A search in north Greenland for a new ice-core drill site

摘要: A new deep ice-core drilling site has been identified in north Greenland at 75.12°N, 42.30°W, 316 km north-northwest (NNW) of the GRIP drill on summit ice sheet. The thickness here is 3085 m; surface elevation 2919 m. North (NGRIP) so that Eemian age (115-130 ka BP, calendar years before present) located as far above bedrock possible and layer great possible. An ice-flow model, similar to one used date core, simulate flow along NNW-trending ridge. Surface elevations, accumulation-rate distribution ratio-echo sounding ridge have model input. accumulation rate drops from 0.23 m equivalent year -1 0.19 50 GRIP. Over following 300 relatively constant, starts decreasing again further north. Ice up 3250 bring temperature basal pressure-melting point 100-250 NGRIP a region where smooth . modeled always few degrees below point. Internal radio-echo horizons can be traced between sites, allowing us down 2300 depth (52 BP). predicts Eemian-age will range 2710-2800 m, which 285 bedrock. This 120 bedrock, 20 thicker, than site.