Isostasy, LAB and some properties of asthenosphere in chosen regions of Poland

Abstract

We use programs from the package LABWA2015 to determine position of Lithosphere-Asthenosphere Boundary (LAB) and some properties of lower lithosphere in chosen sites in Poland. Seismic, topographic, thermal and petrological data are used together with assumption about isostasy. Moreover we investigate the role of assumption about the steady state temperature distribution. We have found that sometimes this assumption for continental lithosphere can be unjustified but usually does not lead to significant errors. We have found also that in chosen sites, the thermal LAB is in the depth range 85-95 km. The average value of thermal conductivity of mantle is ~4 W m-1 K-1. Just below MOHO, a level of approximate isostatic compensation is found. More precise compensation is found in the asthenosphere at ~110 km but its position is sensitive to the density distribution.