Geophysical interpretation of features in the marine geoid of fennoscandia

An interpretation of the geoid in and around Scandinavia in terms of crustal depth structure has been made. Correlations as high as 0.92 were found between current models of crustal depth and the geoid for marine areas of Scandinavia. The Fennoscandian land uplift together with its corresponding resultant change of geoid were also found to be highly correlated with crustal depth structure. Results of these correlations compare favorably with theoretical models based upon large scale isostatic behavior of the lithosphere. These models indicate that the crustal thickness variations of Scandinavia are compensated generally at depths greater than 100 km. The results indicate that previous attempts to correlate the geoid with the causes of present land uplift have overestimated the remaining isostatic geoid anomaly in Fennoscandia. The application of these results would reduce the isostatic geoid anomaly by as much as 80% for marine areas of Fennoscandia. This may be interpreted as placing the estimated upper mantle viscosities for Fennoscandia closer to 10²¹ Pa s.