10,000 years of hydrologic variability in maine (and north dakota)
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10,000 years of hydrologic variability in Maine (and North Dakota). George L. Jacobson Maine SC 12 July 2012 AASC Sandestin , FL. Northern Appalachian/Acadian Ecoregion includes extensive topographic, climatic, and geologic variability. Plant-hardiness zones reveal the same tight gradient. - PowerPoint PPT PresentationTRANSCRIPT
10,000 years of hydrologic variability in Maine
(and North Dakota)
George L. JacobsonMaine SC
12 July 2012
AASC Sandestin, FL
Northern Appalachian/Acadian Ecoregion includes extensive topographic, climatic, and geologic
variability
Plant-hardiness zones reveal the same tight gradient.
Climate Change Institute (formerly Institute for Quaternary and Climate Studies)
The University of MaineOrono, ME
• Climatology/Paleoclimatology• Historic climatology• Terrestrial paleoecology• Paleolimnology• Prehistoric archaeology• Glacial geology and glaciology • Atmospheric chemistry (incl. ice cores)• Geochemistry• Maine State Climatologist (GLJ)
40th Anniversary in 2012
Climate Change InstituteThe University of Maine
Central question:What is the natural variability of the earth’s climate, and what are the underlying mechanisms?
Spring runoff has moved earlier by nearly a month since 1952
Changes in annual flow cycles vary N-S in New England
Krista Ricupero (MS Thesis, University of Maine, 2009); S. Jain advisor.
Atlantic Salmon presence in Maine rivers depends on water conditions (hence climate)
Atlantic salmon present in rivers
wet
dry
Early-Holocene insolation (precession-cycle) produced warm, dry conditions with many fires
in Maine.
wet
dry
Peat chem.Peat chem.
Lake levelsLake levels
Kettle Lake, near Williston, North Dakota
10,000 years of climate, showing moisture variations
blue = moistgreen = intermediatered & orange = dry
Eric C. Grimm et al. (2011) Quaternary Science Reviews 30:2626-2650.
Most extreme drought: 9.25 kaMost extreme drought: 9.25 ka
Analog for coming warm-dry times?
Analog for coming warm-dry times?
Discussion?
Peak Flows on Mousam River
Courtesy of Robert Lent, USGS, Augusta, ME
