Marine Climate Archives

Reconstructing the ocean and climate processes of the past will enable us to make well-founded statements about the future. Continuous and reliable instrumental measurement series, even of simple parameters such as air and water temperatures, exist for the last 150 years at most. This is far too short to provide information about long-term climate developments, because these take place over centuries, millennia or even millions of years. In order to obtain data from the past, climate researchers take samples from various natural climate archives, from which the environmental conditions of past times, such as temperature, fluctuations in sea level or the composition of the air and ocean, can be derived.

What are natural climate archives?

Depending on the type of sample used, information on different climate elements can be obtained, with tree rings and corals providing data from relatively short periods of time, but at a high temporal resolution. Ice cores from ice sheets or glaciers can reflect annual differences up to 1 billion years ago. Marine sediments, on the other hand, show a very coarse temporal resolution, but contain climate data reaching far back into the Earth's historical past.

At GEOMAR, both sediment cores and coral samples are studied. Oceanic environmental conditions are not stored directly in sediments or corals, but have to be determined indirectly via so-called proxies.

The History of the Pacific

The expedition SO264 Emperor with the German research vessel SONNE aimed to reconstruct the climatic and oceanographic conditions of the North Pacific in the past. For this purpose, the team of 38 researchers from eleven nations, led by Prof. Dr. Dirk Nürnberg from GEOMAR's Paleo-Oceanography research unit, collected sediment samples for the first time continuously in largely unexplored offshore regions along the line of the Emperor volcanic chain.

Research News: Marine Climate Archives

Research vessel MA­RIA S. ME­RI­AN

Hot on the trail of the causes of rapid ice sheet instabilities in climate history

Heat accumulation in the deeper subpolar North Atlantic triggers Heinrich events

Air bubbles under water

Weaker ocean cir­cu­la­tion led to more car­bon stor­age in the deep sea

New study on oxy­gen levels in deep ocean wa­ters dur­ing the last ice age

Drill cores from the MARUM-Mebo200 are recovered on deck of the RV METEOR. Photo: Christian Rohleder.

In the deep sea, the last ice age is not yet over

Gas hydrate deposits in the Black Sea react to post-glacial climate changes

Preparation of samples for isotope investigation in the GEOMAR laboratories. Photo: Jan Steffen, GEOMAR.

How the sea level influences the global carbon cycle

Isotope measurements in Kiel provide new insights into carbonate deposits on the sea floor

A man and a woman standing a ship's bulwark handle a CTD rosette. Photo: Martin Visbeck

A stable ocean circulation in a changing North Atlantic Ocean

New study shows surprising contrast between ocean properties and currents