| Abstract |
In steep terrain the effect of advective flow can be significant, as it can distort the temperature field in the upper brittle crust. The effect was studied by modelling advective flow across a large valley system in Tibet which is associated with several geothermal hot spring systems, the Yanbajing Valley. It was found that, in this setting, all near-surface temperature gradients are significantly disturbed, attaining values differing by up to half an order of magnitude from those resulting from conductive heat transfer. Allowing for advective effects, it was found that the crustal heat flux within the Himalayan Geothermal Belt lies within the range of 60 to 90 mW/m2 in the Lhasa- Yanbajing area. |