Glaciology
Deep ice core drilling at Dome F was started in August 1995, and in December 1996 a depth of 2503 m was reached. This first core covers a period back to 340,000 years.
The core quality from the Dome Fuji station, East Antarctica, is excellent even in the brittle zone from 500 to 860 m deep, where the ice is fragile during the 'in situ' core-cutting procedure.
A second deep core was started in 2003. Drilling was carried out during four subsequent austral summers from 2003/2004 until 2006/2007, and by then a depth of 3035.22 m was reached. The drill did not hit the bedrock, but rock particles and refrozen water have been found in the deepest ice, indicating that the bedrock is very close to the bottom of the borehole. This core greatly extends the climatic record of the first core, and, according to a first, preliminary dating, it reaches back until 720,000 years. The ice of the second Dome F core is therefore the second-oldest ice ever recovered, only outranged by the EPICA Dome C core.
Read more about this topic: Dome F