00629nas a2200217 4500008004100000245006100041210006000102490000700162100001700169700002000186700001800206700001300224700001800237700001800255700002200273700001600295700001900311700001500330700001600345856005000361 2015 eng d00aDeglacial hydroclimate for Midcontinental North America.0 aDeglacial hydroclimate for Midcontinental North America0 v831 aVoelker, S.L1 aStambaugh, M.C.1 aGuyette, R.P.1 aFeng, X.1 aGrimley, D.A.1 aLeavitt, S.W.1 aPanyushkina, I.P.1 aGrimm, E.C.1 aMarsicek, J.P.1 aShuman, B.1 aCurry, B.B. uhttps://greatlakes.ltrr.arizona.edu/node/523603817nas a2200157 4500008004100000245013000041210006900171260001100240300001600251490000700267520326700274100002003541700002403561700002403585856005003609 2011 eng d00aA high-resolution record of climate variability and landscape response from Kettle Lake, northern Great Plains, North America0 ahighresolution record of climate variability and landscape respo c6/2011 a2626–26500 v303 a

A decadal-scale multiproxy record of minerals, pollen, and charcoal from Kettle Lake, North Dakota provides a high-resolution record of climate and vegetation change spanning the entire Holocene from the northern Great Plains (NGP) in North America. The chronology is established by over 50 AMS radiocarbon dates. This record exhibits millennial-scale trends evident in other lower-resolution studies, but with much more detail on short-term climate variability and on the rapidity and timing of major climatic shifts. As a proxy for precipitation, we utilize the rate of endogenic carbonate sedimentation, which depends on groundwater inflow, which in turn depends on precipitation. Independent cluster analyses of mineral and pollen data reveal major Holocene mode shifts at 10.73 ka (ka = cal yr BP), 9.25 ka, and 4.44 ka.

The early Holocene, 11.7–9.25 ka, was generally wet, with perhaps a trend to higher evaporation associated with warming temperatures. A switch from calcite to aragonite deposition associated with a severe, but brief drought occurred at 10.73 ka. From 10.73 ka to 9.25 ka, climate was generally humid but punctuated at 100–300 yr intervals by brief droughts, including the most severe drought of the entire Holocene at 9.25 ka. This event was coeval with the 9.3–9.2 ka event in the Greenland ice cores and observed at a number of sites worldwide. In contrast, the prominent 8.2 ka event in Greenland is not remarkable at Kettle Lake. The prominence of the 9.25 event locally in the NGP may be due to a major drawdown and northward retreat of Lake Agassiz at this time, reducing its mesoclimatic effect on the NGP and thrusting the region into an insolation controlled regime.

The mid-Holocene, 9.25–4.44 ka, was characterized by great variability in moisture on a multi-decadal scale, with severe droughts alternating with more humid periods. The high abundance of the weedy but drought intolerant Ambrosia generally during the mid-Holocene and specifically during the multi-decadal drought periods is seemingly paradoxical, but can be explained by high interannual variability of moisture overlaid on the multi-decadal variability.

The late Holocene, 4.44 ka–present, was also characterized by multi-decadal variability in moisture, but was generally wetter than the mid-Holocene and the magnitude of variability was less. The trends in wet-dry mineral, pollen, and charcoal proxies were similar to the mid-Holocene, but late Holocene mineral-pollen assemblages are distinct from mid-Holocene. The shift to wetter climate in the late Holocene was more gradual than the abrupt shift to arid conditions 9.25 ka, which may explain the asymmetric retreat and readvance of forest along the eastern margin of the NGP.

Precipitation variations in the NGP have been linked with Pacific and Atlantic sea-surface temperatures, and mid-Holocene drought in the NGP has been linked with sustained La Niña-like conditions in the Pacific. These linkages may explain the decadal- and millennial-scale variations seen in the NGP, but cause of the prominent century-scale variations remains elusive.

1 aGrimm, Eric, C.1 aDonovan, Joseph, J.1 aBrown, Kendrick, J. uhttps://greatlakes.ltrr.arizona.edu/node/522800625nas a2200181 4500008004100000245013300041210006900174250001600243100001500259700002200274700001800296700001900314700001700333700001300350700001600363700001400379856005000393 2007 eng d00aLate-glacial and early Holocene paleoecology: Schneider farm, Calumet County. In: Late-Glacial History of East-central Wisconsin0 aLateglacial and early Holocene paleoecology Schneider farm Calum aT.S. Hooyer1 aMode, W.N.1 aPanyushkina, I.P.1 aLeavitt, S.W.1 aWilliams, J.W.1 aSantiago, A.1 aGill, J.1 aEdwards, C.1 aGertz, H. uhttps://greatlakes.ltrr.arizona.edu/node/524100575nas a2200157 4500008004100000245014700041210006900188490000700257100002200264700001800286700002000304700001500324700001400339700001400353856005000367 2004 eng d00aTree-ring records of near-Younger Dryas time in Central North America- preliminary results from the Lincoln quarry site, central Illinois, USA0 aTreering records of nearYounger Dryas time in Central North Amer0 v461 aPanyushkina, I.P.1 aLeavitt, S.W.1 aWiedenhoeft, A.1 aNoggle, S.1 aCurry, B.1 aGrimm, E. uhttps://greatlakes.ltrr.arizona.edu/node/5230