A Handheld X-ray fluorescence (XRF) scans the sediment samples and provides concentration of most elements within 90 seconds of scanning time. Multi-proxy characterization of the Hurricane Wilma (2005) storm deposit in sediment cores from the Shark River Slough, southwestern Everglades Qiang Yao, Kam-biu Liu, Victor H. Rivera-Monroy, Presenter Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA Funded by NSF (DDRI grant) and Inter-American Institute for Global Change Research (IAI); Logistical support provided by FCE-LTER, Florida International University (FIU) & Everglades National Park (ENP) 1.To identity the sedimentary characteristics of Hurricane Wilma (2005) by loss-on- ignition, pollen and XRF analyses. 2.To identify paleo-hurricane activities in this particular sedimentary record by using Wilma as a modern analog. 3.To integrate palynology and paleotempestology to produce the first multi-proxy record of the long-term response of coastal wetlands to recurrent hurricanes in the ENP. 1.Peat started to continuously accumulate from 7500 BP at site SRM. 2.Multi-proxy analyses show that the Wilma layer has higher content of marine plankton, carbonates, clastic sediments, and regional pollen types. 3.Four (4) other paleo-hurricane events were identified by using Wilma as a modern analog. Study Sites Acknowledgments Results and Discussion The study site “SRM” is located at the mouth of Shark River, which experienced forest mortality and defoliation caused by hurricane Wilma. A 5.25 m core was retrieved from this site to serve as the master core for our assessment of several variables including loss-on-ignition, pollen, and geochemistry. Loss-on-ignition analysis was performed at 1 cm intervals. Samples were burned at 105, 550, and 1000 o C to calculate % water (wet), % organics (dry), and % carbonates (dry), respectively. Conclusions Age model of core SRM 1.Peat started to accumulated from 7500 BP. 2.6 radiocarbon dates suggest a continuous deposition throughout the Holocene. Loss-on-ignition (LOI) of core SRM 1.Core SRM-1 consists of 4 different sediment types, including basal clay ( cm), marl ( cm), peat ( cm), and calcareous clastic sediments (10- 1 cm). 2.The Wilma layer at top 10 cm consists of low-water and low-organic clastic material. Multi-proxy signature of Hurricane Wilma 1.The top 10 cm of the calcareous clastic sediments in core SRM was deposited by Hurricane Wilma. 2.Multi-proxy analyses show that this sediment layer have higher concentrations of marine plankton (foraminifera and dinoflagellates), carbonates, Ca, Sr, and Zr than in the underlying peat. 3.Pollen assemblage in the Wilma deposits represents a distinct regional pollen signal rather than a local pollen signal (high percentages of Conocarpus, Pinus, Quercus and Chenopodiaceae-Amaranthaceae). Paleo-hurricane events 1.Event 4: around 350 yr BP 2.Event 3: around 1 ka 3.Event 2: around 1.7 ka 4.Event 1: around 2.9 ka 5.Event 4 &3 has similar characteristic as Wilma 6.Events 2 & 1 have high contents of Cl and foraminifera, indicating marine inundation Results and Discussion The Shark River Estuary is frequently impacted by intense hurricanes, which have a significant impact on the structural properties of mangrove forests. The unique location of site SRM, at the mouth of the estuary, permits a multi-proxy study of the overwash sediment layer deposited by Hurricane Wilma (2005) in sediment cores. Using the high-resolution sedimentary and geochemical signature of hurricane Wilma as a modern analog, we identified 4 more paleo- hurricane events in this sedimentary record. The post-hurricane regeneration pattern of mangrove forests in the Everglades is revealed by pollen analysis. Pollen analysis was performed for core SRM at 10 to 15 cm intervals. All pollen samples were treated with standard chemical treatment; most samples were counted to 300 grains/sample. Sediment cores were retrieved by a Russian peat borer. The complete sedimentary sequence contains 4.5 meters of peat overlying calcareous clastic sediments. Research and Experimental design Research Objectives Research Problem