HR: 1020h
AN: PP52A-0647    [Abstracts]
TI: Paleoclimate on the Kola Peninsula (Russia) From Inversion of Subsurface Temperatures: Role of Weichselian Glaciation
AU: Mottaghy, D
EM: d.mottaghy@geophysik.rwth-aachen.de
AF: RWTH Aachen, Lochnerstr. 4-20, Aachen, D-52056 Germany
AU: * Rath, V
EM: v.rath@geophysik.rwth-aachen.de
AF: RWTH Aachen, Lochnerstr. 4-20, Aachen, D-52056 Germany
AB: Using an extensive data set of temperature logs and thermal properties from the Kola super-deep borehole and 20 shallow boreholes (up to 1.6 km) from its immediate vicinity, we present results from inversions for ground surface temperature histories. We apply a versatile 1-D inversion technique based on a finite-difference approach in order to take into account the heterogeneity of thermal properties and their nonlinear dependence on temperature including freezing and thawing. Regularization of this generally ill-posed problem is achieved by Tikhonov regularization of variable order. The scheme is easily generalized for use with multiple boreholes. Due to excellent database with respect to thermal conductivity (more than 3400 measurements), we were able to determine GST histories back to 50 kY BP. The temperature change from the last glaciation period to the Holocene is smaller (5-6 K) than in lower latitudes, suggesting the existence of an insulating ice cover for a considerable time. This is demonstrated by results 0 north-east Poland. The duration and extent of the glaciation is a matter of discussion, in particular concerning the conditions at its base. We will discuss these question including the sensitivity with respect to general atmospheric climatic conditions.
DE: 1610 Atmosphere (0315, 0325)
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1626 Global climate models (3337, 4928)
DE: 1631 Land/atmosphere interactions (1218, 1843, 3322)
DE: 4920 Dendrochronology
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005