Core drilling at Syowa Station, Antarctica

The first core drilling at Syowa Station in Antarctica was carried out by the 21st Japanese Antarctic Research Expedition (JARE-21) by a rotary core drilling method using air as the drilling fluid. After 26 days of drilling work, a 20m-deep borehole was obtained in March 1980. In order to deepen this borehole, the core drilling was succeeded by JARE-22 using water as the drilling fluid. However, drilling rods were stuck in the hole during the removal of the frozen drilling fluid. The part of the hole which is deeper than 5m could not be used for underground temperature measurements. Though a new 30m-deep hole was drilled in March 1981,drilling rods were stuck in the hole again. Only the upper part of the hole which is shallower than 7m could be used for the temperature measurements. Another 30m-deep hole was drilled in January 1982. It was done well to make the 30m-deep hole. However, the hole could not be used for the temperature measurements, because drilling rods were stuck in the hole again during the removal of the drilling fluid. Though the leakage and/or flood of water in the drilling hole on East Ongul Island was beyond prediction, a few cracks at the depth from the surface to 10m were found to act as waterways. To keep water from leakage and/or flood is the most important in the core drilling at Syowa Station