Theme 5: Earth history and global change

Michael Sarnthein, Wolfgang Kuhnt (both: University of Kiel)

The most recent major climate change was associated with fundamental changes in ice volume, ocean circulation, carbon inventories, and land vegetation subsequent to the Last Glacial Maximum (LGM) 19,000 – 10,000 y BP. These transitions comprised in part conflicting trends registered on land and in the ocean. Independent and adequate high-resolution age control may help to approach the open questions of synchrony and/or fine-scale phase relationships, crucial to improve our understanding of the complex processes and causal chains that were at play during this event of major climate change. To discuss these exciting questions we invite all kind of contributions that display time series of climate reconstructions including both empiric data and model simulations.

Thomas Felis (MARUM, Bremen), Miriam Pfeiffer (RWTH Aachen University), Jens Zinke (FU Berlin)

Shallow-water coral archives provide precisely-dated annually to monthly-resolved reconstructions of marine climate and environmental change from across the global tropics to subtropics. They are a key archive to constrain past seasonal, interannual and decadal variability – the time scales most relevant to human societies – beyond the start of systematic reef monitoring programs and instrumental observations of climate. Coral reconstructions extending back for centuries provide a link between the observational period and lower-resolution sediment archives. This is of high relevance for comparisons of proxy data with model simulations of reef ecosystem dynamics and global climate. Well-preserved fossil corals provide high-resolution snapshots for time intervals of the Holocene, the last glacial-interglacial cycles, the Miocene and the Pliocene.
Coral paleoclimatology provides an opportunity for collaborations among paleoclimatologists, marine geologists, coral reef ecologists, carbonate geochemists, experts in biomineralization, carbonate diagenesis and U-series dating, climate modellers, climate dynamicists, and climate statisticians, in order to provide robust and innovative paleoclimate and environmental reconstructions and interpretations. Recent collaborative efforts include expeditions of the International Ocean Discovery Program (IODP) and synthesis works of the Past Global Changes (PAGES) Ocean 2k initiative.
On the occasion of the German Science Year 2016*17 - Seas and Oceans - we like to invite the international coral paleoclimate community and researchers from the related disciplines to present their latest research at the GeoBremen 2017, and we strongly encourage PhD students and early career scientists to participate. The aim of this session is to present and discuss latest research on past marine climate and environmental change at society-relevant timescales (seasonal, interannual, decadal), in order to understand the long-term context and impacts of future changes in the tropical to subtropical oceans, reef ecosystems, and adjacent continents. We welcome a wide range of contributions, in particular on (1) the development and calibration of new proxies and dating methods, (2) climatic, environmental and ecological reconstructions from high resolution proxy time series, (3) the use of such proxies in model-proxy data comparisons, and (4) implications for the future of coral reefs in times of anthropogenic-induced climatic and environmental change.
The session will be accompanied by a 1-day workshop aiming at the exchange of ideas, the identification of key scientific priorities for the coming decades, and the promotion of future joint research activities.

Guido Meinhold (University of Göttingen), A. M. Celâl Şengör (Istanbul Technical University, TR)

Palaeogeography is the reconstruction of Earth's history by presenting former conditions of physical geography in cartographic depictions. Different rock types and structures are studied in detail in regard to age, composition and tectonic setting either for a specific region or the entire globe in time slices with a view to reconstructing former physical geographical environments. The topography of land masses, the bathymetry of former seas and the circulation of oceanic waters, former wind patterns and distribution of organisms are also often included in such reconstructions. Palaeogeographic reorganisations of major geographical features have a strong influence on, for example, the climate, the evolution of ecosystems, basin development, mountain formation, and resource geology. Understanding the current changes in the physical geography of our globe, such as global warming and the rates involved, is only possible if we know its history. A better understanding of Earth's palaeogeography through geologic time is therefore highly desirable. Contributions on any topic relevant to palaeogeography are welcome, with special emphasis on presenting new methodologies and developments.