Paleoclimatology: Second clock supports orbital pacing of the ice ages
For a while, it looked as if a water-filled crack in the Nevada desert might doom the accepted explanation of the ice ages. Twenty years ago, the so-called astronomical theory had carried the day. Oceanographers had found evidence implying that the march of ice ages over the last million years was paced by the cyclical stretching and squeezing of Earth`s orbit around the sun, which would have altered the way sunlight fell on the planet`s surface. But in 1988, researchers scuba diving in Nevada`s Devils Hole came up with a climate record--captured in carbonate deposits in the crack-that seemed to contradict this chronology. This article discusses the findings and the puzzles that still remain. The records of sea-level change in Barbados coral appear to be right and the astronomical theory is on solid ground using a new clock based on the radioactive decay of uranium-235 to protactinium-231. However, the Devils Hole record also seems to be correct.
- OSTI ID:
- 476668
- Journal Information:
- Science, Vol. 276, Issue 5313; Other Information: PBD: 2 May 1997
- Country of Publication:
- United States
- Language:
- English
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Continuous 500,000-year climate record from vein calcite in Devils Hole, Nevada