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Person

Clarke A Knight

Research Geographer
Email: cknight@usgs.gov
ORCID: 0000-0003-0002-6959

Location
345 Middlefield Road
Menlo Park , CA 94025
US
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The data herein are geochemical (from X-Ray fluorescence spectrometry), grain size (percent clay, silt, sand), lithological (loss on ignition data), bathymetric, reconstructed IVT, and radioactive isotopes (14-C, 210-Pb, 226-Ra, and 137-Cs). These data were collected from sediments from Leonard Lake, Mendocino County, California, USA starting in 2014. Together, these data provide evidence for a record of extreme precipitation going back three millennia, showing regional pluvial and drought cycles.
The dataset include raw pollen counts, age model data, and pollen accumulation rates with uncertainty estimates for seven lake sites in the Klamath Mountains, California, USA. The raw pollen counts reflect the relative abundance of major taxa from the vegetation surrounding each lake site (n=7) at 5 different time periods. The age model data provides a Bayesian-based estimate of the sediment's age and the associated uncertainty where pollen samples were also collected and counted (~1850, 1880, 1930, 1970, 2018 AD). Lastly, the pollen accumulation rates dataset encompasses the pollen accumulation rates for each taxa at each time step across all lakes plus the cumulative uncertainty with each calculation, as estimated...
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These data are the geochemical (from X-ray fluorescence spectrometry), grain size, lithological (loss on ignition), diatom assemblages (taxa counts), bathymetric, and radioactive isotopes (210-Pb, 137Cs) from sediments from Wildcat Lake, Point Reyes National Seashore, California, USA starting in 2021. Taken together, they provide evidence for extreme precipitation events linked to atmospheric rivers. They also indicate anthropogenic impacts in the watershed.
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