Fluxo de calor, fusão do gelo e nível do mar

SUMMARY The recent values of heat flow data obtained for Greenland and West Antarctica are higher than it was supposed. In West Antarctica, values higher than 200mW/m2 were found (Schroeder et al,2014) and in Greenland, values higher than 140 mW/m2 were detected in the Central part (Petrunin et al,2...

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Bibliographic Details
Main Author: Duque, Maria Rosa
Format: Lecture
Language:Portuguese
Published: APMG 2015
Subjects:
Online Access:http://hdl.handle.net/10174/15737
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Summary:SUMMARY The recent values of heat flow data obtained for Greenland and West Antarctica are higher than it was supposed. In West Antarctica, values higher than 200mW/m2 were found (Schroeder et al,2014) and in Greenland, values higher than 140 mW/m2 were detected in the Central part (Petrunin et al,2013). Thermal conductivity values of ice are relatively low at atmospheric pressure. This means that if we consider heat flowing by conduction, near the surface of the globe, with this heat flow values, the thermal gradients mill be elevated. A possible reason presented for the high heat flow values in Greenland is the existence of a thin lithosphere. The study of the ice melting near the poles is related with the changes in sea level. The obtention of this parameter is difficult, Tide gauges, isostatic adjustment ,plate tectonics, episodes related with local climate, can mask the value of the parameter needed. The time interval with measurement is not enough to obtain clear information about the past. The precision of the measurements made today is very different from the ancient values .Turning again to the heat flow values ,its spatial distribution shows clearly zones in the oceans with high heat flow values. How can this heat influence water movements in that regions? There are clearly lateral discontinuities. How can this influence the temperature of the oceans?