Calibration of speleothem delta O-18 with instrumental climate records from Turkey


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Jex C. N., Baker A., Fairchild I. J., Eastwood W. J., Leng M. J., Sloane H. J., ...Daha Fazla

GLOBAL AND PLANETARY CHANGE, cilt.71, sa.3-4, ss.207-217, 2010 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 71 Sayı: 3-4
  • Basım Tarihi: 2010
  • Doi Numarası: 10.1016/j.gloplacha.2009.08.004
  • Dergi Adı: GLOBAL AND PLANETARY CHANGE
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.207-217
  • Anahtar Kelimeler: speleothem, climate calibration, stable isotopes, Turkey, STABLE-ISOTOPE VARIATIONS, GROWTH-RATE, PRECIPITATION, EQUILIBRIUM, PRESSURE, LAMINAE, TRENDS, DRY
  • Ankara Üniversitesi Adresli: Evet

Özet

Stalagmite records of oxygen (delta O-18) isotopes, sampled at sub-annual resolution by micro-mill techniques are correlated with climate parameters over the instrumental period (1961 to 2005 AD). The strongest correlations were found between delta O-18 and total amount of late autumn-winter precipitation (October to January) smoothed by 6 yr, with marginally weaker correlations between the total amount of late autumn-spring precipitation (ONDJF and ONDJFMA) smoothed over the same time period. Two smoothing options were chosen to account for variability in mixing and residence times of stored water in the karst aquifer prior to entering the cave: (1) An average of the last 6 yr of precipitation which yielded a product correlation of -0.71 for the months ONDJ; and (2) a mixing model of 10% short term/event water (<1 yr) and 90% water of a longer residence time in the karst aquifer (2 to 6 yr) which gave a product correlation of -0.72 for the months ONDJ. Precipitation is calibrated over the instrumental period (1961 to 2004 AD) based on linear regression of delta O-18 with observed precipitation for the months ONDJ, ONDJF and ONDJFMA using both smoothing methods. An uncertainty of +/-31 mm (2 standard errors on the linear regression) is applied to the calibrations. This is the first speleothem calibration of its kind in Turkey. (C) 2009 Elsevier B.V. All rights reserved.