1. Holocene Flood Frequency in New England: Large, Episodic Events in the Sediment Record Adam Parris University of Vermont Master’s Thesis Defense April 18, 2003

2. WHY?

3. 2000 2600 5900 6800 8200 9400 50 cm Calendar Years BP MAGLOI Brown et al., Geology, 2000

4. New England Climate Cool, moist Warm, dry Cool, moist Storms Fans Avg. Jennings et al., GSA Bulletin, 2003 Noren et al., Nature, 2002 024681012 Calendar ky BP

6. Questions Does particle size anlaysis of lake sediment cores offer a higher resolution record of storminess? Are there periods and/or cycles of increased storminess in NH & ME, similar to VT & NY? Is the regional storm record in NH & ME similar to other Atlantic records? ●Climatic causes/controls?

7. Reasoner Method Driver Head Barrel Piston 6m

8. Lake Locations

9. DEEPSTEEP Lake Name Surface Area (km 2 ) Max Depth (m) Basin Relief (m) Worthley Pond (ME)1.4315344 Crystal Lake (NH)0.418353 South Pond (NH)0.727.9427 Ogontz Lake (NH)0.30322408 Stinson Lake (NH)1.422655 Sandy Pond (NH)0.1112226

10. Analytical Methods ●Visual Stratigraphic Log ● Visual Stratigraphic Log ● Magnetic Susceptibility (MAG) ● Loss on ignition (LOI) ● AMS- Radiocarbon Analysis ( 14 C) ● Particle Size Analysis ● COMPREHENSIVE PREP ● COMPREHENSIVE PREP ● HIGH RESOLUTION ● HIGH RESOLUTION ● REGIONAL COVERAGE ● REGIONAL COVERAGE

11. Med PS (µm) % LOIMAG (SI) Visual Log 20 60 100 140 180 Depth (cm) Mean PS (µm)

12. Med PS (µm) PS % Volume 20 60 100 140 180 Depth (cm) Mean PS (µm)

13. 10100010100010100010100 10055525-5 100 200 Depth (cm) Mean (µm) Median (µm) Mode (µm) StDev (µm) Kurtosis Skewness

14. Med PS (µm) PS % Volume 20 60 100 140 180 Depth (cm) Mean PS (µm)

15. Size Frequency Distributions Particle Size (µm) Volume %

16. End Member Modeling: Unraveling the size distribution 60 %20 %

17. Particle Size (µm) Coefficient of Determination (r 2 ) Number of end members Median r 2 Estimation of End Members

18. Particle Size (µm) Volume % EM5: Mode= 6µm EM4: Mode= 19µm EM3: Mode= 58µm EM2: Mode= 121µm EM1: Mode= 373µm End Members

19. Proportion of the End Members Depth (cm) 100 200 300 0.01.00.5 0.01.00.5 0.01.00.5 0.01.00.5 EM1 + EM2 EM3EM4EM5 Particle Size (µm) Volume % EM5: Mode= 6µm EM4: Mode= 19µm EM3: Mode= 58µm EM2: Mode= 121µm EM1: Mode= 373µm

20. 80 dates John Southon, Tom Guilderson Lawrence Livermore National Laboratory

21. Time Series Filter ● SSA construction of raw data series ● Remove linear trend of data Peaks > 1σ from ● Peaks > 1σ from reconstruction = reconstruction = SIGNIFICANT EVENT LAYER 200 225 250 275 300 PS

22. 25 65 105 145 185 Depth (cm) 10400102001100 Mean PS (µm) Median PS (µm) %LOIEM1 + EM2

23. MeanMedianMinMax LOI 1σ31281570 LOI 2 σ84232 Mean PS 1 σ39331181 Mean PS 2 σ2018745 Median PS 1 σ37321288 Median PS 2 σ1815652 Coarse EMs 1 σ29221457 Coarse EMs 2 σ1512731 Event Detection Comparison

24. Remove event layers Compress core Events 1400 3000 5200 Dates 1400 2100, 2150 Model Ages 3000, 3120 3400, 3790 4800, 4950 5200

25. 02468101214 Cal. Age (kyr BP) Terrigenous Layer End of record Beginning of record Storm Dates

26. 024681012 Cal Age (kyr BP) Storm Frequency 0.81.42.13.03.96.811.5

27. Frequency (cycles/kyr) Storm Frequency- EMM 5600 yrs 600 yrs 311 yrs

28. Climate in Northeastern USA Storm Frequency Storms Floods 0 2 4 68 10 12 Calendar kyr BP

29. Hurricane Connection Increased storminess in New England = Increased hurricane frequency in Atlantic and Gulf Coast Increased storminess in New England = Increased flooding in Upper Mississippi Valley Modern record of hurricane-related precipitation and flooding

30. Discussion Differing landscape response to precipitation Storm size –More frequent events –Smaller cycles –Radiocarbon uncertainties

31. Discussion Geographic location of study area Proposed mechanisms for hurricane-related storms in New England

32. Conclusions Grain size is an effective physical parameter which detects more frequent events End Member Modeling is a valuable tool for revealing processes reflected in grain size distributions Different patterns of storminess in NH & ME than VT & NY Patterns of storminess in NH & ME connected to hurricane related storms

33. Acknowledgements Paul Bierman Peter Ryan Charlotte Mehrtens Angie Conlan Sarah Brown Kristen Benchley Joseph Haun Sarah Stopper Andy Bosley Stephen Wright Karen Jennings John Southon Tom Guilderson Eric Steig Craig Kochel Without the financial support from NSF and the friendship, support, and collaboration of these people, this project would not be possible. Anders Noren Andrea Lini Andi Lord Maarten Prins Wayne Parris Kathy Parris Krista Parris Laura Mallard