24-19 On the Same Wavelength: Integrating Remote Reflection and Sediment Core Data in Little Lake Sunapee, New Hampshire

Session: Lake Sedimentary Records of Past Climate and Environment (Posters)

Poster Booth No.: 47

Presenting Author:

Authors:

Saks, Caleb S.¹, Bloch, Roger B.², Stroup, Justin S.³, Arcone, Steven A.⁴, Lowell, Thomas V.⁵, Keating, Margaret M.⁶, Drindak, Adrianna J.⁷, Kelly, Meredith A.⁸

(1) Department of Earth Sciences, Dartmouth College, Hanover, , (2) New London, , (3) Department of Earth Sciences, Dartmouth College, Hanover, , (4) West Lebanon, , (5) Department of Earth and Climate Sciences, University of Maine, Orono, , (6) Department of Earth Sciences, Dartmouth College, Hanover, , (7) Department of Earth Sciences, Dartmouth College, Hanover, , (8) Department of Earth Sciences, Dartmouth College, Hanover, ,

Abstract:

Reflection events on seismic and ground penetrating radar (GPR) data are commonly used to infer changes in stratigraphy in lake basins. We are interested in “ground truthing” these types of data and correlating reflection events to measured changes in sediment characteristics including composition and density. As a test case, we focus on Little Lake Sunapee, located in central New Hampshire, which contains sediments deposited during and subsequent to the retreat of the Laurentide Ice Sheet that provide a record of post-glacial climate and environmental change. Here we present detailed coverage of the Little Lake Sunapee sub-bottom sediment stratigraphy based on 50 km of high-resolution Chirp seismic profiles and 20 km of GPR profiles.  These seismic and GPR profiles are the basis for a stratigraphic framework, starting at the time of initial deglaciation.  We present results from an ~5-m long sediment core from a location that aligns with coincident seismic and GPR profiles.  We compare the sediment characteristics including composition, density, magnetic susceptibility, and age with reflection events observed in the seismic data.  We are also collecting new cores that target specific reflection events evident in the Chirp and GPR data. We will present our preliminary results from these cores.  We aim to improve the ability to use seismic and GPR data to infer changes in lake-bottom stratigraphy and sedimentology and, ultimately, to use the combination of these methods to infer past climate and environmental change from lake-sediment records.

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