Paleoclimate time series: New alignment and compositing techniques, a 5.3-Myr benthic d18O stack, and analysis of Pliocene-Plesitocene climate transitions
Lorraine Lisiecki, Brown University, 2005
Committee: Prof. Timothy Herbert (advisor), Prof. Warren Prell, Prof. Thompson Webb, Prof. Karen Fischer, Prof. Maureen Raymo (Boston University)
Paleoclimate research has recently produced an explosion of new paleoclimate time series, but fully utilizing the acquired data requires coordinated analysis of globally distributed records. To this end, I developed a new automated graphic correlation technique, which uses dynamic programming to find the globally optimal alignment of two paleoclimate time series while constraining the records' relative accumulation rates. I further adapted the algorithm to automate the generation composite depth sections for marine sediments cores, and I characterized patterns of core deformation. I also aligned 57 globally distributed benthic d18O records to create a 5.3-Myr d18O stack, which describes Pliocene-Pleistocene ice volume and deep ocean temperature change. The stack and its orbitally tuned age model constrained by the sedimentation rates of 57 sites provide the paleoclimate community with important stratigraphic tools to aid in the comparison of widely distributed marine climate records. Finally, I analyzed the d18O stack in terms of glacial-cycle shape and response to orbital forcing to describe linear and nonlinear responses and to characterize climate transitions over the long-term cooling of the last 5.3 Myr. The results suggest an important climate transition at ~1.4 Ma.
Introduction. Why this research is important. Summary of results.
Lisiecki, L. E., and P. A. Lisiecki (2002), Application of dynamic programming to the correlation of paleoclimate records, Paleoceanography, 17(D4), 1049, doi:10.1029/2001PA000733. View PDF
Lisiecki, L. E., and T. D. Herbert (in press), Automated composite depth scale construction and estimates of sediment core extension, Paleoceanography. View Preprint
Lisiecki, L. E., and M. E. Raymo (2005), A Pliocene-Pleistocene stack of 57 globally distributed benthic d18O records, Paleoceanography, 20, PA1003, doi:10.1029/2004PA001071. View PDF
Most content found in: Lisiecki, L. E., and M. E. Raymo (2007), Plio-Pleistocene climate evolution: Trends and transitions in glacial cycle dynamics, Quaternary Science Reviews, 26, 56-69. View PDF
Appendices (Orbital forcing and d18O)