Abstract
SUMMARY Numerical modelling of postglacial rebound predics a spatially variable pattern of sea-level change. Yet, many previous models predicting Late Pleistocene sea-level change either neglect the load of water added to the oceans, or assume a spatially uniform time-dependent load over the whole ocean. This is a poor approximation of the load near the former ice sheet, since sea-level change varies geographically. In addition, the coastline goemetry changes through time. A spectral technique has been used to solve the sea-level equation on an earth model with axisymmetric distribution of ice and oceans and also for a realistic ice-ocean configuration. The axisymmetric model is useful for demonstrating the fundamental physics involved in sea-level changes caused by changes in surface loads. In particular, it can be seen that the elastic and gravitational response to the load is spread over a great distance, whereas the viscous response is more localized. A realistic ice-ocean configuration has been used to demonstrate that, neglect of the melt-water load underestimates the amount of uplift in Fennoscandia and other regions where rebound occurs in the ocean [as previously noted by Wu & Peltier (1983) in Hudson Bay], and that movement of the coastlines and spatially varying water loads must both be included in calculations for the North Sea and other near field regions with shallow seas. Sea-level calculations including these effects and careful analysis of the sea-level and ice-melting record are required to determine modifications to the viscosity profile and ice model inferred by previous inaccurate models of the ocean load in the near field.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have