Heat-flow distribution in Southeast Asia with consideration of volcanic heat

As of 1995, in Southeast Asia, from 15 degrees S to 25 degrees N and from 90 to 160 degrees E, 2539 heat flow measurements are available. Despite a recent increase in the number of measurements, still important data gaps exist in the region, especially around the volcanic regions. So far the contribution of heat flux from active volcanoes has largely been overlooked in regional heat-flow maps because of uncertainties surrounding it. We have tried to estimate the volcanic heat in this region with the assumption that these volcanoes emit a similar amount of heat as those in northeast Honshu, Japan, where heat-flow studies and seismic tomography enable us to estimate that, as a first approximation, a volcano can be represented by 140 mW/m(2) of heat flow. A heat-flow map including volcanic heat estimated in this way, makes the heat flow in the Sunda Are and the Philippines, where conventional heat-flow data are scarce, much higher than on a map without the volcanic heat.