Interhemispheric Correlation of Late Pleistocene Glacial Events

Abstract

A radiocarbon chronology shows that piedmont glacier lobes in the Chilean Andes achieved maxima during the last glaciation at 13,900 to 14,890, 21,000, 23,060, 26,940, 29,600, and >/=33,500 carbon-14 years before present ((14)C yr B.P.) in a cold and wet Subantarctic Parkland environment. The last glaciation ended with massive collapse of ice lobes close to 14,000(14)C yr B.P., accompanied by an influx of North Patagonian Rain Forest species. In the Southern Alps of New Zealand, additional glacial maxima are registered at 17,720(14)C yr B.P., and at the beginning of the Younger Dryas at 11,050 (14)C yr B. P. These glacial maxima in mid-latitude mountains rimming the South Pacific were coeval with ice-rafting pulses in the North Atlantic Ocean. Furthermore, the last termination began suddenly and simultaneously in both polar hemispheres before the resumption of the modern mode of deep-water production in the Nordic Seas. Such interhemispheric coupling implies a global atmospheric signal rather than regional climatic changes caused by North Atlantic thermohaline switches or Laurentide ice surges.

Terrigenous Sediment Supply in the Polar to Temperate South Atlantic: Land-Ocean Links of Environmental Changes during the Late Quaternary

“…In contrast to East Antarctica, where intense iceberg calving is related to interglacial stages, maximum iceberg calving rates from Patagonia and the Antarctic Peninsula document the rapid disintegration of marine ice masses during climate amelioration associated with glacial terminations and less pronounced during short-term climate perturbations (Hofrnann 1999;Diekmann et al 2000). Patagonian land records are consistent with these findings and moreover suggest interhemispheric teleconnections with northernhemispheric climate dynamics (Lowell et al 1995;Heusser et al 2000;McCulloch et al 2000).…”

Stratigraphy and chronology of a 15 ka sequence of multi‐sourced silicic tephras in a montane peat bog, eastern North Island, New Zealand

“…Ultimately, the chrono-tephrostratigraphy reported here will underpin attempts to correlate short-term regional or global paleoclimatic changes for the lateglacial and Holocene periods, and especially to determine the degree of synchrony of such changes between Northern and Southern Hemispheres, including the Younger Dryas chron (e.g., Lowell et al 1995;Bjorck et al 1996;Newnham & Lowe in prep.). The chronostratigraphic framework that we have established for the Kaipo sequence is based on 34 reliable ages comprising 20 site-specific radiocarbon ages together with 14 mean ages on the tephra layers, which were derived from other North Island sites using tephrochronology.…”

Glacial‐interglacial trench supply variation, spreading‐ridge subduction, and feedback controls on the Andean margin development at the Chile triple junction area (45–48°S)

“…The survey carried out by the R/V L'Atalante helps to better address the problem of mass transfer in the case of the subduction of an active spreading center and examine the main factors determining the tectonic regime of the continental margin. [Behrmann et al, 1994] [Lowell et al, 1995]. Since that time, the ice cap retreated to its present distribution, restricted to the North and South Patagonian ice fields.…”