Introduction

This chapter traverses the growth in knowledge and understanding of Antarctic Ice Sheet history through the Cenozoic Era over the last 100 years and briefly considers the future. Important external influences on progress have been the advances in biostratigraphy and geochronology through the latter part of the last century, seismic stratigraphy and deep-sea isotopic studies world-wide over the last four decades, and the marked progress in modelling ice behaviour along with other components of the Earth system over the last two decades. Key events in this account are given in Table 3.1.

Interest in the climate history of the Antarctic continent first developed with the curiosity-driven scientific expeditions from the Northern Hemisphere beginning in the late nineteenth century (the ''Heroic Era'', Fogg, 1992, p. 108ff). These included prominent explorers and scientists from Belgium, Britain, France, Germany, Japan, Norway and the United States and within two decades the extent and salient features of the present ice sheet and the continent beneath had been documented. These included:

(i) An ice sheet of around 5 million square miles (13 million square kilometers) in area and rising to an elevation of at least 10,000 ft (3,000 m), along with shelf and sea ice. In terms of its history, it was thought most likely to have been more extensive in warmer Pliocene times, and to have originated in Miocene times (Taylor, 1922), though Wright and Priestley (1922, Table 17) noted Antarctic glaciation ''apparently began there in Eocene or Oligocene times'';

(ii) Flat-lying ''cover beds'' similar to those in the Transantarctic Mountains (Beacon Sandstone of Late Paleozoic age), with fossil plants similar to those in India, South Africa and South America, indicating a former temperate climate in those times (Seward, 1914);

(iii) An East Antarctic ''shield'', with a foundation of Precambrian rocks and a faulted Ross Sea margin comparable to that of eastern Australia. West Antarctica was seen geologically as more related to southern South America and linked to it through the Scotia Arc (David, 1914).

The decades that followed saw extensive inland exploration largely by the Byrd expeditions (Fogg, 1992, pp. 134-146), with detailed observations of weather, snow and ice cover and some geological observations, but there was little advance in comprehending the basic geological history of the continent. However, there were significant advances in technology and logistics through the introduction of radio communication, seismic sounding, ships and aircraft. These advances prepared the way for US Operation Highjump

Table 3.1: Events in progress in the evolution of antarctic glacial history.

Date

Event

References

1964-1970

1972

1970-1973

1910-1912 Scale of Antarctic Ice Sheet recognized. Simple history proposed. Origin thought likely Miocene but possibly Eocene-Oligocene 1928-1947 Inland exploration/technology development by Byrd expeditions 1957-1964 International Geophysical Year (IGY)

supports extensive geophysical exploration but still the lack of geological record between Jurassic and late Quaternary time. Glacial features mapped in McMurdo region thought Quaternary Miocene radiometric ages indicate pre-Quaternary glaciation a reality. Oligocene ice rafting in Southern Ocean Pre-Quaternary history thought likely from

Northern Hemisphere record Recognition of widespread pre-Quaternary glacial deposits (Sirius Formation) on land in high Transantarctic Mountains Early seismic surveys of continental shelf by

USNS Eltanin First drilling on shelf, showing Antarctic continental glaciation as old as 25 Ma (DSDP Leg 28) Drilling in deep-sea floor showing cooling and first ice sheet at 34 Ma and present ice sheet dating from ~14Ma (DSDP Leg 29) 1973-1975 First onshore scientific drilling (McMurdo Dry Valleys) leading to late Neogene glacial record going back at least 4 Ma in Taylor Valley. First attempt at drilling from floating ice (DVDP 15)

1978 Collapse of West Antarctic Ice Sheet projected from rising CO2 1978-1980 First hole drilled through the Ross Ice Shelf (J9). Sea floor cores recover early Miocene diamict with diatomite clasts and pollen 1982 Early simple Antarctic Ice Sheet model

1984 Marine diatoms in glacial deposits of high

Transantarctic Mountains (Sirius Fm) suggest East Antarctic interior seas b 3 Ma ago Results from first extensive multichannel seismic survey of the Antarctic margin (R/V S.P. Lee, Ross Sea and Wilkes Land)

Wright and Priestley (1922), Taylor (1914, 1922) Fogg (1992)

Craddock et al. (1964), Margolis and Kennett (1970), Flint (1971)

Mercer (1972), Mayewski (1975)

Houtz and Meijer (1970) Hayes, Frakes et al. (1975)

Kennett, Houtz et al. (1975)

Mercer (1978)

Clough and Hansen (1979), Webb et al. (1979)

Oerlemans (1982) Webb et al. (1984), Harwood (1986)

Cooper and Davey (1985), Eittrem and Hampton (1987)

Table 3.1: (Continued).

Date

Event

References

1986-

1988

New drilling results from Ross Sea (CIROS) and Prydz Bay (ODP Leg 119) show cyclicity in early history and ice-sheet antiquity

Barrett (1989), Barron, Larsen et al. (1989)

1987

Vostok ice core provides climate record through last glacial cycle

Barnola et al. (1987)

1986-

1996

Formation of the SCAR Group of Specialists on the Evolution of Cenozoic Palaeoenvironments of the Southern High Latitudes

Webb (1990)

1988-

2002

Formation of ANTOSTRAT - Antarctic Offshore Acoustic Stratigraphy to coordinate Antarctic margin studies

Cooper et al. (2002, this volume)

1993

Ice-sheet model and deep-sea isotope record inconsistent with major Pliocene deglaciation

Pre-mid-Miocene age for Sirius deposits proposed on basis of ancient ash and persistent cold in high Transantarctic Mountains

Huybrechts (1993), Kennett and Hodell (1993) Sugden et al. (1993)

1997-

1999

Cape Roberts cores yield high-resolution record of significant orbitally forced fluctuations in Antarctic Ice Sheet and sea level from 34 to 17 Ma and slight cooling over that period

Naish et al. (2001), Barrett (2007)

2000

New drilling results from Prydz Bay (ODP Leg 188)

O'Brein et al. (2001)

2001

Erice workshop reviews ANTOSTRAT and proposes new group to integrate geophysical/ geological data on Antarctic glacial history and the new generation of coupled ice-ocean-atmosphere models (ACE)

Cooper et al. (2002)

2003

Coupled ocean-atmosphere-ice-sheet model shows major role for CO2 in early ice-sheet formation

DeConto and Pollard (2003)

2004

EPICA yields Dome C climate record through last 8 glacial cycles Formation of ACE as a SCAR Scientific Research Program

EPICA (2004) Siegert et al. (2004)

2005

Landscape evolution model for Lambert drainage basin shows similar fluvial and glacial influence

Jamieson et al. (2005)

2006-

2007

ANDRILL results provide first continuous record of late Antarctic Cenozoic history, including first proximal record of mid-Miocene transition, and evidence of ice-free Ross embayment 3-4 Ma ago

Naish et al. (2008a), Harwood et al. (2003)

immediately following World War II. Although largely a polar training exercise, it provided much of the technological foundation for the International Geophysical Year (IGY) in Antarctica (1957-1958).

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