Drilling Transects to Explore the Interconnected Earth
Abstract
Since its inception over 50 years ago scientific ocean drilling has demonstrated the value of coring along transects to investigate a diverse range of Earth system processes. However, systematic sampling of both the sediment and the underlying crust in a specific region has rarely been undertaken, and the few transects accomplished span relatively short intervals of Earth history. The `Transect Drilling During Transits' workshop (College Station, Texas, Nov 2013) was convened to explore opportunities for multidisciplinary drilling transects exploiting drill ship transits. A key outcome was the development of the South Atlantic Transect (SAT; IODP Exp 390/393), which will recover complete sediment sections and the upper ~200 m of oceanic crust along a slow/intermediate spreading rate Mid-Atlantic Ridge crustal flow-line from 7 to 61 Ma at ~31°S. The Expeditions' transect strategy was designed to simultaneously advance objectives across all four themes of the current IODP Science Plan.
Despite previous drilling efforts major gaps remain in our observations of the evolving Earth system, such as cores of ocean crust of different ages formed at contrasting spreading rates, virtually unexplored biogeographic microbial provinces, and high resolution records of key times in Earth's climate, ocean chemistry or magnetic field history. The overarching goal of the 2050 Science Framework (2050SF) is to understand the interconnected Earth. Transects of drill holes that sample sediments and the uppermost oceanic crust, such as the SAT, can illuminate how interconnected processes evolved over Earth's history and their responses to changes in external drivers such as atmospheric CO2concentrations, oceanic gateways or major ocean currents. The 2050SF's multi-decadal outlook provides an opportunity to develop transect strategies, which typically require multiple expeditions, that would make valuable contributions to multiple 2050SF Strategic Objectives (SO) and Flagship Initiatives (FI). For example, transects that sample tens of millions of years of ocean crust along crustal flow lines can provide important information on the duration of hydrothermal exchange required to quantify the role the oceanic life cycle of tectonic plates (SO2) in global cycles of energy and matter (SO6) and explore the limits of life (FI5).- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMOS026..09C
- Keywords:
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- 3344 Paleoclimatology;
- ATMOSPHERIC PROCESSES;
- 0448 Geomicrobiology;
- BIOGEOSCIENCES;
- 8137 Hotspots;
- large igneous provinces;
- and flood basalt volcanism;
- TECTONOPHYSICS;
- 8155 Plate motions: general;
- TECTONOPHYSICS