Is High Topography Around the North Atlantic Supported From the Upper Mantle?

Abstract

AbstractThe traveltime residuals of 393 receiver sites with more than 21,000 P wave and 9,700 S wave arrivals are used to investigate the upper‐mantle P and S wave velocity structure down to the depth of 500 km beneath the regions of high topography of the North Atlantic Caledonian crust. In east Greenland, we observe high‐velocity anomalies beneath high topography. In northern Norway and Sweden, a stable thick lithosphere beneath both the high topography and the Baltic shield exists. Only southern Norway exhibits a weak correlation between high topography and low‐velocity anomalies of P and S waves. Consequently, the correlation of topography versus average relative traveltime residuals in four regions of proposed Cenozoic epeirogenic uplift reveals positive correlation only in southern Norway and negative or absence of correlation in other regions. These results show that high topography does not correlate with the inferred velocity structure of the upper mantle in the North Atlantic realm. Consequently, our findings weaken the hypothesis of dynamic topography and epeirogenic uplift of the Atlantic margins during the Late Cenozoic.