Project

Back to overview

CenoClump: Cenozoic ocean temperature reconstruction based on clumped isotopes

Applicant Meckler Anna Nele
Number 139701
Funding scheme Marie Heim-Voegtlin grants
Research institution Geologisches Institut ETH Zürich
Institution of higher education ETH Zurich - ETHZ
Main discipline Geology
Start/End 01.02.2012 - 30.06.2014
Approved amount 198'612.00
Show all

All Disciplines (3)

Discipline
Geology
Oceanography
Geochemistry

Keywords (5)

Cenozoic; foraminifera; temperature; paleoceanography; clumped isotopes

Lay Summary (English)

Lead
Lay summary

In this project, we are applying a new tool (“proxy") to reconstruct changes in ocean temperatures through the Cenozoic time period (the last 65 Million years). Within the Cenozoic, the earth has experienced large climatic changes, ranging from global warmth around 50 Million years ago to the ice ages of the more recent times. However, our current knowledge of Cenozoic climate relies on proxies that are ambiguous. The most commonly used climate proxy is the isotopic composition (δ18O) of shells from marine organisms. Their δ18O value is influenced by the temperature at which the shells are formed, which allows reconstructing ocean temperature. However, it is equally influenced by the global amount of ice stored on land, affecting the oxygen isotopic composition of seawater. At present, we can therefore not discern which aspects of the δ18O record are caused by changes in ocean temperature and which reflect changes in global ice volume. Other, independent approaches to reconstruct ocean temperatures have been applied in the past, but are all burdened with major uncertainties. Here we apply a novel tool for temperature reconstruction, called clumped isotope thermometry, to this longstanding question in paleoclimate.  The clumped isotope method determines the ordering of oxygen and carbon isotopes in carbonate, and can be applied to the same shells used for δ18O measurements. As the approach is thermodynamically based, it avoids many of the assumptions necessary for other methods. With this method, we will be able to derive both changes in ocean temperature and (in combination with δ18O) global ice volume. We expect to infer the long-term trends in ocean temperature and ice volume through the Cenozoic, as well as the contribution of both environmental parameters to some of the more rapid shifts observed in the δ18O record. The results will improve our understanding of the global climate system and it’s response to past changes in boundary conditions.


Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Long-term performance of the Kiel carbonate device with a new correction scheme for clumped isotope measurements
Meckler Anna Nele, Ziegler Martin, Millán M. Isabel, Breitenbach Sebastian F.M., Bernasconi Stefano M. (2014), Long-term performance of the Kiel carbonate device with a new correction scheme for clumped isotope measurements, in Rapid Communications in Mass Spectrometry, 28, 1705-1715.

Collaboration

Group / person Country
Types of collaboration
Prof. Aradhna Tripati, UCLA United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
Dr. Phil Sexton, The Open University, Milton Keynes Great Britain and Northern Ireland (Europe)
- in-depth/constructive exchanges on approaches, methods or results

Associated projects

Number Title Start Funding scheme
134987 Multidisciplinary study Of Continental/ocean Climate dynamics using High-resolution records from the eastern mediterraneAn (MOCCHA): Part 2 01.04.2011 Project funding
147139 Swiss participation in the International Ocean Discovery Program (IODP) through membership in the European Consortium for Ocean Research Drilling (ECORD) 01.01.2014 Research Infrastructure

Abstract

Cenozoic climate is characterized by a long-term cooling trend from the warm Early Eocene to the colder, but highly variable climate characterizing the Pleistocene glacial-interglacial cycles. This trend occurred both gradual and stepwise, and is best characterized by a global stack of benthic oxygen isotope (d18O) records. However, a yet unresolved question is the extent to which the d18O signal reflects changes in ocean temperatures or changes in global ice volume. Here we propose to apply the new carbonate clumped isotope temperature proxy to reconstruct deep-sea temperatures through the Cenozoic, in order to separate out the responses of different components of the climate system. Other available temperature proxies are either not applicable to the deep sea or prone to artifacts from changing ocean chemistry. The proposed study will therefore both contribute to a better understanding of existing temperature proxies and yield important new information about the global climate system.
-