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Social and Behavioral Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

2000

University of Wollongong

GeoQuest

Articles 1 - 3 of 3

Full-Text Articles in Social and Behavioral Sciences

Coral Microatolls From The Central Pacific Record Late Holocene El Nino, Colin Woodroffe, Michael K. Gagan Jan 2000

Coral Microatolls From The Central Pacific Record Late Holocene El Nino, Colin Woodroffe, Michael K. Gagan

Faculty of Science, Medicine and Health - Papers: part A

Microatolls are discoid corals that have grown laterally because vertical growth is constrained by exposure at lowest tides. We demonstrate that a modern reef-flat Porites microatoll from Christmas (Kiritimati) Island preserves an oxygen isotope record of substantial sea surface temperature variations related to El Niño-Southern Oscillation (ENSO). We also show that a late Holocene fossil microatoll from the centre of the island contains interannual oxygen isotope variations over an approximate 20-year period. Three pronounced negative isotope anomalies attributed to warm El Niño events are superimposed on an annual cycle. El Niño events similar to those seen in recent decades appear ...


Positionally Dependent 15n Fractionation Factors In The Uv Photolysis Of N2o Determined By High Resolution Ftir Spectroscopy, Fred Turatti, D W. T Griffith, Stephen Wilson, Michael Esler, T Rahn, H Zang, G A. Blake Jan 2000

Positionally Dependent 15n Fractionation Factors In The Uv Photolysis Of N2o Determined By High Resolution Ftir Spectroscopy, Fred Turatti, D W. T Griffith, Stephen Wilson, Michael Esler, T Rahn, H Zang, G A. Blake

Faculty of Science, Medicine and Health - Papers: part A

Positionally dependent fractionation factors for the photolysis of isotopomers of N2O in natural abundance have been determined by high resolution FTIR spectroscopy at three photolysis wavelengths. Fractionation factors show clear 15N position and photolysis wavelength dependence and are in qualitative agreement with theoretical models but are twice as large. The fractionation factors increase with photolysis wavelength from 193 to 211 nm, with the fractionation factors at 207.6 nm for 14N15N16O, 15N14N16O and 14N14N18O equal to −66.5±5‰,−27.1±6 ...


A New Early Devonian Operculate Tetracoral Genus From Eastern Australia, Anthony J. Wright Jan 2000

A New Early Devonian Operculate Tetracoral Genus From Eastern Australia, Anthony J. Wright

Faculty of Science, Medicine and Health - Papers: part A

Chakeola, a solitary latest Lochkovian to late Emsian (Early Devonian) new genus of the operculate tetracoral family Calceolidae, is characterised by: opercular septa that are present from adjacent to the median septum to the lateral extremities of the operculum; a lack of rootlets on the counter face of the corallite; a weak counter opercular face in mature specimens; and eccentric growth increments on the external opercular surface. The type species, C. johnsoni new species, is described from latest Lochkovian pesavis Zone), early Pragian (suleatus Zone) and late Pragian (pireneae Zone) strata of the Garra Formation, Wellington, NSW. C. whitehollsei new ...