The core barrel is hoisted to the surface, and the core removed; the barrel is lowered again and reconnected to the drill assembly. The well becomes about 10 m deeper each year, so micrometeorites collected in a given year are about years older than those from the previous year. Effective microbial degradation of labile organic matter and in situ contribution of organic matter derived from the microbes themselves are both evident in the sediments. These include plans to: Replicate cores were successfully retrieved at WAIS divide in the — drilling season, at four different depths. Dragging them down the length of the core, and recording the conductivity at each point, gives a graph that shows an annual periodicity. The cause of this increase was possibly due to a very high energy solar proton event Usoskin et al.
Further back there are floating sequences of one to several thousand years of crossdated tree rings that cover parts of the last 20k years.
If the date of the eruption is not known, but it can be identified in multiple cores, then dating the ice can in turn give a date for the eruption, which can then be used as a reference layer. The need for a string of drillpipe that extends from the surface to the bottom of the borehole can be eliminated by suspending the entire downhole assembly on an armoured cable that conveys power to the downhole motor. Folks are generally self-absorbed and self-interested, but folks are also generally good. Journal of Geophysical Research: Core quality was poor, but some scientific work was done on the retrieved ice.