1) Three indices of global climate have been monitored in the record of the past 450,000 years in Southern Hemisphere ocean-floor sediments. 2) Over the frequency range 10(-4) to 10(-5) cycle per year, climatic variance of these records is concentrated in three discrete spectral peaks at periods of 23,000, 42,000, and approximately 100,000 years. These peaks correspond to the dominant periods of the earth's solar orbit, and contain respectively about 10, 25, and 50 percent of the climatic variance. 3) The 42,000-year climatic component has the same period as variations in the obliquity of the earth's axis and retains a constant phase relationship with it. 4) The 23,000-year portion of the variance displays the same periods (about 23,000 and 19,000 years) as the quasi-periodic precession index. 5) The dominant, 100,000-year climatic [See table in the PDF file] component has an average period close to, and is in phase with, orbital eccentricity. Unlike the correlations between climate and the higher-frequency orbital variations (which can be explained on the assumption that the climate system responds linearly to orbital forcing), an explanation of the correlation between climate and eccentricity probably requires an assumption of nonlinearity. 6) It is concluded that changes in the earth's orbital geometry are the fundamental cause of the succession of Quaternary ice ages. 7) A model of future climate based on the observed orbital-climate relationships, but ignoring anthropogenic effects, predicts that the long-term trend over the next sevem thousand years is toward extensive Northern Hemisphere glaciation.

http://science.sciencemag.org/content/sci/194/4270/1121.full.pdf

Variations in the Earth's Orbit: Pacemaker of the Ice Ages

http://ocp.ldeo.columbia.edu/res/div/ocp/pub/martinson/martinson87.pdf

Age dating and the orbital theory of the ice ages: Development of a high-resolution 0 to 300,000-year chronostratigraphy

From the time that detailed oxygen isotope records derived from foraminifera living in the constant-temperature environment of the abyssal ocean became available, there has been a discrepancy between the ice volume record that these records imply, and that derived from the altitude of dated coral terraces around the world. Here, we re-examine the data and conclude that the temperature of the abyssal ocean has been an actively varying component of the climate system.

Oxygen isotopes and sea level

Ocean Drilling Program (ODP) Site 677 provided excellent material for high resolution stable isotope analysis of both benthonic and planktonic foraminifera through the entire Pleistocene and upper Pliocene. The oxygen isotope record is readily correlated with the SPECMAP stack (Imbrieet al.1984) and with the record from DSDP 607 (Ruddimanet al.1986) but a significantly better match with orbital models is obtained by departing from the timescale proposed by these authors below Stage 16 (620 000 years). It is the stronger contribution from the precession signal in the record from ODP Site 677 that provides the basis for the revised timescale. Our proposed modification to the timescale would imply that the currently adopted radiometric dates for the Matuyama–Brunhes boundary, the Jaramillo and Olduvai Subchrons and the Gauss–Matuyama boundary underestimate their true astronomical ages by between 5 and 7%.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0263593300020782

An alternative astronomical calibration of the lower Pleistocene timescale based on ODP Site 677

An oxygen and carbon isotopic history based on analyses of benthonic and planktonic foraminifera in three overlapping subantarctic sections is presented for the last 55 m.y. with a sampling interval ofless than 1 m.y. Surface temperature at Site 277, on the Campbell Plateau, was about 19°C in the early Eocene, about 13°C in the middle Eocene, about 11°C in the late Eocene, and about 7°C in the Oligocene. Declines in temperature appear to have been rather rapid and are separated by episodes of relative temperature stability. Bottom temperature at Site 277 was about 1°C below surface temperature in the Paleocene and about 2°C below surface temperature in the Oligocene. Site 279, on the Macquarie Ridge, records an early Miocene warming of over 2°C followed by a cooling and a second similar temperature rise in the middle Miocene. Bottom temperature at this somewhat deeper site was about 3°C below surface temperature and was probably as low as 4°C during part of the early Miocene. Comparisons between Sites 277 and 279 suggest that from the early Oligocene temperatures of deep water were low like the present day, implying that the mean annual temperature in high southern latitudes was near freezing by the beginning of the Oligocene (but certainly no earlier). From this time glaciers would have descended to sea level, and there would have been sea-ice production. If an ice sheet were present, it could not have been more than a small fraction of its present-day size. Site 281, on the South Tasman Rise, extends the record into the middle and late Miocene during which time the major East Antarctic ice sheet accumulated. A significant rise in surface temperature during the late Miocene did not cause the melting of this ice sheet, demonstrating that by this time it had already achieved its present invulnerability to climatic change. Since temperatures during much of the Miocene were significantly above any Pleistocene values, it is extremely unlikely that any climatic change in the geologically near future will significantly affect the stability of the East Antarctic ice sheet.

Paleotemperature history of the Cenozoic and the initiation of Antarctic glaciation : Oxygen and carbon isotope analyses in DSDP Sites 277,279, and 281

Oxygen isotope and palaeomagnetic stratigraphy of Equatorial Pacific core V28-238: Oxygen isotope temperatures and ice volumes on a 105 year and 106 year scale☆

Neil D Opdyke

Papers

Oxygen isotope and palaeomagnetic stratigraphy of Equatorial Pacific core V28-238: Oxygen isotope temperatures and ice volumes on a 105 year and 106 year scale☆

Oxygen isotope and paleomagnetic stratigraphy of sediment core V28-239

Stable oxygen isotope analysis on sediment core V28-238