USING IMAGE ANALYSIS AND XRF TO CONSTRAIN ORBITAL FORCING AND CLIMATE IN THE MEDITERRANEAN BASIN OVER THE LAST 500,000 YEARS

The Mediterranean Sea provides a critical reservoir for uniquely capturing the planet’s orbital climate signal due to its location and near-closed basin properties that are more sensitive to more localized climate variations than the open ocean. This study focuses on timeseries analysis of the classic and well-characterized Mediterranean sediment core RC9-181PC (1, 2) as well as ODP site 964 (3, 4) and NESSC core 64PE406E1 (5) to quantitatively explore the relationship between sapropels and the orbital climate cycles that are proposed to have produced them. The time covered by these cores spans the near present to nearly 600 Kyr. Data include grayscale and reflectance profiles in RC9-181PC and ODP site 964, new XRF chemistry on RC9-181PC and published XRF chemistry on NESSC 64PE406E1, using published age models for each core. Preliminary analysis reveals the expected strong climatic precession- and eccentricity-pacing as well as at least some pacing by obliquity, as has been previously modeled [e.g., (6)]. To our knowledge, this study will provide the first quantitative frequency analysis of the Milankovitch pacing of this classic and important paleoclimatological archive and challenges our understanding of the climate system to local orbital forcing.

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