Icecore research

Ice-cores provide the best palaeoclimatic records for guiding many aspects of human behaviour and policy. Recent advances in ice-core research are numerous and impressive. For example, continuous-flow melters feed samples to inductively coupled plasma mass spectrometry (ICPMS) and other instruments (e.g. McConnell, 2002), producing high time-resolution, accurate histories of an amazing range of soluble, insoluble and even gaseous components (Huber et al., 2003). Analyses of important trace gases such as methyl bromide and methyl chloride produce accurate results at the part-per-trillion level (Saltzman et al., 2004). Isotopic analyses of key species produce new and unexpected insights (e.g. Alexander et al., 2003; Sowers et al., 2003). Biological effects are discovered and identified (e.g. Price, 2000; Campen et al., 2003). Electrical characterization now involves multi-technique, multifrequency, multi-track approaches (Moore et al., 1989; Wilhelms et al., 1998; Taylor & Alley, 2004), and physical techniques include x-ray transmission and others (Freitag et al., 2004). And, we are left with the suspicion that the best is yet to come.

In such a promising situation, the most important need is to obtain more ice (Fig. 72.6), from key places, together with the resources to allow technique development and application. Obviously, drilling has advanced greatly (Azuma & Fujii, 2002), but additional rapid improvement in core-recovery speed and quality is unlikely to be easy. Nonetheless, whether the future lies in refinement of existing drills, testing of new techniques, access drills, sidewall corers, or other technologies, better drilling will undoubtedly pay off in better science.

Major ice cores can now rival satellites in lead times. During a 1988 meeting, the U.S. Ice Core Working Group focused on an inland, high-accumulation-rate site in West Antarctica to follow the GISP2 drilling in central Greenland. The report of that meeting (Ice Core Working Group, 1989) stated 'A long-range ice core research plan for the next decade comprises: a deep core in West Antarctica; drilling to start around 1994-95 . . .' (p. 25). Drilling of that core may start slightly more than a decade after the target date if all goes well. Fortunately, during the time that the main project was logistically precluded, intervening coring at Taylor Dome and Siple Dome has proven valuable. The value of having a suite of drilling targets, with site-selection work well advanced, should be clear.

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