Evaluation of the ground surface Enthalpy balance from bedrock shallow borehole temperatures (Livingston Island, Maritime Antarctic)

M. Ramos (1) , G. Vieira (2)

1 Department of Physics
2 Centre for Geographical Studies [Lisbon]

The annual evolution of the ground temperatures from Incinerador borehole in Livingston Island (South Shetlands, Antarctic) is studied. The borehole is 2.4 m deep and is located in a quartzite outcrop in the proximity of the Spanish Antarctic Station Juan Carlos I. In order to model the movement of the 0°C isotherm (velocity and maximum depth) hourly temperature profiles from: (i) the cooling periods of the frost seasons of 2000 to 2005, and (ii) the warming periods of the thaw seasons of 2002?2003, 2003?2004 and 2004?2005, were studied. In this modelling approach, heat gains and losses across ground surface are considered to be the causes for the 0°C isotherm movement. A methodological approach to calculate the Enthalpy change based on the thermodynamic analysis of the ground during the cooling and warming periods is proposed. The Enthalpy change is equivalent to the heat exchange through the ground surface during each season, thus enabling to describe the interaction ground-atmosphere and providing valuable data for studies on permafrost and periglacial processes. The bedrock density is considered to be constant in the borehole and initial isothermal conditions at 0°C are assumed to run the model. The final stages correspond to the temperatures at the end of the cooling and warming periods (annual minima and maxima).

Domaines: Interfaces continentales, environnement; Océan, Atmosphère; Sciences de la Terre

M. Ramos, G. Vieira. Evaluation of the ground surface Enthalpy balance from bedrock shallow borehole temperatures (Livingston Island, Maritime Antarctic). The Cryosphere Discussions, 2008, 2 (2), pp.153-184. ⟨hal-00298539⟩