  The interpretation utilizes reduced to pole satellite magnetics, gravity derived Moho modelling, geological mapping of the Arctic, seismic tomographic models, present day seismicity, and mantle residual gravity.

Produced to provide new insight and understanding to regional Arctic geology:

the abrupt termination of Eurasia Basin oceanic spreading along the Laptev rift margin.

the nature and origins of the Chukchi and Lomonosov Ridge crust

the evolution of the oceanic spreading centres to the present day

the potential origin of the Iceland plume



Data sources used in construction of Arctic shallow crustal residual gravity:

Topography:
GEBCO 2014: The GEBCO_2014 Grid, version 20150318, http://www.gebco.net

Gravity:
Sandwell et al gravity: Sandwell, D. T., Müller, R. D., Smith, W. H. F., Garcia, E. and Francis, R., 2014, New global marine gravity model from CryoSat-2 and jason-1 reveals buried tectonic structure. Science, Vol. 346, 6205, pp. 65-67, doi: 10.1126/science.1258213

Arctic Gravity Project : The Arctic Gravity Project (ArcGP) is an international effort dedicated to the compilation of a public-domain gravity grid of the Arctic gravity field north of 64 N. The focus of the gravity grid will be the Arctic Ocean, Greenland, and the continental areas of North America and Russia north of 64 N. This international effort is being led by Rene Forsberg of Denmark and NGA of the USA, who are supported by a Special Working Group composed of members from ten different countries (USA, Canada, Sweden, Finland, England, Norway, Germany, Iceland, Russia, and France). The primary interest of the ArcGP is the compilation of state-of-the-art detailed free-air and bouguer anomaly grids that will be made available to the general public in the year 2000. See also http://earth-info.nga.mil/GandG/wgs84/agp/readme_new.html

Ice:
Bamber, J. 2001. Greenland 5 km DEM, Ice Thickness, and Bedrock Elevation Grids, Version 1. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: https://doi.org/10.5067/01A10Z9BM7KP. [15th December 2018]

Layberry, R. L. and J. Bamber. 2001. A New Ice Thickness and Bed Data Set for the Greenland Ice Sheet: 2. Relationship between Dynamics and Basal Topography, Journal of Geophysical Research. 106. 33,781 - 33,788. https://doi.org/10.1029/2001JD900053

Crust 2.0 ice thickness: Bassin, C., Laske, G. and Masters, G., 2000, The Current Limits of Resolution for Surface Wave Tomography in North America, EOS Trans AGU, 81, F897