Thermal springs are widespread in the European Alps, with hundreds of geothermal sites known and exploited. The thermal circulation and fluid outflows were examined in the area around Bormio (Central Italian Alps), where ten geothermal springs discharge from dolomite bodies located close to the regional Zebrù thrust. Water is heated in deep circulation systems and upwells vigorously at a temperature of about 40 °C. Heat and fluid transport is explored by steady and transient three-dimensional finite-element simulations taking into account the effect of the last glaciation, which in the study area was recognized to end around 11,000–12,000 years ago. The full regional model (ca. 700 km2) is discretized with a highly refined triangular finite-element planar grid. Numerical simulations suggest a reactivation of the system following the end of the Last Glacial Maximum. Results correctly simulate the observed discharge rate of ca. 2,400 L/min and the spring temperatures after ca. 13,000 years from deglaciation, and show a complete cooling of the aquifer within a period of approximately 50,000 years. Groundwater flow and temperature patterns suggest that thermal water flows through a deep system crossing both sedimentary and metamorphic lithotypes along a fracture network associated with the thrust system. This example gives insights into the influences of deep alpine structures and glaciations on groundwater circulation that control the development of many hydrothermal systems not necessarily associated with convective heat flow.

Volpi, G., Magri, F., Frattini, P., Crosta, G., Riva, F. (2017). Groundwater-driven temperature changes at thermal springs in response to recent glaciation: Bormio hydrothermal system, Central Italian Alps. HYDROGEOLOGY JOURNAL, 25(7), 1967-1984 [10.1007/s10040-017-1600-6].

Groundwater-driven temperature changes at thermal springs in response to recent glaciation: Bormio hydrothermal system, Central Italian Alps

Volpi, Giorgio
;
Frattini, Paolo;Crosta, Giovanni;Riva, Federico
2017

Abstract

Thermal springs are widespread in the European Alps, with hundreds of geothermal sites known and exploited. The thermal circulation and fluid outflows were examined in the area around Bormio (Central Italian Alps), where ten geothermal springs discharge from dolomite bodies located close to the regional Zebrù thrust. Water is heated in deep circulation systems and upwells vigorously at a temperature of about 40 °C. Heat and fluid transport is explored by steady and transient three-dimensional finite-element simulations taking into account the effect of the last glaciation, which in the study area was recognized to end around 11,000–12,000 years ago. The full regional model (ca. 700 km2) is discretized with a highly refined triangular finite-element planar grid. Numerical simulations suggest a reactivation of the system following the end of the Last Glacial Maximum. Results correctly simulate the observed discharge rate of ca. 2,400 L/min and the spring temperatures after ca. 13,000 years from deglaciation, and show a complete cooling of the aquifer within a period of approximately 50,000 years. Groundwater flow and temperature patterns suggest that thermal water flows through a deep system crossing both sedimentary and metamorphic lithotypes along a fracture network associated with the thrust system. This example gives insights into the influences of deep alpine structures and glaciations on groundwater circulation that control the development of many hydrothermal systems not necessarily associated with convective heat flow.
Articolo in rivista - Articolo scientifico
Glaciation; Groundwater and heat flow; Italy; Numerical modeling; Thermal conditions;
Glaciation; Groundwater and heat flow; Italy; Numerical modeling; Thermal conditions; Water Science and Technology; Earth and Planetary Sciences (miscellaneous)
English
2017
25
7
1967
1984
none
Volpi, G., Magri, F., Frattini, P., Crosta, G., Riva, F. (2017). Groundwater-driven temperature changes at thermal springs in response to recent glaciation: Bormio hydrothermal system, Central Italian Alps. HYDROGEOLOGY JOURNAL, 25(7), 1967-1984 [10.1007/s10040-017-1600-6].
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/176098
Citazioni
  • Scopus 11
  • ???jsp.display-item.citation.isi??? 11
Social impact