Conclusions

Differentiating between relict areas that were nunataks and relict areas that were preserved as frozen areas under former ice sheets using cosmogenic nuclide studies provides important information for constraining the extent and characteristics of former ice sheets. The data currently available in northern Sweden (e.g. Fabel et al., 2002, Stroeven et al., 2002a, b) indicate that relict landscapes in interior locations of mid-latitude ice sheets probably have survived many consecutive glacial cycles. This provides an important constraint for inversion models used in reconstructing the dynamics of former mid-latitude ice sheets (see Kleman et al., this volume, Chapter 38). It also provides a key boundary condition for ice sheet models, which must be able to indicate non-erosive basal conditions for these areas during growth, maximum and decay phases of repeated ice sheet glaciations. Similar landscapes in coastal locations may have been nunataks or were covered for substantially shorter time spans in total than the interior sites. Differentiating between these two possibilities requires more rigorous testing with multiple nuclides.

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