@article {2688,
	title = {Holocene temperature and landscape history of southwest Greenland inferred from isotope and geochemical lake sediment proxies},
	journal = {Quaternary Science Reviews},
	volume = {239},
	year = {2020},
	month = {Jan-07-2020},
	pages = {106358},
	abstract = {Terrestrial temperature reconstructions from the ice-free margins of Greenland are critical for constraining the sensitivity of the Greenland ice sheet to past climate change. Numerous investigations have clarified the glacial history of southwest Greenland in recent decades; however, very few local quantitative temperature reconstructions exist as context for changes in the cryosphere. We examine sedimentary records from two lakes south of Nuuk, Greenland (informally named lakes T1 and T2), and investigate millennial scale Holocene climate change using a multi-proxy approach. Changes in X-Ray fluorescence spectroscopy (XRF), δ15N, δ13C and biogenic silica concentrations of bulk lake sediments mark the transition from a marine environment to isolated lakes as relative sea level fell in the early Holocene. δ18O values of subfossil insects (chironomids) from lakes T1 and T2 decreased by 2{\textendash}3{\textperthousand} from c. 8.8 ka BP (minimum limiting age for the onset of lacustrine sediment deposition in lake T2; ka BP = thousands of years before 1950) to 1 ka BP. Existing isotope-independent temperature reconstructions from the west coast of Greenland suggest that these changes in δ18O values accompanied gradual cooling of 2{\textendash}4 {\textdegree}C, concomitant with decreasing summer insolation. There is widespread regional evidence that this cooling resulted in progressive regrowth of local glaciers and of the ice sheet. The regional consensus on the magnitude of this temperature change indicates that the local, modern modeled temperature - precipitation δ18O relationship cannot be used to quantify millennial-scale temperature changes at these sites through the Holocene. This reinforces that studies utilizing δ18O-based proxies to infer temperature change should carefully assess local isotope-temperature relationships over space and time.},
	keywords = {Chironomids, glaciers, Greenland, Isolation basins, lake sediments, oxygen isotopes, Paleotemperatures, Stable isotopes},
	issn = {02773791},
	doi = {10.1016/j.quascirev.2020.106358},
	url = {https://www.sciencedirect.com/science/article/pii/S0277379120303206},
	author = {Lasher, G. Everett and Axford, Yarrow and Masterson, Andrew L. and Berman, Karalyn and Larocca, Laura J.}
}
@article {2689,
	title = {Local glaciers record delayed peak Holocene warmth in south Greenland},
	journal = {Quaternary Science Reviews},
	volume = {241},
	year = {2020},
	month = {Jan-08-2020},
	pages = {106421},
	abstract = {Local glaciers and ice caps (GICs) respond sensitively and quickly, on the scale of decades to centuries, to climate variations. Continuous records of past fluctuations in GIC size provide information on the timing and magnitude of Holocene climate shifts, and a longer-term perspective on 21st century glacier retreat. Although there is broad-scale agreement on millennial-scale trends in Holocene climate variability and fluctuations in local GICs in Greenland, regional variations are only loosely constrained. Here we present three Holocene proglacial lake sediment records from South Greenland, an area with abundant local glaciers but few Holocene-length paleoclimate records. In addition, we use geospatial analysis to model past equilibrium-line altitudes (ELAs) and thereby constrain the magnitude of ablation-season temperature change during the warmest and coolest periods of the Holocene. Physical and geochemical sedimentary characteristics show that two of the proglacial lakes continued to receive glacial meltwater input until \~{}7.3 and \~{}7.1 ka BP. The survival of local glaciers implies that South Greenland remained relatively cool, and that summer temperatures gradually warmed, but did not warm well beyond 1.2 {\textdegree}C above present in the early Holocene. In the mid-Holocene, from \~{}7.1 to 5.5 ka BP, organic sedimentation at these two sites indicates that local glaciers became very small, or more likely melted away completely. The glaciers within the third lake{\textquoteright}s catchment melted away prior to \~{}5.2 ka BP, as sediments deposited earlier in the Holocene could not be dated at this site. We estimate that summer temperatures increased by at least 1.2{\textendash}1.8 {\textdegree}C above present by \~{}7.3{\textendash}7.1 ka BP. Our results are consistent with other observations that suggest a north-to-south gradient in the timing of Holocene thermal maximum conditions, with southern Greenland experiencing a delayed warming relative to other regions in Greenland. As summer temperatures cooled in the Neoglacial, our records show that sustained glacier regrowth began \~{}3.1 ka BP with glaciers in the southernmost catchment, which at present, receive the most precipitation. In the other two catchments, which host smaller glaciers in a drier environment, regrowth began at \~{}1.3 and \~{}1.2 ka BP, the timing of which is in agreement with other glacial records from the Arctic Atlantic region. Local glaciers reached their maximum late Holocene extents during a cooler, second phase of the Little Ice Age (LIA) \~{}0.2-0.1 ka BP, that we estimate was at least 0.4{\textendash}0.9 {\textdegree}C cooler than present. Overall, these findings improve understanding of the spatio-temporal dynamics of Holocene glacier and climate change in Greenland, potentially yielding valuable information about their future response.},
	keywords = {Equilibrium-line altitudes, Greenland, Holocene thermal maximum, lake sediments, Little ice age, Mountain glaciers, Paleotemperatures},
	issn = {02773791},
	doi = {10.1016/j.quascirev.2020.106421},
	url = {https://www.sciencedirect.com/science/article/pii/S0277379120303838},
	author = {Larocca, Laura J. and Axford, Yarrow and Bj{\o}rk, Anders A. and Lasher, G. Everett and Brooks, Jeremy P.}
}
@conference {1587,
	title = {A Champlain Sea phocid seal fossil from the Champlain Lowland at Plattsburgh, New York},
	volume = {42},
	year = {2010},
	note = {id: 2214; Source type: conferencepapers\&proceedings; Object type: Article; Object type: Conference Paper; Copyright: GeoRef, Copyright 2010, American Geological Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States; CSAUnique: 2010-092590; AccNum: 2010-092590; ISSN: 0016-7592; CODEN: GAAPBC},
	month = {2010},
	pages = {68},
	publisher = {Geological Society of America (GSA), Boulder, CO, United States (USA)},
	organization = {Geological Society of America (GSA), Boulder, CO, United States (USA)},
	address = {United States (USA)},
	abstract = {A SUNY Plattsburgh environmental geotechnology class uncovered several bones, most likely from a harbor seal (Phoca vitulina), from exposures of Champlain Sea mud at the former Plattsburgh Air Force Base marina. The glacial section at the site contains a complete record of late Wisconsinan deglaciation in the Champlain lowland. A 1.5 to 2.0 meter thick section of fresh water ostracode (Candona subtriangulata) bearing, thinly laminated proglacial lacustrine rhythmites overlie massive gray diamicton near the base of the section. The lacustrine rhythmites contain a 0.0 to 0.2 meter thick layer of medium sand that may record one or more breakout floods from the Ontario and St. Lawrence lowlands. The lacustrine rhythmites grade upward to thinly laminated transitional rhythmites that contain marine and fresh water microfaunal assemblages. Approximately 1.5 to 2.0 meters of thinly laminated to massive, fossiliferous marine mud overlies the transitional facies, which in turn grades upward to an approximately 7-meter thick section of horizontally bedded silt and sand. The seal bones came from massive marine mud just below the transition to silt and sand. The accidental fossil find occurred as the class collected mud samples for a slope stability analysis of the bluffs along the present shoreline of Lake Champlain. The collection consists of the tibia and fibula from both legs, four vertebrae, four ribs, an astragalus, a tarsal bone, a phalange, a molar and half of the mandible with a canine tooth attached. Collagen extracted from a piece of fibula has been sent to the National Ocean Sciences Accelerator Mass Spectrometry Facility (NOSAMS) for radiocarbon dating. The find represents the second phocid fossil recovered from the Champlain lowland. The left tibial shaft from another harbor seal, originally misidentified as a hooded seal (Cystophora cristata), was found in Plattsburgh in 1901. Harbor seals on the east coast of North America presently range from the mid-Atlantic region to the Canadian Arctic.},
	keywords = {11, 24, bones, Carnivora, Cenozoic, Champlain Lowland, Champlain Sea, Chordata, Clinton County New York, Eutheria, lacustrine environment, Lake Champlain, lake sediments, Mammalia, New York, North America, Phoca, Phocidae, Pinnipedia, planar bedding structures, Plattsburgh New York, Pleistocene, Quaternary, Quaternary geology, rhythmite, sedimentary structures, sediments, taphonomy, Tetrapoda, Theria, United States, upper Pleistocene, upper Wisconsinan, Vertebrata, Vertebrate paleontology, Wisconsinan},
	author = {Franzi, David A. and Feranec, Robert and Rayburn, John A.}
}
