Kohnen station - the drilling camp for the EPICA deep ice core in Dronning Maud Land

The European Project for Ice Coring in Antarctica (EPICA) was a joint European Science Foundation and European Commission scientific programme, funded by the European Union and by national contributions. It aimed in drilling two deep ice cores in Antarctica. Kohnen Station at 75°00'06"S, 0°04'04"E served as the logistic base for drilling the deep EPICA ice core, EDML, in Dronning Maud Land (DML). AWI has been in charge of providing the logistics for the EPICA drilling operations in DML. Kohnen Station was put into operation on January 11, 2001. It is a summer-only base. An extensive pre-site survey had been carried out between 1995 and 1999 to find the site with the best glaciological conditions for deep ice core drilling. Access to Kohnen Station is possible by means of sledge traverses starting from Neumayer Station at the coast or by aircraft support in the frame of the Dronning Maud Land Air Network (DROMLAN). A Comprehensive Environmental Impact Evaluation (CEE) was worked out for the drilling activity. Two austral summer seasons were needed to construct the base as well as the drill and science trench. Kohnen Station itself consists of eleven containers on a steel platform, which serve for power supply, snow melting, kitchen and accommodation. To host up to 27 people movable containers adjacent to the main base are used additionally. The drill and science trench is a 6 m deep trench in the firn covered by a wooden roof. It is fit out with the needed drilling equipment. The drilling operation lasted for four summer seasons. It started in 2001/2002 and was finished on January 16, 2006 at the final drilling depth of 2774.15 m. The technical equipment is described in the paper. Core processing took place at the cold lab of AWI at Bremerhaven as an international effort. In addition to the drilling activities several associated programmes for glaciology, meteorology and air chemistry have been carried out in the vicinity of Kohnen Station. A short summary with scientific results of the investigations at the EDML ice core is presented.