The invention relates to the field of geophysical methods for studying the earth's crust, namely to the assessment of the distribution of the earth's crust temperature with depth. The method determines the depth of a previously unknown geothermal curtain that divides the earth's crust into two parts: a zone of solar energy accumulation (the near-surface part of the earth's crust) and a zone of energy accumulation coming from the earth's interior. The system for determining the depth of the geothermal curtain consists of two spaced groups of temperature sensors. Based on the readings of the temperature sensors, two empirical equations are compiled, the joint solution of which gives the exact location of the geothermal curtain. The method allows the creation of a monitoring system for long-term forecasting of climate change and the cryosphere regime.