Terrestrial heat flow in the natural steam field at Larderello

Summary Measurements of thermal gradients and rock conductivity in the steam field of Larderello, along a cross section of about 12 km length, reveal a great anomaly of terrestrial heat flow. Heat flow varies between 6 and 14 cal-cm² sec, while thermal gradients are between 200 and 800 deg C-km. The measurements show that heat flow values characterize better the productive areas than thermal gradient anomalies. Knowing the heat flow it is possible to set up the thermal balance of the steam producing area, which is of considerable importance in planning the production of the steam field.