K. Lambeck et al., TESTS OF GLACIAL REBOUND MODELS FOR FENNOSCANDINAVIA BASED ON INSTRUMENTED SEA-LEVEL AND LAKE-LEVEL RECORDS, Geophysical journal international, 135(2), 1998, pp. 375-387
Evidence for changing sea levels in northwestern Europe related to gla
cial rebound is found in both the geological record of the past millen
nia and in the instrumental records of the past two centuries. The lat
ter records are of two types: records of sealevel change, primarily fr
om the Baltic and the Gulfs of Finland and Bothnia, and records of the
tilting of some of the larger lakes in both Finland and Sweden. The s
ealevel records are particularly important because of their long durat
ion and high quality, their large number and good spatial distribution
, and the spatially coherent background noise. The two instrumental da
ta types are complementary and provide constraints on the upper-mantle
rheology and on the distribution of ice during the late glacial stage
. Comparisons of the observed rates of change of the water levels with
models for glacial rebound yield earth models with a lithospheric thi
ckness of 80-100 km and an upper-mantle viscosity of (4-5) x 10(20) Pa
s, effective parameters that are consistent with those obtained from
the analysis of the geological evidence for the same region. The mareo
graph results support ice-sheet models in which the Late Weichselian i
ce thickness over the eastern and southern parts of Fennoscandia is re
latively thinner than that for the western region, also consistent wit
h the interpretation of the geological evidence for sea-level change.
In addition, the instrumental records provide constraints on the eusta
tic sea-level change for about the past 100 years. A satisfactory sepa
ration of the earth rheology parameters from this rate of change can b
e achieved by estimating the latter only from those records for which
the predicted isostatic effects are small. A check on these results is
possible by using the lake-level records to establish constraints on
the earth-model parameters and the sea-level records to constrain also
the eustatic change. All approaches lead to an average eustatic sea-l
evel rise for the past century of about 1.1 +/- 0.2 mm yr(-1).