九州南部地域の地殻熱流量の決定 : 串木野及び日南地域

概要

論文の詳細を見る
Two new heat flow values were determined at the Kushikino and Nichinan areas in southern Kyushu, Japan. The Kushikino area exists in the Tertiary volcanic region, where underground temperature was measured by using horizontal boreholes cut in the drifts of the mine and those drilled vertically and directionally from the land surface. By considering the effect of underground water movement to values of geothermal gradients, we determined a high value of 129mW/m^2 (3.07 HFU). Such a high heat flow value is consistent with those observed in other Tertiary to Quaternary volcanic regions of island arcs. At the Nichinan area, we also determined a high value of 94mW/m^2 (2.24 HFU) by using a vertical deep borehole up to 1, 000m. The Nichinan area exists in the Tertiary sedimentary region, which is between the Nankai trough and the volcanic front. It is peculiar that such a high heat flow is found in the non-volcanic region from tectonic point of view. The high heat flow value observed at the Nichinan area may show underground volcanism which is not identified at the surface.
特定非営利活動法人日本火山学会の論文
1985-12-28