Details of Award
NERC Reference : NE/X002438/1
Improving seawater chemistry reconstructions using the biogenic silica archive
Grant Award
- Principal Investigator:
- Dr S E Modestou, Northumbria University, Fac of Engineering and Environment
- Grant held at:
- Northumbria University, Fac of Engineering and Environment
- Science Area:
- Marine
- Overall Classification:
- Unknown
- ENRIs:
- Global Change
- Science Topics:
- Deep ocean circulation
- Ocean drilling
- Palaeoclimate observation
- Climate & Climate Change
- Surface ocean circulation
- Ocean drilling
- Palaeoenvironments
- Ocean drilling
- Quaternary Science
- Sediment/Sedimentary Processes
- Ocean drilling
- Ocean Circulation
- Abstract:
- One of the primary goals of Exp. 395 is to examine the connection between changes in oceanic circulation in the North Atlantic and changes in bathymetry due to magmatic pulsing. Using the additional sediment collected during Exp. 395C, I will target two questions which support this overarching cruise goal. The first question is, can we quantitatively understand post-depositional changes in the oxygen isotope composition of biogenic silica? Biogenic silica is an important component of the sedimentary record. Over 50% of global primary production is due to diatoms, while high latitude environments preserve biogenic silica far better than the other popular palaeo-archive (carbonate). However, difficult to quantify offsets have been observed in diatoms, making it difficult understanding how much of the original chemical signal of the ocean is preserved in this fossil. Consequently, we need to improve our understanding before we can use this archive with confidence. The aim of this objective is to accurately identify the amount of diagenesis affecting biogenic silica at specific depths in the sedimentary sequence, enabling more confident application of diatom and sponge spicule fossils for climate reconstructions. I will use a novel combination of advanced analyses (carbonate clumped isotope analysis and triple oxygen isotope analysis) on both carbonate and biogenic silica fossils from the same samples of core material to tackle this problem. The second question is, what processes are related to the patterns of initial sedimentation observed at the Exp. 395C sites? And how, if at all, are these processes related to changes in circulation? Exp. 395 (scheduled for 2023) and Exp. 395C both have the overarching major cruise objective of understanding whether magmatic pulsing of the Iceland plume has caused changes in deep oceanic circulation. Circulation in this region is directly related to deep water formation in the North Atlantic, which has a major influence on global climate. The sediments initially deposited on new oceanic plate in the region, regardless of age, seem to be incredibly similar (as observed from initial core photos from Exp. 395C). These initial sediments are also strikingly different from overlying sediments which are more similar to those normally found across the North Atlantic. Deciphering the causes and mechanisms leading to the different patterns observed will allow us to understand what was happening in the region during the onset of sedimentation and determine if these initial sediments are suitable for constraining changes in circulation.
- NERC Reference:
- NE/X002438/1
- Grant Stage:
- Awaiting Event/Action
- Scheme:
- Directed (RP) - NR1
- Grant Status:
- Active
- Programme:
- UK IODP Phase4
This grant award has a total value of £59,696
FDAB - Financial Details (Award breakdown by headings)
| DI - Other Costs | Indirect - Indirect Costs | DA - Investigators | DA - Estate Costs | DI - T&S |
|---|---|---|---|---|
| £19,880 | £11,667 | £21,874 | £604 | £5,671 |
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