@article {hurwitz_yellowstones_2020,
	title = {Yellowstone{\textquoteright}s Old Faithful Geyser Shut Down by a Severe Thirteenth Century Drought},
	journal = {Geophysical Research Letters},
	volume = {47},
	number = {20},
	year = {2020},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2020GL089871},
	month = {10/2020},
	pages = {e2020GL089871},
	abstract = {To characterize eruption activity of the iconic Old Faithful Geyser in Yellowstone National Park over past centuries, we obtained 41 new radiocarbon dates of mineralized wood preserved in the mound of silica that precipitated from erupted waters. Trees do not grow on active geyser mounds, implying that trees grew on the Old Faithful Geyser mound during a protracted period of eruption quiescence. Rooted stumps and root crowns located on higher parts of the mound are evidence that at the time of tree growth, the geyser mound closely resembled its current appearance. The range of calibrated radiocarbon dates (1233{\textendash}1362 CE) is coincident with a series of severe multidecadal regional droughts toward the end of the Medieval Climate Anomaly, prior to the onset of the Little Ice Age. Climate models project increasingly severe droughts by mid-21st century, suggesting that geyser eruptions could become less frequent or completely cease.},
	keywords = {drought, Medieval Climate Anomaly, mineralization, Old Faithful Geyser, radiocarbon, Yellowstone},
	issn = {1944-8007},
	doi = {10.1029/2020GL089871},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2020GL089871},
	author = {Hurwitz, Shaul and King, John C. and Pederson, Gregory T. and Martin, Justin T. and Damby, David E. and Manga, Michael and Hungerford, Jefferson D. G. and Peek, Sara}
}
@article {2716,
	title = {A 12,700-year history of paleolimnological change from an Andean microrefugium},
	journal = {The Holocene},
	volume = {29},
	year = {2019},
	month = {Jul-02-2020},
	pages = {231 - 243},
	abstract = {We present a 12,6700-yr limnological history of Lake Miski, a high-elevation lake in a wet section of the Peruvian Andes. While many shallow Andean lakes dried up during the mid-Holocene, loss-on-ignition, magnetic susceptibility, and diatom analysis showed that Lake Miski was a constant feature in the landscape. Overall, fluctuations in the fossil diatom communities of Lake Miski tracked changes in insolation, but this was not the only mechanism influencing observed variability. We identify periods when insolation and interactions with the Pacific Ocean may have played a role in structuring local climate and diatom assemblages. The true mid-Holocene Dry Event (MHDE) is manifested in this record between 8000 and 5000 cal BP, but the carbonate stratigraphy and the diatom community indicated that although the level of the lake decreased, it never completely dried out, instead there was higher availability of planktic habitat and stronger mixing than in much of the Holocene. High rates of biological change observed during the late-Holocene in other records from Peru associated with human amplification of climatic signals were not observed in Lake Miski, as this lake may have been too wet and remote to be strongly influenced by human activity. Because of the presence of a woodland microrefugium, Lake Miski was suggested to have been an unusually climatically stable and wet location during the regional drying associated with the MHDE. Our new limnological information provides additional insights relating to this discussion. The presence of the observed woodland apparently withstood fluctuations that induced state changes in the lake and diatom flora, underscoring that microrefugia do not equate to {\textquoteleft}unchanging{\textquoteright} hydrologies or climates.},
	keywords = {Andes, diatoms, drought, enso, Holocene, limnology, microrefugia, mid-Holocene dry event, paleoecology},
	issn = {0959-6836},
	doi = {10.1177/0959683618810400},
	url = {http://journals.sagepub.com/doi/10.1177/0959683618810400},
	author = {de Novaes Nascimento, Majoi and Laurenzi, Anne Gail and Valencia, Bryan G and Van, Robert and Bush, Mark}
}
@article {2880,
	title = {The perfect storm: climate change and ancient Maya response in the Puuc Hills region of Yucat{\'a}nAbstract},
	journal = {Antiquity},
	volume = {91},
	year = {2017},
	month = {Jan-04-2017},
	pages = {490 - 509},
	abstract = {Climatic fluctuation is often cited as a major factor in the collapse of Maya civilisation during the Terminal Classic Period (e.g. Luzzadder-Beach et al. 2016). Evidence of how people dealt or failed to deal with it has only recently become a more widespread focus for archaeologists. Investigations at Xcoch in the Puuc Hills show the various ways in which resident populations sought to manage water stores when faced with a climate prone to drought and other meteorological extremes. The study also presents results from the analysis of nearby speleothem laminae, which indicate that severe episodes of flooding and droughts may have contributed to a collapse in the population around AD 850.},
	keywords = {drought, flooding, Maya, M{\'e}xico, speleothem, Xcoch, Yucat{\'a}n},
	issn = {0003-598X},
	doi = {10.15184/aqy.2016.266},
	url = {https://www.cambridge.org/core/product/identifier/S0003598X16002660/type/journal_article},
	author = {Smyth, Michael P. and Dunning, Nicholas P. and Weaver, Eric M. and van Beynen, Philip and Zapata, David Orteg{\'o}n}
}
@article {2447,
	title = {Holocene variability in hydrology, vegetation, fire, and eolian activity in the Nebraska Sand Hills, USA},
	journal = {The Holocene},
	volume = {23},
	year = {2013},
	month = {Jan-04-2013},
	pages = {515 - 527},
	abstract = {This study combined multiple aquatic and terrestrial proxies, including diatoms, pollen, grain size, and bulk-sediment chemistry to reconstruct the history
of three lake sites located in the central Sand Hills of Nebraska, USA. Long-term changes in effective moisture are evident at all sites, with significant
changes occurring at ~6000, ~4000, and ~ 2000 cal. yr BP. Both aquatic and terrestrial indicators suggest that effective moisture was low between
10,000 and ~6000 cal. yr BP, and that this time interval was the driest period of the Holocene. The dominance of benthic and tychoplanktic diatom taxa
indicates relatively shallow lake-level, high sand influx indicates moderately high eolian activity, and the pollen assemblage suggests xeric grasslands with
abundant mud flats. About 6000 cal. yr BP, all three sites experienced an increase in effective moisture. Lake-level rise is indicated by increases in planktic
and tychoplanktic diatoms relative to benthic taxa, while greater abundance of grass pollen and charcoal, and decreased eolian flux indicate stabilized
dunes with dense vegetation sufficient to fuel local fires. A significant hydrologic shift recorded at all sites occurred at ~4000 cal. yr BP. This event was
characterized by substantial lake-level rise, yet decreased grass cover and fire frequency, and increased eolian activity. Water-table rise may have been
caused by a combination of factors including: (1) formation of dune-dams that blocked old drainage channels, (2) reduced grass cover and hence reduced
evapotranspiration, and (3) changes in the frequency and duration of drought. The most likely cause(s) of the differential response of the terrestrial and
aquatic systems at this time is not clear, none-the-less the late Holocene was not nearly as dry as the interval prior to 6000 cal. yr BP. The last ~2000
yr were characterized by several short-term fluctuations in lake level, including an interval of drought between 950 and 750 cal. yr BP, coincident with
increased eolian activity during the latter part of the Medieval Climatic Anomaly.},
	keywords = {diatoms, drought, Holocene climate change, lakes, Nebraska Sand Hills, pollen},
	issn = {0959-6836},
	doi = {10.1177/0959683612463100},
	url = {http://journals.sagepub.com/doi/10.1177/0959683612463100},
	author = {Schmieder, Jens and Fritz, Sherilyn C and Grimm, Eric C and Jacobs, Kimberly C and Brown, Kendrick J and Swinehart, James B and Porter, Stephen C}
}
