@article {puleo_younger_2022,
	title = {Younger Dryas and early Holocene climate in south Greenland inferred from oxygen isotopes of chironomids, aquatic Moss, and Moss cellulose},
	journal = {Quaternary Science Reviews},
	volume = {296},
	year = {2022},
	month = {11/2022},
	pages = {107810},
	abstract = {Ice core records have long indicated that the Younger Dryas began and ended with large, abrupt climate shifts over Greenland. Key climatic features remain unknown, including the magnitude of warming during the Younger Dryas-Holocene transition along with the seasonality and spatial variability of Younger Dryas climate changes across Greenland. Here, we use geochemical and paleoecological proxies from lake sediments at Lake N14 in south Greenland to address these outstanding questions. Radiocarbon dating and diatom assemblages confirm early deglaciation and isolation of Lake N14 before \~{}13,600~cal~yr BP, consistent with previous work. Oxygen isotope ratios (δ18O) of chironomid head capsules, bulk aquatic moss, and aquatic moss-derived cellulose are used to reconstruct oxygen isotopes of past lake water and annual precipitation. Oxygen isotope proxies indicate annual precipitation δ18O values increased by 5.9{\textendash}7.7{\textperthousand} at the end of the Younger Dryas. Following the Younger Dryas, moss and cellulose δ18O values show a clear decline in precipitation δ18O values of 2{\textendash}3{\textperthousand} from \~{}11,540{\textendash}11,340~cal~yr BP that may correspond with the Preboreal Oscillation. Reconstructed precipitation δ18O values then gradually increased from 11,300{\textendash}10,100~cal~yr BP. All three aquatic organic materials register similar shifts in precipitation δ18O values over time, and they closely parallel the δ18O shifts observed in ice cores. This evidence strongly supports the utility of these methods for reconstructing lake water δ18O, and furthermore precipitation δ18O values where lake water reflects precipitation. The relatively large shift in isotopic composition of precipitation at Lake N14 suggests that shifts in temperature, precipitation seasonality, and/or moisture sources at the end of the Younger Dryas were even larger in south Greenland than they were in central Greenland, most likely because of the proximity to major changes in North Atlantic Ocean circulation. The annual air temperature change estimated at Lake N14 at the end of the Younger Dryas is also very large (\~{}18~{\textpm}~7~{\textdegree}C) compared to the summer warming previously inferred from chironomid species assemblages there (\~{}6~{\textdegree}C). This indicates that the strongest warming at the end of the Younger Dryas occurred in the winter season, consistent with past observations of intensified Younger Dryas seasonality at Lake N14 and elsewhere in Greenland.},
	keywords = {Chironomids, Deglaciation, diatoms, Greenland, Holocene, Micropaleontology, paleoclimatology, paleolimnology, Stable isotopes, Younger Dryas},
	issn = {0277-3791},
	doi = {10.1016/j.quascirev.2022.107810},
	url = {https://www.sciencedirect.com/science/article/pii/S0277379122004413},
	author = {Puleo, Peter J. K. and Masterson, Andrew L. and Medeiros, Andrew S. and Schellinger, Grace and Steigleder, Regan and Woodroffe, Sarah and Osburn, Magdalena R. and Axford, Yarrow}
}
@article {2912,
	title = {Minimum limiting deglacial ages for the out-of-phase Saginaw Lobe of the Laurentide Ice Sheet using optically stimulated luminescence (OSL) and radiocarbon methods},
	journal = {Quaternary Research},
	volume = {97},
	year = {2020},
	month = {Jan-09-2020},
	pages = {71 - 87},
	abstract = {Twenty-four new optically stimulated luminescence (OSL) and radiocarbon ages from sediment cores in nine lakes associated with the Shipshewana and Sturgis moraines in northern Indiana and southern Michigan estimate when recession of the Saginaw Lobe of the Laurentide Ice Sheet was underway in the southern Great Lakes region, USA. Average OSL ages of 23.4 {\textpm} 2.2 ka for the Shipshewana Moraine and 19.7 {\textpm} 2.2 ka for the Sturgis Moraine are considered minimum limiting deglacial ages for these recessional moraines. The much younger radiocarbon ages are consistent with other regional radiocarbon ages from lakes, and record climate amelioration around ~16.5 cal ka BP. Early recession of the interlobate Saginaw Lobe was well underway by 23.4 {\textpm} 2.2 ka, when the adjacent Lake Michigan and Huron-Erie lobes were a few hundred kilometers farther south and near their maximum southerly limits. The results provide the first time constraints when sediment from the Lake Michigan and Huron-Erie lobes began filling the accommodation space left by the Saginaw Lobe. The difference between the oldest radiocarbon and OSL age is 7400 yr for the Shipshewana Moraine and 3400 yr for the Sturgis Moraine.},
	keywords = {Deglaciation, Lake sediment cores, OSL dating, Radiocarbon lag, Saginaw Lobe, Sturgis Moraine},
	issn = {0033-5894},
	doi = {10.1017/qua.2020.12},
	url = {https://www.cambridge.org/core/journals/quaternary-research/article/minimum-limiting-deglacial-ages-for-the-outofphase-saginaw-lobe-of-the-laurentide-ice-sheet-using-optically-stimulated-luminescence-osl-and-radiocarbon-methods/EA67A66F68407581E99D7D3A8F1},
	author = {Fisher, Timothy G. and Dziekan, Mitchell R. and McDonald, Jennifer and Lepper, Kenneth and Loope, Henry M. and McCarthy, Francine M.G. and Curry, B. Brandon}
}
@article {2713,
	title = {A human role in Andean megafaunal extinction?},
	journal = {Quaternary Science Reviews},
	volume = {205},
	year = {2019},
	month = {Jan-02-2019},
	pages = {154 - 165},
	abstract = {A new fossil pollen, Sporormiella, and sediment chemistry record from Lake Llaviucu, Ecuador, spanning the period from 16,280{\textendash}9000 years Before Present, provides a high-resolution record of paleoecological change in the high Andes. The deglacial transition from super-p{\'a}ramo through p{\'a}ramo grasslands, to Andean forest is traced, with near-modern systems being established by c. 11,900 years ago. It is suggested that forest elements probably existed in microrefugial populations close to the ice front. Sporormiella is used as a proxy for megafaunal abundance, and its decline to background levels is inferred to indicate a local extinction event at c. 12,800 years ago. About 1800 years prior to the extinction, charcoal becomes a regular sedimentary component in this very wet valley. An early date for human activity in the valley is suggested, with the direct implication of humans in the extinction of the megafauna.},
	keywords = {Andes, Deglaciation, Ecuador Extinction, Fossil pollen, Human arrival, Pleistocene megafauna, Sporormiella},
	issn = {02773791},
	doi = {10.1016/j.quascirev.2018.12.005},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0277379118307005},
	author = {Raczka, M.F. and Mosblech, N.A. and Giosan, L. and Valencia, B.G. and Folcik, A.M. and Kingston, M. and Baskin, S. and Bush, M.B.}
}
@article {2738,
	title = {Remobilization of old permafrost carbon to Chukchi Sea sediments during the end of the last deglaciation},
	journal = {Global Biogeochemical Cycles},
	year = {2018},
	month = {Jan-12-2019},
	abstract = {Climate warming is expected to destabilize permafrost carbon (PF-C) by thaw-erosion and deepening of the seasonally thawed active layer and thereby promote PF-C mineralization to CO2 and CH4. A similar PF-C remobilization might have contributed to the increase in atmospheric CO2 during deglacial warming after the last glacial maximum. Using carbon isotopes and terrestrial biomarkers (Δ14C, δ13C, and lignin phenols), this study quantifies deposition of terrestrial carbon originating from permafrost in sediments from the Chukchi Sea (core SWERUS-L2-4-PC1). The sediment core reconstructs remobilization of permafrost carbon during the late Aller{\o}d warm period starting at 13,000 cal years before present (BP), the Younger Dryas, and the early Holocene warming until 11,000 cal years BP and compares this period with the late Holocene, from 3,650 years BP until present. Dual-carbon-isotope-based source apportionment demonstrates that Ice Complex Deposit{\textemdash}ice- and carbon-rich permafrost from the late Pleistocene (also referred to as Yedoma){\textemdash}was the dominant source of organic carbon (66 {\textpm} 8\%; mean {\textpm} standard deviation) to sediments during the end of the deglaciation, with fluxes more than twice as high (8.0 {\textpm} 4.6 g{\textperiodcentered}m-2{\textperiodcentered}year-1) as in the late Holocene (3.1 {\textpm} 1.0 g{\textperiodcentered}m-2{\textperiodcentered}year-1). These results are consistent with late deglacial PF-C remobilization observed in a Laptev Sea record, yet in contrast with PF-C sources, which at that location were dominated by active layer material from the Lena River watershed. Release of dormant PF-C from erosion of coastal permafrost during the end of the last deglaciation indicates vulnerability of Ice Complex Deposit in response to future warming and sea level changes.},
	keywords = {carbon isotope, climate change feedback, coastal erosion, Deglaciation, past carbon cycling, permafrost},
	issn = {0886-6236},
	doi = {10.1029/2018GB005969},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018GB005969https://onlinelibrary.wiley.com/doi/pdf/10.1029/2018GB005969https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1029\%2F2018GB005969https://onlinelibrary.wiley.com/doi/pdf/10.1029/2018GB005969},
	author = {Martens, Jannik and Wild, Birgit and Pearce, Christof and Tesi, Tommaso and Andersson, August and Broder, Lisa and O{\textquoteright}Regan, Matt and Jakobsson, Martin and Sk{\"o}ld, Martin and Gemery, Laura and Cronin, Thomas M. and Semiletov, Igor and Dudarev, Oleg V. and Gustafsson, {\"O}rjan}
}
@article { ISI:000364884400008,
	title = {Early deglacial onset of southwestern Greenland ice-sheet retreat on the continental shelf},
	journal = {QUATERNARY SCIENCE REVIEWS},
	volume = {128},
	year = {2015},
	month = {NOV 15},
	pages = {117-126},
	type = {Article},
	abstract = {The Greenland ice sheet (GrIS) advanced onto the continental shelf during the last glacial period. While deglacial records for when the GrIS withdrew onto the modern coastline are relatively abundant, the timing of early GrIS retreat on the shelf is poorly constrained. Here we use planktic foraminiferal delta O-18, sediment grain size, sedimentation rates, and C-14 ages in southeastern Davis Strait core HU87033-008 to develop an early deglaciation chronology of the southwestern GrIS while on the continental shelf. Sedimentation rates, and especially silt and clay fractions, are high between similar to 20.5 and similar to 17.1 ka, suggesting that the southwestern GrIS margin was near or at the shelf break, where it released subglacially derived sediment-laden meltwater. A peak in sedimentation rates of similar to 110 cm ka(-1) between similar to 19.3 ka and similar to 18.6 ka, combined with an initial decrease in planktic delta O-18 of similar to 0.5 per mil, suggests an early deglacial pull back of the GrIS margin from the shelf break with a concurrent increase in surface ocean meltwater discharge. A subsequent planktic delta O-18 decrease of similar to 1.0 per mil combined with a drop in silt and clay sedimentation rates at 18-17 ka likely record further GrIS retreat inland from the shelf break. Terrestrial Be-10 surface exposure ages indicate that the GrIS margin remained on the continental shelf until similar to 11 ka, yet the cause of this subsequent ice-margin stability on the inner shelf is not known. Our new records provide the first evidence that the southwestern GrIS margin may have begun to deglaciate at the same time as other Northern Hemisphere ice sheets. As Labrador Sea water temperatures likely remained near glacial values until similar to 15 ka, we suggest that initial southwestern GrIS retreat was in response to rising global sea level from retreat of other ice sheets and/or the initial deglacial rise in boreal summer insolation. (C) 2015 Elsevier Ltd. All rights reserved.},
	keywords = {Davis Strait, Deglaciation, Greenland, Retreat forcings, sea level, Sedimentation rate},
	issn = {0277-3791},
	doi = {10.1016/j.quascirev.2015.10.008},
	author = {Winsor, Kelsey and Carlson, Anders E. and Welke, Bethany M. and Reilly, Brendan}
}
@article { ISI:000359889700007,
	title = {Millennial-scale fluctuations of the European Ice Sheet at the end of the last glacial, and their potential impact on global climate},
	journal = {QUATERNARY SCIENCE REVIEWS},
	volume = {123},
	year = {2015},
	month = {SEP 1},
	pages = {113-133},
	type = {Article},
	abstract = {Reconstructing Northern Hemisphere ice-sheet oscillations and meltwater routing to the ocean is important to better understand the mechanisms behind abrupt climate changes. To date, research efforts have mainly focused on the North American (Laurentide) ice-sheets (LIS), leaving the potential role of the European Ice Sheet (EIS), and of the Scandinavian ice-sheet (SIS) in particular, largely unexplored. Using neodymium isotopes in detrital sediments deposited off the Channel River, we provide a continuous and well-dated record for the evolution of the EIS southern margin through the end of the last glacial period and during the deglaciation. Our results reveal that the evolution of EIS margins was accompanied with substantial ice recession (especially of the SIS) and simultaneous release of meltwater to the North Atlantic. These events occurred both in the course of the EIS to its LGM position (i.e., during Heinrich Stadial -HS- 3 and HS2; similar to 31-29 ka and similar to 26-23 ka, respectively) and during the deglaciation (i.e., at similar to 22 ka, similar to 20-19 ka and from 18.2 +/- 0.2 to 16.7 +/- 0.2 ka that corresponds to the first part of HS1). The deglaciation was discontinuous in character, and similar in timing to that of the southern LIS margin, with moderate ice-sheet retreat (from 22.5 +/- 0.2 ka in the Baltic lowlands) as soon as the northern summer insolation increase (from similar to 23 ka) and an acceleration of the margin retreat thereafter (from similar to 20 ka). Importantly, our results show that EIS retreat events and release of meltwater to the North Atlantic during the deglaciation coincide with AMOC destabilisation and interhemispheric climate changes. They thus suggest that the EIS, together with the LIS, could have played a critical role in the climatic reorganization that accompanied the last deglaciation. Finally, our data suggest that meltwater discharges to the North Atlantic produced by large-scale recession of continental parts of Northern Hemisphere ice sheets during HS, could have been a possible source for the oceanic perturbations (i.e., AMOC shutdown) responsible for the marine-based ice stream purge cycle, or so-called HE{\textquoteright}s, that punctuate the last glacial period. (C) 2015 Elsevier Ltd. All rights reserved.},
	keywords = {Channel River, Deglaciation, European ice-sheet, Meltwater, Neodymium, Termination},
	issn = {0277-3791},
	doi = {10.1016/j.quascirev.2015.06.010},
	author = {Toucanne, Samuel and Soulet, Guillaume and Freslon, Nicolas and Jacinto, Ricardo Silva and Dennielou, Bernard and Zaragosi, Sebastien and Eynaud, Fr{\'e}d{\'e}rique and Bourillet, Jean-Francois and Bayon, Germain}
}
@article {2587,
	title = {Deglacial ?18O and hydrologic variability in the tropical Pacific and Indian Oceans},
	journal = {Earth and Planetary Science Letters},
	volume = {387},
	year = {2014},
	month = {Jan-02-2014},
	pages = {240 - 251},
	abstract = {Evidence from geologic archives suggests that there were large changes in the tropical hydrologic cycle associated with the two prominent northern hemisphere deglacial cooling events, Heinrich Stadial 1 (HS1; \~{}19 to 15 kyr BP; kyr BP = 1000 yr before present) and the Younger Dryas (\~{}12.9 to 11.7 kyr BP). These hydrologic shifts have been alternatively attributed to high and low latitude origin. Here, we present a new record of hydrologic variability based on planktic foraminifera-derived δ18O of seawater (δ18Osw) estimates from a sediment core from the tropical Eastern Indian Ocean, and using 12 additional δ18Osw records, construct a single record of the dominant mode of tropical Eastern Equatorial Pacific and Indo-Pacific Warm Pool (IPWP) hydrologic variability. We show that deglacial hydrologic shifts parallel variations in the reconstructed interhemispheric temperature gradient, suggesting a strong response to variations in the Atlantic Meridional Overturning Circulation and the attendant heat redistribution. A transient model simulation of the last deglaciation suggests that hydrologic changes, including a southward shift in the Intertropical Convergence Zone (ITCZ) which likely occurred during these northern hemisphere cold events, coupled with oceanic advection and mixing, resulted in increased salinity in the Indonesian region of the IPWP and the eastern tropical Pacific, which is recorded by the δ18Osw proxy. Based on our observations and modeling results we suggest the interhemispheric temperature gradient directly controls the tropical hydrologic cycle on these time scales, which in turn mediates poleward atmospheric heat transport.},
	keywords = {Deglaciation, Eastern Equatorial Pacific, heat transport, Indo-Pacific, δ18O of seawater},
	issn = {0012821X},
	doi = {10.1016/j.epsl.2013.11.032},
	url = {https://doi.org/10.1016/j.epsl.2013.11.032},
	author = {Gibbons, Fern T. and Oppo, Delia W. and Mohtadi, Mahyar and Rosenthal, Yair and Cheng, Jun and Liu, Zhengyu and Linsley, Braddock K.}
}
