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Reports on evidence of past volcanism found in the ice core recovered at Byrd Station Antarctica in 1968. Establishment of three major conditions of volcanic chronology; Continuous acidity curves for several representative depth levels; Chronological record of 57 major high-acid volcanic signals measured from the present back to 50 ka BP.

Presents results from a new deep ice core drilled at the summit of the Greenland ice sheet. Depositional environment and flow pattern of the ice that are ideal for core recovery and analysis; Obtaining high-resolution continuous time series of climate-related parameters; Interstadial episode; Ice core data, including ice-sheet thickness, accumulation rate and mean air temperature; More.

Abstract: A new ice core chronology for the Greenland DYE-3, GRIP, and NGRIP ice cores has been constructed, making it possible to compare the and accumulation signals recorded in the three cores on an almost annual scale throughout the Holocene. We here introduce the new time scale and investigate and accumulation anomalies that are common to the three cores in the Early Holocene (7.9–11.7ka before present). Three time periods with significant and synchronous anomalies in the and accumulation signals stand out: the well-known 8.2ka event, an event of shorter duration but of almost similar amplitude around 9.3ka before present, and the Preboreal Oscillation during the first centuries of the Holocene. For each of these sections, we present a anomaly curve and a common accumulation signal that represents regional changes in the accumulation rate over the Greenland ice cap. [Copyright &y& Elsevier]

Abstract: Twenty ice cores drilled in medium to high accumulation areas of the Greenland ice sheet have been used to extract seasonally resolved stable isotope records. Relationships between the seasonal stable isotope data and Greenland and Icelandic temperatures as well as atmospheric flow are investigated for the past 150–200 years. The winter season stable isotope data are found to be influenced by the North Atlantic Oscillation (NAO) and very closely related to SW Greenland temperatures. The linear correlation between the first principal component of the winter season stable isotope data and Greenland winter temperatures is 0.71 for seasonally resolved data and 0.83 for decadally filtered data. The summer season stable isotope data display higher correlations with Stykkisholmur summer temperatures and North Atlantic SST conditions than with SW Greenland temperatures. The linear correlation between Stykkisholmur summer temperatures and the first principal component of the summer season stable isotope data is 0.56, increasing to 0.66 for decadally filtered data. Winter season stable isotope data from ice core records that reach more than 1400 years back in time suggest that the warm period that began in the 1920s raised southern Greenland temperatures to the same level as those that prevailed during the warmest intervals of the Medieval Warm Period some 900–1300 years ago. This observation is supported by a southern Greenland ice core borehole temperature inversion. As Greenland borehole temperature inversions are found to correspond better with winter stable isotope data than with summer or annual average stable isotope data it is suggested that a strong local Greenland temperature signal can be extracted from the winter stable isotope data even on centennial to millennial time scales. [Copyright &y& Elsevier]

Two deep ice cores from central Greenland, drilled in the 1990s, have played a key role in climate reconstructions of the Northern Hemisphere, but the oldest sections of the cores were disturbed in chronology owing to ice folding near the bedrock. Here we present an undisturbed climate record from a North Greenland ice core, which extends back to 123,000 years before the present, within the last interglacial period. The oxygen isotopes in the ice imply that climate was stable during the last interglacial period, with temperatures 5°C warmer than today. We find unexpectedly large temperature differences between our new record from northern Greenland and the undisturbed sections of the cores from central Greenland, suggesting that the extent of ice in the Northern Hemisphere modulated the latitudinal temperature gradients in Greenland. This record shows a slow decline in temperatures that marked the initiation of the last glacial period. Our record reveals a hitherto unrecognized warm period initiated by an abrupt climate warming about 115,000 years ago, before glacial conditions were fully developed. This event does not appear to have an immediate Antarctic counterpart, suggesting that the climate see-saw between the hemispheres (which dominated the last glacial period) was not operating at this time. [ABSTRACT FROM AUTHOR]

Presents research which used ice cores from Penny Ice Cap, Baffin Island, Canada, to establish a time scale for the end of the Wisconsin ice age. Records found in ice cores; Evidence of pre-Holocene ice; Origin of last glacial maximum (LGM) ice; Suggestion of thick ice frozen to the bed of Hudson Bay.