In-Situ Examination of Ice Stratrigraphy and Organic Material in the Lake Vostok Borehole

Investigation of microbial and biochemical content in the deep ice cores from Lake Vostok has excited the scientific and public community and led to consideration of very low metabolic rate, long time period biochemical processes at near water-freezing temperatures. Our laboratory team has been involved in considerations of potential future opportunities to investigate Lake Vostok utilizing deep UV fluorescence and UV Raman instrumentation to locate and classify organic material in the oldest (deepest) meteoric ice (3300 m depth region) and in the differing regions of the accretion ice above the roof of the lake water. We have designed a probe that may be able to be inserted into the existing Vostok 5G drill hole and could provide high spatial imaging of the borehole wall along with examination of possible organic material imbedded within the ice near the wall. The drill fluid utilized by the Vostok drill team and still present in the hole limits the sensitivity and capabilities for detection of in-situ material. It appears that the same fluid will not affect visible light examination of the structures and stratigraphy of the ice layers. UV fluorescence data from several Vostok ice cores (3308, 3562 and 3564 m depth) that are resident at the U.S. National Ice Core Laboratory (USGS-Denver) will be presented and discussed, as well as the case for a new approach to examining the bio-cleanliness of instrumentation that might eventually be inserted for examination of the Lake and sediment bed.