Subtask: Hindcast of NGOM Holocene Climate and Climate Variability
Subtask Leader: Richard Poore - USGS Florida Integrated Science Center, St. Petersburg, Florida
Subtask Aim
Information on climate, climate variability, and sea-level change during the Holocene are needed to help establish the forces controlling the evolution of northern Gulf of Mexico coastal systems. Evaluation and synthesis of existing data are needed to identify gaps in knowledge and to identify the areas and types of new information that are needed. Accordingly, Subtask 2.3 will characterize and synthesize climatic changes in the coastal region of the northern Gulf of Mexico over the last ~10,000 years. Climatic variables that will be studied using stable isotopic, geochemical tracers, and faunal records will include storm frequency-severity, sea surface temperature, and aridity - humidity. Emphasis will be on the last 6,000 years, with a particular focus on selected intervals representing end-member variations in climate, and on climate variability such as that represented by the Little Ice Age, the Medieval Warm Period, and the mid-Holocene warm interval. The objective of this subtask is to reconstruct climate and climate variability of the NGOM coast, including changes in the magnitude and frequency of severe storms; sea-level history will be included in this effort.
The initial focus will be on reviewing, compiling and synthesizing existing field observations relevant to NGOM Holocene climate and sea-level history, in part to identify gaps in knowledge, and to select locations and time-intervals for additional study. Information on sediment distribution and geometry will be developed from seismic surveys on the continental shelf to be conducted within Subtasks 2.1 and 2.2. Sediment coring will be done to a "ground truth" and date the features identified in the seismic surveys.
Information on climate and climate variability will be developed through analyses of marine and continental sediments. Existing records and companion studies from areas adjacent to the NGOM coast will be used to place local records into regional and hemispheric context. As the study progresses, a series of onshore-offshore sampling transects will be established and surveyed, in order to fill in gaps and develop detailed information for selected regions and time periods. Sediment coring to determine the distribution of storm deposits in time and space will be conducted in coordination with climate history work to investigate links between climate state and variability and the frequency and magnitude of storms. The final stages of the effort will involve developing broad-scale landscape reconstructions for the NGOM that depict distribution of major environments at selected time intervals.
Seismic surveys will be used to guide sediment coring to"ground truth" and date subsurface units. Sites that appear to have potential for preserving detailed climate records will also be cored and analyzed to develop detailed local climate information.
Information on local climate and environmental conditions developed from cores taken during this study will be integrated with existing information and new studies in offshore areas to develop a regional climate and environmental history of the NGOM region. Review and evaluation of the published studies of the distribution of storm deposits in time and space and coring to obtain new records of storm deposits in the NGOM region will be carried out and compared with climate variability information to investigate the link between climate and the frequency and magnitude of major storms. The final stages of this subtask will be to participate in the development of broad-scale landscape reconstructions for the NGOM that depict distribution of major environments at selected time intervals.
Subtask Activities
The goal of this subtask is to reconstruct sea-level history, climate, and climate variability of the NGOM, including changes in magnitude and frequency of severe storms.
The specific objectives are to:
- Document climate and sea-level histories from NGOM marine and continental sediments at specific localities, and
- Synthesize these results into a regional summary of conditions during the Holocene as they impact the evolution of the NGOM coast.
Subtask Publications
Osterman, L.E., Kelley, W.S., and Ricardo, J.P., 2008, Benthic foraminiferal census data from Louisiana shelf cores, Gulf of Mexico: U.S. Geological Survey Open-File Report 2008-1348.
Osterman, L.E., Poore, R.Z., and Swarzenski, P.W., 2008, Gulf of Mexico dead zone - 1000-year record: U.S. Geological Survey Open-File Report 2008-1009, 2 p.
Osterman, L.E., Poore, R.Z., and Swarzenski, P.W., 2008, 1000 years of recurring natural and anthropogenic low-oxygen water on the Louisiana shelf, Gulf of Mexico [abstract #46], in 2008 Ocean Sciences meeting, March 2-7, 2008, Orlando, FL, American Society of Limnology and Oceanography.
Osterman, L.E., Poore, R.Z., and Swarzenski, P.W., 2008, 20th Century development and expansion of Louisiana shelf hypoxia, Gulf of Mexico [abstract and presentation], in Lavoie, D., and Rosen, B., eds., USGS Gulf Coast Science Conference and Florida Integrated Science Center Meeting: Proceedings with Abstracts, October 20-23, 2008, Orlando, FL: St. Petersburg, FL, U.S. Geological Survey Open-File Report 2008-1329, p. 73.
Osterman, L.E., Swarzenski, P.W., and Poore, R.Z., 2008, A 1000 year record of low-oxygen bottom water on the Louisiana shelf, Gulf of Mexico [abstract], in Lavoie, D., and Rosen, B., eds., USGS Gulf Coast Science Conference and Florida Integrated Science Center Meeting: Proceedings with Abstracts, October 20-23, 2008, Orlando, FL: St. Petersburg, FL, U.S. Geological Survey Open-File Report 2008-1329, online only.
Osterman, L.E., Twichell, D.C., and Poore, R.Z., 2008, Holocene evolution of Apalachicola Bay, Florida [abstract and poster], in Lavoie, D., and Rosen, B., eds., USGS Gulf Coast Science Conference and Florida Integrated Science Center Meeting: Proceedings with Abstracts, October 20-23, 2008, Orlando, FL: St. Petersburg, FL, U.S. Geological Survey Open-File Report 2008-1329, p. 74.
Poore, R.Z., DeLong, K., Tedesco, K., Osterman, L.E., Richie, J., and Quinn, T., 2008, Natural climate variability in northern Gulf of Mexico and adjacent Gulf Coast [abstract and poster], in Lavoie, D., and Rosen, B., eds., USGS Gulf Coast Science Conference and Florida Integrated Science Center Meeting: Proceedings with Abstracts, October 20-23, 2008, Orlando, FL: St. Petersburg, FL, U.S. Geological Survey Open-File Report 2008-1329, p. 76.
Poore, R.Z., and Richey, J.N., 2008, Northern Gulf of Mexico climate variability [abstract #50], in 2008 Ocean Sciences meeting, March 2-7, 2008, Orlando, FL, American Society of Limnology and Oceanography.
Poore, R. Z., 2008, Holocene Climate and Climate Variability of the Northern, Gulf of Mexico and Adjacent Northern Gulf Coast: A Review; The Open, Paleontology Journal, v. 1, p. 7-11
Osterman, L. E., Poore, R. Z., and Swarzenski, P. W., 1000 years of recurring natural and anthropogenic low-oxygen water on the Louisiana Shelf, Gulf of Mexico: Ocean Sciences Meeting – March 2008. Orlando, Florida
Osterman, L.E., Twichell, D.C., and Poore, R.Z., 2009, Holocene evolution of Apalachicola Bay: Geo-Marine Letters, v. 29, no. 6, p. 395-404.
Osterman, L.E., Poore, R.Z., Swarzenski, P.W., Senn, D., DiMarco, S., and Turner, R.E., 2009, The 20th century development and expansion of Louisiana shelf hypoxia, Gulf of Mexico: Geo-Marine Letters, v. 29, no. 6, p. 405-414.
Poore, R.Z., DeLong, K., Richey, J., and Quinn, T.M., 2009, Evidence of multidecadal climate variability and the Atlantic Multidecadal Oscillation from a Gulf of Mexico sea-surface temperature-proxy record: Geo-Marine Letters, v. 29, no. 6, p. 477-484.
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URL of this page is: http://ngom.usgs.gov/task2_3/index.html