Effect of intraband variability on stable isotope and density time series obtained from banded corals

[摘要] Density, 𝛿18O and 𝛿13C were measured along two tracks, one close to the central growth axis and the other, ∼20° off the axis, in a coral (Porites lutea) collected from the Stanley Reef, Central Great Barrier Reef, Australia. The 𝛿18O variations in the coral are well correlated with sea surface temperature changes. The common variances between the two tracks were about 60% in the 𝛿18O, 𝛿13C and the skeletal density variations. Part of the noise (40%) could be due to the difficulty of sampling exactly time contemporaneous parts of each band along the two tracks and part of it could be due to genuine intraband variability. In spite of the intraband variability, the time series obtained from the two tracks are similar, indicating that the dominant causative factor for the isotopic variations is external, i.e., the environmental conditions that prevail during the growth of the coral; density band formation does not appear to be directly controlled by the sea surface temperature.

[学科分类] 天文学(综合)

[关键词] Carbon isotope;oxygen isotope;SST;climate;coral;Great Barrier Reef.