Project Details
Projekt
Inorganic geochemistry of Pliocene-Pleistocene sediments from the Bering Sea (IODP Expedition 323) - Studying feedbacks of productivity, nutrient availability, and redox conditions in the northernmost Pacific
Applicant
Professor Dr. Christian März
Subject Area
Palaeontology
Term
from 2010 to 2012
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 180267101
In 2009, Expedition 323 of the Integrated Ocean Drilling Program (IODP) recovered the first continuous sediment cores from the Bering Sea extending back 5 Million years. The unique IODP core material has considerable potential to unlock the environmental and climatic history of the Bering Sea. The Bering Sea is a large, yet poorly explored natural laboratory to study the development of climate-relevant biogeochemical element cycles in a high-productivity semi-restricted upwelling system on glacial-interglacial time scales. Moreover, the Bering Sea is of global relevance (a) due to its potential for atmospheric CO2 sequentation and its burial in the sea floor as organic matter over long time scales, and (b) due to the export of low-oxygen high-nutrient glacial water to the North Pacific and related effects on productivity, stratification, and carbon burial in the world´s largest ocean basin. Our main goal is to decipher biogeochemical dynamics and coupling that have hardly been studied both in the Bering Sea and globally so far, but may be of importance for atmosphere- ocean CO2 exchange and thus for climate dynamics on glacial-interglacial time scales: The feedbacks between primary productivity, middle and deep redox conditions, and nutrient recycling from the sediment. We will focus on sediments from two sites representative for the environmental regimes of the Bering Sea, namely open marine Site U1341, and Site U1343 at the continental slope. We will construct inorganic geochemical sediment records (Ba, Fe, P, redox-sensitive trace metals) to trace nutrient, productivity and ocean redox variations over the past 2-5 million years, but also to quantify diagenetic processes that affected primary environmental signals. To evaluate the effects of Pliocene- Pleistocene biogeochemical dynamics and interactions on a more global scale, we will compare our records from the Bering Sea to published data and interpretations from the North Pacific (e.g. ODP Leg 145). In summary, our main research topics are: 1. The development of bioproductivity and related carbon burial.2. The dynamics and coupling of Fe and P under variable redox conditions.3. The effects of early diagenesis on primary geochemical sediment signals.4. The relation between Pliocene-Pleistocene geochemical conditions in the Bering Sea and the North Pacific.
DFG Programme
Infrastructure Priority Programmes
International Connection
United Kingdom
