oxygen-isotope curve
oxygen-isotope curve A graphical plot of values for the relative proportions of two isotopes of oxygen. Oxygen can exist in several isotope forms, but only 16O and 18O are important in the analysis of oxygen isotopes (see OXYGEN-ISOTOPE RATIO). In nature, the present-day average ratio of 18O to 16O is about 1: 500, and measurements are made against this value as a standard. There is now evidence that this ratio changed in ocean waters in a cyclical fashion in succeeding glacial and interglacial periods (see OXYGEN-ISOTOPE ANALYSIS). At the height of the last (Devensian) glaciation it appears that deep-ocean waters may have been enriched in 18O by about 1.6 parts per thousand. This would be equivalent to a lowering of sea level of about 165 m compared to the present level.
More From encyclopedia.com
O , O, o [Called ‘oh’]. The 15th LETTER of the Roman ALPHABET as used for English. It originated as the Phoenician consonant symbol 'ain, representing a… Oxygen-isotope Analysis , oxygen-isotope analysis Method for estimating past ocean temperatures. The ratio of the stable oxygen isotopes, 18O and 16O, is temperature dependent… Homeotherm , ho·me·o·therm / ˈhōmēəˌ[unvoicedth]ərm/ (also ho·moi·o·therm) • n. Zool. an organism that maintains its body temperature at a constant level, usually… Hydrothermal Vents , Hydrothermal vents are places where hot fluids (up to 752°F [400°C]) related to volcanic activity are released from the ocean floor. Because of the h… Eugene (gladstone) Oneill , Eugene O'Neill (1888-1953) was among the foremost dramatists of the America theater. His main concern was with the anguish and turmoil that wrack the… Will-o-the-wisp , will-o'-the-wisp / ˈwil ə [voicedth]ə ˈwisp/ • n. an ignis fatuus. ∎ fig. a person or thing that is difficult or impossible to find, reach, or catch.…
You Might Also Like
NEARBY TERMS
oxygen-isotope curve