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Jaegyu Knoll is located in Antarctic Sound, between Trinity Pen- insula and islands of the Joinville Island Group, on the northern Antarctic Peninsula (Fig. 1a). Jaegyu Knoll is interpreted as a Holocene submarine intraplate volcano based on its morphology, in situ observations such as bottom videos and high-resolution photographs (Quinones et al. 2005), a rock dredge that recovered fresh volcanic rock (Hatfield et al. 2004) and a measured geother- mal anomaly (Hatfield et al. 2004). All aspects of the knoll are con- sistent with recent volcanic activity, which appears to have been persistent in the northern Antarctic Peninsula region from Meso- zoic times to the present (e.g. Baker et al. 1973; Gonza ́lez-Ferra ́n 1991; Gracia et al. 1997). The knoll, and at least two other smaller volcanic features in Antarctic Sound (Fig. 1a), lie within an over- deepened glacial trough that was presumably sculpted by ice dur- ing the Last Glacial Maximum (LGM; 23–19 ka BP). 

Top-down rather than bottom-up change The Larsen-B Ice Shelf in Antarctica collapsed in 2002 because of a regional increase in surface temperature. This finding, reported by Rebescoet al., will surprise many who supposed that the shelf's disintegration probably occurred because of thinning of the ice shelf and the resulting loss of support by the sea floor beneath it. The authors mapped the sea floor beneath the ice shelf before it fell apart, which revealed that the modern ice sheet grounding line was established around 12,000 years ago and has since remained unchanged. If the ice shelf did not collapse because of thinning from below, then it must have been caused by warming from above. Science, this issue p.1354 

Palmer Deep sediment cores are used to produce the first high-resolution, continuous late Pleistocene to Holocene time-series from the Antarctic marine system. The sedimentary record is dated using accelerator mass spectrometer radiocarbon methods on acid insoluble organic matter and foraminiferal calcite. Fifty-four radiocarbon analyses are utilized in the dating which provides a calibrated timescale back to 13 ka BP. Reliability of resultant ages on organic matter is assured because duplicates produce a standard deviation from the surface age of less than laboratory error (i.e., ±50 years). In addition, surface organic matter ages at the site are in excellent agreement with living calcite ages at the accepted reservoir age of 1260 years for the Antarctic Peninsula. Spectral analyses of the magnetic susceptibility record against the age model reveal unusually strong periodicity in the 400,–200 and 50-70 year frequency bands, similar to other high-resolution records from the Holocene but, so far, unique for the circum-Antarctic. Here we show that comparison to icecore records of specific climatic events (e.g., the ’Little Ice Age‘, Neoglacial, Hypsithermal, and the Bølling/Allerød to Younger Dryas transition) provides improved focus upon the relative timing of atmosphere/ocean changes between the northern anid southern high latitudes.