HEAT FLOW IN-SITU MEASUREMENT AT YAP TRENCH OF THE WESTERN PACIFIC

To investigate the geothermal distribution on the two sides of the subduction zone along the Yap trench-arc system in the Western Pacific, the latest Lister heat flow probe was employed for in-situ measurement of heat flow aboard the "kexue" research vessel during the Haishan cruises to this area from January to March, 2015. A total of ten heat flow points was measured across the subduction zone of Yap trench. However, only eight effective data were successfully obtained. The results show that the geothermal gradient of this area ranges from 0.011 Km^-1 to 0.137 Km^-1, with an average of 0.089 Km^-1, the thermal conductivity ranges from 0.58 Wm^-1K^-1 to 1.32 Wm^-1K^-1, and value of heat flow ranges from 14.4 mWm^-2 to 118.85 mWm^-2, with an average of 68.02 mWm^-2. The geothermal distribution indicates that values of heat flow in the area are really quite high. Low heat flow is found in the Parece Vela ocean basin. There is a distribution tendency that the heat flow gradually reduces from the axis of Yap arc to either side. Due to the heat flow data for the region is still scarce, more scientific problems will be further researched.