Method for deep temperature estimation with regard to the paleoclimate influence on heat flow

Abstract

New results of the study of the distorting effect of paleoclimate on the formation of the thermal field of the Earth’s uppermost crust inthe South Urals are presented. We discuss some consequences of taking into account the paleoclimate influence on estimates of deep heat flow and possible applications of these data. The dependence of the heat flow density on the studied depth of boreholes is considered, and deep heat loss and deep temperatures are estimated. A new method for deep temperature estimation is proposed, which takes into account the paleoclimate influence on the heat flow. The method is tested on the available high-quality temperature data for deep boreholes. Deep temperatures to a depth of –10,000m are estimated for the platform part of the Republic of Bashkortostan using the proposed method. Isotherm schemes are constructed for elevations of –5000 and –10,000m below sea level.The necessity of using heat flow values corrected for the paleoclimate influence to estimate the Earth’s thermal state is justified. Some examples illustrate that underestimation of heat flow values measured in shallow boreholes might lead to underestimation of deep temperatures and global heat losses.