The NorthGRIP ice-core drilling


The 17th of July this year a new ice-core drilling to the bottom of the Greenland ice sheet was terminated at NorthGRIP (75.1°N; 42.3°W; 2917 m asl). The drilling project was initiated in 1996 and took much longer than anticipated due to a stuck drill in the middle of the ice sheet and because the unexpectedly warm ice near the bottom is difficult to recover. However, the resulting 3085 m long ice core provides a unique high-resolution paleoclimatic profile that goes approximately 120.000 years back in time. The ice covers the transition from the previous interglacial period, the Eemian, to the last glacial period with annual layers of centimeter resolution. In contrast to existing Greenland ice cores, the NorthGRIP core is believed to provide a continuous climatic profile for the deepest part of the ice. The high temporal resolution of the ice is due to basal melt, which, in turn, opens up an interesting possibility of sampling undisturbed basal water from NorthGRIPs ‘Lake Vostok.’