21
Climate and the Evolution of the Ocean: The
Paleoceanographic Data
Thibaut Caley, Natalia Vázquez Riveiros, Laurent Labeyrie, Elsa Cortijo,
and Jean-Claude Duplessy
Introduction: The Development of Tools
and Concepts
The idea of reconstructing the history of oceans and climates
in the past using marine sediment cores arrived quite late
after the beginnings of oceanography. It was initiated in the
twentieth century, well after the first attempts to measure
variations in seawater temperature down the water column,
which date back to the eighteenth century with the great
circumnavigation expeditions. Land geologists were the first
to propose paleoceanographic reconstructions from exposed
marine series, limiting the collected information to former
coastal waters. The first reconstructions of past seawater
temperatures were made possible by the piston corer
developed by the Swedish oceanographer Kullenberg, capable of collecting continuous sedimentary deposits without
layer disruption. Geologists were therefore able to collect
uninterrupted sedimentary series, sometimes over 20 m in
length, for laboratory analysis, and thus study long records
of the environmental conditions from the time the sediments
were deposited. With this type of corer, the Swedish
expedition of 1947–1948 collected over 300 different cores
from various deep ocean basins that became the basis of the
first studies on the geological history of the oceans. In parallel, during the 1950s, Maurice Ewing, the founder of the
Lamont-Doherty Geological Observatory (USA), and one of
the developers of seismic sediment mapping of the ocean
floor, initiated the first systematic collection of marine sediment cores. The first descriptions of the main sedimentary
systems, changes in fossil faunas and the timeframe for the
first biostratigraphic age scales were proposed based on
these cores. One of the main results of these studies was the
continuous reconstruction of the alternating warm and cold
phases that took place during the Pleistocene.
Unquestionably, the honor for the initiation of quantitative
paleoceanography belongs to Cesare Emiliani. After the discovery of isotopic fractionation and the development of an
accurate method to measure isotopic ratios, Harold Urey and
his group in Chicago refined the use of the isotopic ratio
18
O/
16
O in fossil carbonates as a paleothermometer. They
realized that the
18
O/
16
O ratio of foraminiferal shells and other
carbonates depended on two variables: the temperature and the
18
O/
16
O ratio of the water where the carbonate was formed.
Changes in water temperature are reflected in variations in the
isotopic fractionation between the carbonate and the water
during the formation of the shell: for water with a given isotopic
composition, the higher the temperature, the lower the
18
O/
16
O
ratio (Epstein et al. 1951, 1953). Emiliani (1955) applied this
tool to foraminifera shells sampled along a sediment core from
the Caribbean Sea to propose the first reconstruction of the
variations in sea surface temperature (SST) over the past
400 ka (Fig. 21.1). He also established the major methodological guidelines for this type of study: use of continuous
records, precise dating, and interpretation of parameters
quantitatively linked to key variables of the climate system.
To extract a temperature signal from the
18 O/
16 O ratio of
planktonic foraminifera, Emiliani had to constrain the
changes in the isotopic composition of the ocean water in
which the foraminifera developed. The
18 O/
16 O ratio of
Thibaut Caley, Natalia Vázquez Riveiros and Laurent Labeyrie—
These authors have contributed equally to this chapter.
T. Caley (&)
EPOC, UMR 5805, CNRS, University of Bordeaux, Pessac,
France
e-mail: thibaut.caley@u-bordeaux.fr
N. V. Riveiros Á L. Labeyrie Á E. Cortijo Á J.-C. Duplessy
Laboratoire des Sciences du Climat et de l’Environnement,
LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay,
91190 Gif-sur-Yvette, France
N. V. Riveiros
Institut Français de Recherche pour l’Exploitation de la Mer
(Ifremer), Unité de Geosciences Marines, Pointe du Diable,
29280 Plouzané, France
L. Labeyrie
LGO Université Bretagne Sud, 56000 Vannes, France
© Springer Nature Switzerland AG 2021
G. Ramstein et al. (eds.), Paleoclimatology, Frontiers in Earth Sciences,
https://doi.org/10.1007/978-3-030-24982-3_21
225
Climate and the Evolution of the Ocean: The
Paleoceanographic Data
Thibaut Caley, Natalia Vázquez Riveiros, Laurent Labeyrie, Elsa Cortijo,
and Jean-Claude Duplessy
Introduction: The Development of Tools
and Concepts
The idea of reconstructing the history of oceans and climates
in the past using marine sediment cores arrived quite late
after the beginnings of oceanography. It was initiated in the
twentieth century, well after the first attempts to measure
variations in seawater temperature down the water column,
which date back to the eighteenth century with the great
circumnavigation expeditions. Land geologists were the first
to propose paleoceanographic reconstructions from exposed
marine series, limiting the collected information to former
coastal waters. The first reconstructions of past seawater
temperatures were made possible by the piston corer
developed by the Swedish oceanographer Kullenberg, capable of collecting continuous sedimentary deposits without
layer disruption. Geologists were therefore able to collect
uninterrupted sedimentary series, sometimes over 20 m in
length, for laboratory analysis, and thus study long records
of the environmental conditions from the time the sediments
were deposited. With this type of corer, the Swedish
expedition of 1947–1948 collected over 300 different cores
from various deep ocean basins that became the basis of the
first studies on the geological history of the oceans. In parallel, during the 1950s, Maurice Ewing, the founder of the
Lamont-Doherty Geological Observatory (USA), and one of
the developers of seismic sediment mapping of the ocean
floor, initiated the first systematic collection of marine sediment cores. The first descriptions of the main sedimentary
systems, changes in fossil faunas and the timeframe for the
first biostratigraphic age scales were proposed based on
these cores. One of the main results of these studies was the
continuous reconstruction of the alternating warm and cold
phases that took place during the Pleistocene.
Unquestionably, the honor for the initiation of quantitative
paleoceanography belongs to Cesare Emiliani. After the discovery of isotopic fractionation and the development of an
accurate method to measure isotopic ratios, Harold Urey and
his group in Chicago refined the use of the isotopic ratio
18
O/
16
O in fossil carbonates as a paleothermometer. They
realized that the
18
O/
16
O ratio of foraminiferal shells and other
carbonates depended on two variables: the temperature and the
18
O/
16
O ratio of the water where the carbonate was formed.
Changes in water temperature are reflected in variations in the
isotopic fractionation between the carbonate and the water
during the formation of the shell: for water with a given isotopic
composition, the higher the temperature, the lower the
18
O/
16
O
ratio (Epstein et al. 1951, 1953). Emiliani (1955) applied this
tool to foraminifera shells sampled along a sediment core from
the Caribbean Sea to propose the first reconstruction of the
variations in sea surface temperature (SST) over the past
400 ka (Fig. 21.1). He also established the major methodological guidelines for this type of study: use of continuous
records, precise dating, and interpretation of parameters
quantitatively linked to key variables of the climate system.
To extract a temperature signal from the
18 O/
16 O ratio of
planktonic foraminifera, Emiliani had to constrain the
changes in the isotopic composition of the ocean water in
which the foraminifera developed. The
18 O/
16 O ratio of
Thibaut Caley, Natalia Vázquez Riveiros and Laurent Labeyrie—
These authors have contributed equally to this chapter.
T. Caley (&)
EPOC, UMR 5805, CNRS, University of Bordeaux, Pessac,
France
e-mail: thibaut.caley@u-bordeaux.fr
N. V. Riveiros Á L. Labeyrie Á E. Cortijo Á J.-C. Duplessy
Laboratoire des Sciences du Climat et de l’Environnement,
LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay,
91190 Gif-sur-Yvette, France
N. V. Riveiros
Institut Français de Recherche pour l’Exploitation de la Mer
(Ifremer), Unité de Geosciences Marines, Pointe du Diable,
29280 Plouzané, France
L. Labeyrie
LGO Université Bretagne Sud, 56000 Vannes, France
© Springer Nature Switzerland AG 2021
G. Ramstein et al. (eds.), Paleoclimatology, Frontiers in Earth Sciences,
https://doi.org/10.1007/978-3-030-24982-3_21
225