The timing of high sea levels over the past 200,000 years

Journal Article · Fri Feb 11 00:00:00 EST 1994 · Science (Washington, D.C.); (United States)

DOI:https://doi.org/10.1126/science.263.5148.796· OSTI ID:6978523

Gallup, C D; Edwards, R L; Johnson, R G ^[1]

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1. Univ. of Minnesota, Minneapolis, MN (United States)

The [sup 230]Th ages and [sup 234]U/[sup 238]U ratios were determined for Barbados corals that grew during periods of high sea level within the last 200,000 years. The similarity of the initial [sup 234]U/[sup 238]U ratios of some of the corals to the modern marine value suggests that these samples are pristine and that the marine [sup 234]U/[sup 238]U ratio 83,000 and 200,000 years ago was within 2 per mil of the modern value. The accuracies of the [sup 230]Th ages are evaluated on the basis of the [sup 234]U/[sup 238]U values and a model of the behavior of uranium and thorium isotopes during diagenesis. For the last three interglacial and two intervening interstadial periods, sea level peaked at or after peaks in summer insolation in the Northern Hemisphere. This overall pattern supports the idea that glacial-interglacial cycles are caused by changes in Earth's orbital geometry. The sea-level drop at the end of the penultimate interglacial, the last interglacial, and a subsequent interstadial period lagged behind the decrease in insolation by 5,000 to 10,000 years.

• OSTI ID: 6978523
• Journal Information: Science (Washington, D.C.); (United States), Vol. 263:5148; ISSN 0036-8075
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
EARTH PLANET
INSOLATION
ORBITS
SEA LEVEL
VARIATIONS
ISOTOPE RATIO
PALEOCLIMATOLOGY
THORIUM 230
URANIUM 234
URANIUM 238
ACTINIDE ISO
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
EVEN-EVEN NUCLEI
HEAVY ION DECAY RADIOISOTOPES
HEAVY NUCLEI
ISOTOPES
LEVELS
MAGNESIUM 28 DECAY RADIOISOTOPES
NEON 24 DECAY RADIOISOTOPES
NUCLEI
PALEONTOLOGY
PLANETS
RADIOISOTOPES
SPONTANEOUS FISSION RADIOISOTOPES
THORIUM ISOTOPES
URANIUM ISOTOPES
YEARS LIVING RADIOISOTOPES
540110*