Research Interests

My research involves a multi-proxy approach to abrupt climate change reconstruction for the last deglaciation (~25-10 ka) based on Gulf of Mexico (GOM) deep-sea sediments. Orca Basin, in the northern GOM exhibits high sedimentation rates (~45 cm/1000 yrs) and is ideally located to capture the melting history of the Laurentide Ice sheet (via Mississippi River) while recording regional GOM sea-surface temperature (SST) and sea-surface salinity (SSS) changes.

Projects

1) Generation of Ba/Ca and δ18Osw data, based on the planktic foraminifera, G. ruber (white and pink varieties, separately) from Orca Basin, to determine the timing and duration of Laurentide Ice Sheet melting episodes, and to assess changes in GOM SSS due to changes in meltwater input volume.

2) Reconstruction of high-resolution Mg/Ca-SST records based on G. ruber (white and pink) for the last 25 ka to assess whether changes in GOM SST coincide with abrupt climate events such as the Mystery Interval (17.5-14.5 ka), the Bolling-Allerod (14.7-13.0 ka) and the Younger Dryas (12.9-11.7 ka).

3) Analysis of redox sensitive trace metals in bulk sediment samples to determine the sediment oxygenation state of Orca Basin during the Last Glacial Maximum (LGM), deglaciation, and early Holocene (24-7 ka), and the origin of sedimentary redox condition changes.

4) Comparison of the sub-tropical and low-latitude model-derived vs. proxy record climate response to glacial meltwater routing (North Atlantic vs. GOM).

Publications (peer reveiwed unless stated otherwise)

Williams, C. Brown, E.A., Lowell, T.V., Shiller, A.M., Hastings, D.W., Shevenell, A.E., and Flower, B.P. (in prep), A multi-proxy approach to reconstructing deglacial salinity and Laurentide Ice Sheet meltwater sources  

Williams, C., Kuffner, I.B., Richey, J.N., and Poore, R.Z. (in prep), Preservation of Limacina inflata (Pteropoda) shells in bi-weekly sediment trap samples: Controls on aragonite dissolution in the northern Gulf of Mexico.

Wickert, A.D., Mitrovica, J.X., Williams, C., and Anderson, R.S. Mississippi drainage records the gradual demise of a thin Southern Laurentide Ice Sheet, Nature (in revision)  

Williams, C., Flower, B.P. and Hastings, D.W. (2012), Seasonal Laurentide Ice Sheet melting during the "Mystery Interva" (17.5-14.5 ka), Geology, v. 40, p. 955-958, doi: 10.1130/G33279.1 --- Download Paper (PDF) --- Download Supplemental Material (PDF)

Flower, B.P., Williams, C., Hill, H. and Hastings, D.W., (2011) Laurentide Ice Sheet meltwater and the Atlantic
meridional overturning circulation during the last glacial cycle: A view from the Gulf of Mexico, in Abrupt Climate Change: Mechanisms, Patterns, and Impacts, Geophysical Monograph Series, v. 193, p. 35-56, doi: 10.1029/2010GM001016

Williams, C., Flower, B.P., Hastings, D.W., Guilderson, T.P., Quinn, K.A. and Goddard, E.A. (2010), Deglacial abrupt climate change in the Atlantic Warm Pool: A Gulf of Mexico perspective, Paleoceanography, 25, PA4221, doi:10.1029/2010PA001928 --- Download Paper (PDF) --- Download Auxiliary Material (PDF)

Williams, C. (2009) Meltwater and Abrupt Climate Change During the Last Deglaciation: A
Gulf of Mexico Perspective, College of Marine Science, University of South Florida. Master’s Thesis. *No peer reveiw

Selected Presentations (1st author)

Williams, C., Brown, E.A., Hastings, D.W., Lowell, T.V., Shiller, A.M., Shevenell, A.E., and Flower, B.P. (2012), Deglacial abrupt climate change and Laurentide Ice Sheet meltwater input to the Gulf of Mexico: Implications for the Atlantic Warm Pool and beyond, America Geophysical Union Fall Meeting. Poster Presentation. 

Williams, C., Flower, B.P, Hastings, D.W., Brown, EA., Lowell, T.V., Shevenell, A.E. (2012), Deglacial meltwater input to the Gulf of Mexico: A marine-based record of Laurentide Ice Sheet chronology, Geological Society of America Fall Meeting, *Invited Talk.

Williams, C., Flower, B.P., Hastings, D.W., Brown, E.A., and Lowell, T.V. (2011), A Multi-Proxy Approach to Understanding Deglacial Gulf of Mexico Climate and Laurentide Ice Sheet Chronology, America Geophysical Union Fall Meeting. Poster Presentation.  

Williams, C., Flower, B.P. Hastings, D.W., Guilderson, T.P., Goddard, E.A., Shiller, A.M. (2010), Meltwater
routing and enhanced seasonality during the Younger Dryas and Mystery Interval based on Gulf of Mexico sediments., International Conference for Paleoceanography. Poster Presentation *Won Best Student Poster Award. Poster PDF

Williams, C., Flower, B.P., Hastings, D.W., Shiller, A.M., Goddard, E.A. and Lea, D. (2010), A Multi-Proxy Approach to Deglacial Paleo-Salinity Reconstructions based on Gulf of Mexico Sediments, American Geophysical Union Fall Meeting. Poster presentation.  

Williams, C. and Flower, B.P. (2009), Laurentide Ice Sheet Meltwater and Seasonality Changes
Based on Gulf of Mexico Sediments, 2009 USF College of Marine Science Graduate Student Symposium. Oral Presentation.

Williams, C., Guilderson, T.P., and Flower, B.P. (2009), Radiocarbon variability during the Laschamp Excursion based on Gulf of Mexico sediments, American Geophysical Union Fall Meeting. Poster presentation.  

Williams, C., Flower, B.P., Hastings, D.W. and Randle, N. (2008), Meltwater and Abrupt Climate
Change in the Gulf of Mexico During the Last Glacial Termination, 2008 AGU Fall Meeting. Poster presentation. *Won Outstanding Student Paper Award. Poster PDF

Williams, C. and Flower, B.P. (2008), Meltwater and Climate Variability in the Gulf of Mexico during the Last Glacial Termination, USF College of Marine Science Graduate Student Symposium. Oral Presentation.

Research Cruise Experience

Coral Calcification Project, FL Reef Tract & Dry Tortugas, 14 days, November/December 2011, Dr. Ilsa Kuffner, US Geological Survey, project focuses on marine calcification rates of corals and algae for four sites along the Florida Reef Track and Dry Tortugas. Corals and algae tiles were collected and photographed using SCUBA, and weighed at each site.

R/V Knorr, 22 days, February/March 2010, Dr. David Hollander, USF College of Marine Science and Dr. Paul Baker, Duke University, exploration of the Amazon delta for appropriate sediments to use in climate reconstructions of the Amazon region. Multiple long cores (150-ft), gravity cores, box cores and multi-cores were taken in addition to CTD casts, water filtration transects for particulates, and seismic surveys.

Photo: The USF and NIOZ Science Crew of the 2010 Amazon Cruise on the R/V Knorr: Kara Radabaugh, Enrique Montes, David Hollander, Claudia Zell, Carlie Williams and Julie Richey

R/V Oceanus, 6 days, June 2008, Dr. Daniel McCorkle, Woods Hole Oceanographic Institute, collected live benthic foraminifera using box cores for deep-sea culturing studies that focused on shell chemistry changes due temperature and seawater carbonate ion variability.

R/V Nancy Foster, 4 days, October 2003, Dr. Paul Gayes, Coastal Carolina University, collected data along South Carolina Grand Strand shelf, in search for sand for beach renourishments. Bottom grabs and side scan sonar were used for data collection. After data collection, sediment samples were sieved and analyzed on the basis of composition and grain size.  

Volunteer & Outreach

Chief Scientist & Scientific Diver, Tarpon Springs FL Chapter, SCUBAnauts International (Time commitment: 20-40 hours/month) (12/2011-present)

Education Officer & Scientific Diver, Tarpon Springs FL Chapter, SCUBAnauts International (Time commitment: 15-30 hours/month) (8/2010-12/2011).

• SCUBAnauts is a scientific dive program that provides middle and high school students the opportunity to participate in the long-term study of natural hard bottom, seagrass, and reef habitats of the Florida Springs Coast. As a volunteer diver and science educator, I help train students on scientific fish and coral survey methods, prepare monthly science presentations, and participate in scientific dives (approx. 40 scientific dives/year).

Guest Lecturer/Scientist for the Duke Talent Identification Program (TIP) “Marine Research in the Gulf of Mexico” Course, New College, Sarasota, FL.

• Prepared and presented a full days worth of lectures and hands-on activities on Geological Oceanography to 11th-12th grade students. Topics/activities included the geologic history of Florida and the Gulf of Mexico, an introduction to marine sediments as indicators of the past, identification of foraminifera in global sediment samples using low-powered microscopes, and calculation of foraminiferal Mg/Ca ratios to estimate deglacial sea-surface temperatures (6/19/2011).

Science mentor/Advisor for a high school student’s 3-week independent senior project (Time commitment: 40 hours/week for 3 weeks)

• Developed a 3-week research project and trained one high school student in sediment processing, select foraminifera species identification, picking and preparation for trace metal analysis. The student analyzed and interpreted results, which she then presented to her school. (05/2011-06/2011).