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Temperature distribution in karst systems: the role of air and water fluxes
Author(s) -
Luetscher Marc,
Jeannin PierreYves
Publication year - 2004
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/j.1365-3121.2004.00572.x
Subject(s) - karst , geology , vadose zone , geothermal gradient , borehole , phreatic , geothermal heating , infiltration (hvac) , heat flux , cave , lapse rate , geomorphology , hydrology (agriculture) , groundwater , atmospheric sciences , aquifer , geothermal energy , geophysics , heat transfer , geotechnical engineering , meteorology , paleontology , history , physics , archaeology , thermodynamics
A better understanding of heat fluxes and temperature distribution in continental rocks is of great importance for many engineering aspects (tunnelling, mining, geothermal research, etc.). This paper aims at providing a conceptual model of temperature distribution in karst environments which display thermal ‘anomalies’ as compared with other rocks. In temperate regions, water circulation is usually high enough to ‘drain‐out’ completely the geothermal heat flux at the bottom of karst systems (phreatic zone). A theoretical approach based on temperature measurements carried out in deep caves and boreholes demonstrates, however, that air circulation can largely dominate water infiltration in the karst vadose zone, which can be as thick as 2000 m. Consequently, temperature gradients within this zone are similar to the lapse rate of humid air (∼0.5 °C 100 m −1 ). Yet, this value depends on the regional climatic context and might present some significant variations.