Dependence of the surface heat flow on the radioactivity of the Earth

摘要: It is well known that the earth's surface heat flow in approximate balance with production an earth of chondritic composition. The ratio K/U crustal rocks and peridotite, dunite, eclogite about 1×104, contrast to chondrites 7.5×104. present computations show models having a U concentration 3 or 4 times observed meteorites = 104 yield flow, provided initial temperature was order 1000°C less. In models, ratios Th/U are assumed constant throughout equal 1×104 3.7, respectively. Three radial distributions radioactive material studied: (1) uniform distribution mantle, (2) oceanic structure upper 1500 km above 465 km, (3) continental marked 45 km. give average mantle lies between 5× 0−8 g g−1 at depth 1000°C. An 5.5×10−8 will produce melting excess observed. With these structures, calculations clearly implies unless thermal conductivity increases substantially depth. problems development gradient nonradioactive sources remain unsolved.