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Sediment Trap Time Series of GDGT and alkenone flux in the Gulf of Mexico

Metadata Updated: October 29, 2023

The tetraether index of C86 (TEX86) and alkenone unsaturation index (Uk37Õ) molecular biomarker proxies have been broadly applied in down-core marine sediments to reconstruct past sea surface temperature (SST). Although both TEX86 and Uk37 have been interpreted as proxies for mean annual SST throughout the global ocean, regional studies of glycerol dibiphytanyl glycerol tetraethers (GDGT)s and alkenones in sinking particulate matter (SPM) are required to understand the influence of seasonality, depth distribution and diagenesis on downcore variability. USGS scientists measured GDGT and alkenone flux, as well as the TEX86 and Uk37Õ indices in a 4-year sediment trap time series (2010-2014) in the northern Gulf of Mexico (nGoM), with weekly-to-monthly resolution, and compared these data with core-top sediments at the same location. GDGT and alkenone fluxes do not show a consistent seasonal cycle; however, the largest flux peaks for both occurs in winter. Uk37 co-varies with SST over the 4-year sampling interval, but the U-SST relationship in this dataset implies a smaller slope or non-linearity at high temperatures when compared with existing calibrations. Furthermore, the flux-weighted Uk37 value from sinking particles is significantly lower than that of underlying core-top sediments, suggesting preferential diagenetic loss of the tri-unsaturated alkenone in sediments. TEX86 does not co-vary with SST, suggesting production in the subsurface ocean. The flux-weighted mean TEX86 matches that of core-top sediments, suggesting that sedimentary TEX86 in the Gulf of Mexico reflects local autochthonous production. We explore these potential sources of uncertainty in both proxies in the GoM, but demonstrate that they show nearly identical trends in 20th century SST, despite these factors.

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Dates

Metadata Created Date June 1, 2023
Metadata Updated Date October 29, 2023

Metadata Source

Harvested from DOI EDI

Additional Metadata

Resource Type Dataset
Metadata Created Date June 1, 2023
Metadata Updated Date October 29, 2023
Publisher U.S. Geological Survey
Maintainer
@Id http://datainventory.doi.gov/id/dataset/1a63ee3ee7e66832a80a288f98195d9d
Identifier USGS:77befd4c-d6ea-4224-9aec-7d7a9ae3d26c
Data Last Modified 20201013
Category geospatial
Public Access Level public
Bureau Code 010:12
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Metadata Catalog ID https://datainventory.doi.gov/data.json
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id 2488d94d-5ae3-476c-966f-540743439167
Harvest Source Id 52bfcc16-6e15-478f-809a-b1bc76f1aeda
Harvest Source Title DOI EDI
Metadata Type geospatial
Old Spatial 91.0,27.0,90.0,28.0
Publisher Hierarchy White House > U.S. Department of the Interior > U.S. Geological Survey
Source Datajson Identifier True
Source Hash 86eb4a395e8e37e30b2a5fc9f889506d98493282757ccebea6b3cb6e1bdee4a7
Source Schema Version 1.1
Spatial {"type": "Polygon", "coordinates": 91.0, 27.0, 91.0, 28.0, 90.0, 28.0, 90.0, 27.0, 91.0, 27.0}

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