@article {428,
	title = {Millennial-scale climate variability during the Last Glacial period in the tropical Andes},
	journal = {Quaternary Science Reviews},
	volume = {29},
	year = {2010},
	note = {id: 1886; 584JY Times Cited:5 Cited References Count:59Y},
	pages = {1017-1024},
	abstract = {Millennial-scale climate variation during the Last Glacial period is evident in many locations worldwide, but it is unclear if such variation occurred in the interior of tropical South America. and, if so, how the low-latitude variation was related to its high-latitude counterpart A high-resolution record, derived from the deep drilling of sediments on the floor of Lake Titicaca in the southern tropical Andes, is presented that shows clear evidence of millennial-scale climate variation between similar to 60 and 20 ka BP This variation is manifested by alternations of two interbedded sedimentary units The two units have distinctive sedimentary, geochemical, and paleobiotic properties that are controlled by the relative abundance of terrigenous or nearshore components versus pelagic components The sediments of more terrigenous or nearshore nature likely were deposited during regionally wetter climates when river transport of water and sediment was higher, whereas the sediments of more pelagic character were deposited during somewhat drier climates regionally. The majority of the wet periods inferred from the Lake Titicaca sediment record are correlated with the cold events in the Greenland ice cores and North Atlantic sediment cores. indicating that increased intensity of the South American summer monsoon was part of near-global scale climate excursions (C) 2010 Elsevier Ltd All rights reserved},
	issn = {0277-3791},
	doi = {10.1016/J.Quascirev.2010.01.001},
	author = {Fritz, S. C. and Baker, P. A. and Ekdahl, E. and Seltzer, G. O. and Stevens, L. R.}
}
@article {421,
	title = {Quaternary glaciation and hydrologic variation in the South American tropics as reconstructed from the Lake Titicaca drilling project},
	journal = {Quaternary Research},
	volume = {68},
	year = {2007},
	note = {id: 841; 227AJ Times Cited:9 Cited References Count:63Y},
	pages = {410-420},
	abstract = {A 136-m-long drill core of sediments was recovered from tropical high-attitude Lake Titicaca, Bolivia-Peru, enabling a reconstruction of past climate that spans four cycles of regional glacial advance and retreat and that is estimated to extend continuously over the last 370,000 yr. Within the errors of the age model, the periods of regional glacial advance and retreat are concordant respectively with global glacial and interglacial stages. Periods of ice advance in the southern tropical Andes generally were periods of positive water balance, as evidenced by deeper and fresher conditions in Lake Titicaca. Conversely, reduced glaciation occurred during periods of negative water balance and shallow closed-basin conditions in the lake. The apparent coincidence of positive water balance of Lake Titicaca and glacial growth in the adjacent Andes with Northern Hemisphere ice sheet expansion implies that regional water balance and glacial mass balance are strongly influenced by global-scale temperature changes, as well as by precessional forcing of the South American summer monsoon. (c) 2007 University of Washington. All rights reserved.},
	issn = {0033-5894},
	doi = {10.1016/J.Yqres.2007.07.008},
	author = {Fritz, S. C. and Baker, P. A. and Seltzer, G. O. and Ballantyne, A. and Tapia, P. and Cheng, H. and Edwards, R. L.}
}
@article {979,
	title = {A 17,000 year history of Andean climatic and vegetation change from Laguna de Chochos, Peru},
	journal = {Journal of Quaternary Science},
	volume = {20},
	year = {2005},
	note = {id: 1015},
	pages = {703-714},
	abstract = {The manifestation of major climatic events such as the timing of deglaciation and whether, or not, the Younger Dryas affected Andean systems has garnered considerable recent attention. Even the Holocene is rapidly emerging as a time of considerable interest in Neotropical palaeoclimatology and palaeoecology. The Holocene of the Neotropics is now revealed as a time of some temperature change with precipitation:evaporation ratios fluctuating markedly. Major changes in lake level, ice-accumulation, and vegetation are indicative of changes both in precipitation and temperature regimes. Although global-scale forcing mechanisms may underlie some of these changes, e.g. the precessional rhythm, other variability appears to be localised. In a record from near the upper forest limit of the eastern Peruvian Andes, pollen, charcoal, and sedimentary data suggest that the deglaciational period from ca. 17 000 to ca. 11 500 cal. yr BP was a period of rapid climatic oscillations, set against an overall trend of warming. A warm-dry event is evident between ca. 9500 and ca. 7300 cal. yr BP, and comparisons with other regional archives suggest that it was regional in scale. A ca. 1500-yr periodicity in the magnetic susceptibility data is evident between 12 000 and 6000 cal. yr BP, reaching a peak intensity during the dry event. A weaker oscillation with a 500{\textendash}600-yr periodicity is present throughout much of the Holocene. The uppermost sample of the pollen analysis reveals deforestation as modern human land use simplified the landscape.},
	doi = {10.1002/jqs.983},
	author = {Bush, M. B. and Hansen, B. C. S. and Rodbell, D. T. and Seltzer, G. O. and Young, K. R. and Leon, B. and Abbott, M. B. and Silman, M. R. and Gosling, W. D.}
}
@article {655,
	title = {Hydrologic variation during the last 170,000 years in the southern hemisphere tropics of South America},
	journal = {Quaternary Research},
	volume = {61},
	year = {2004},
	note = {776jhTimes Cited:98Cited References Count:43},
	month = {Jan},
	pages = {95-104},
	abstract = {Despite the hypothesized importance of the tropics in the global climate system, few tropical paleoclimatic records extend to periods earlier than the last glacial maximum (LGM), about 20,000 years before present. We present a well-dated 170,000-year time series of hydrologic variation from the southern hemisphere tropics of South America that extends from modem times through most of the penultimate glacial period. Alternating mud and salt units in a core from Salar de Uyuni, Bolivia reflect alternations between wet and dry periods. The most striking feature of the sequence is that the duration of paleolakes increased in the late Quaternary. This change may reflect increased precipitation, geomorphic or tectonic processes that affected basin hydrology, or some combination of both. The dominance of salt between 170,000 and 140,000 yr ago indicates that much of the penultimate glacial period was dry, in contrast to wet conditions in the LGM. Our analyses also suggest that the relative influence of insolation forcing on regional moisture budgets may have been stronger during the past 50,000 years than in earlier times. (C) 2003 University of Washington. All rights reserved.},
	issn = {0033-5894},
	doi = {10.1016/j.yqres.2003.08.007},
	author = {Fritz, S. C. and Baker, P. A. and Lowenstein, T. K. and Seltzer, G. O. and Rigsby, C. A. and Dwyer, G. S. and Tapia, P. M. and Arnold, K. K. and Ku, T. L. and Luo, S. D.}
}
@article {620,
	title = {A late glacial-Holocene tephrochronology for glacial lakes in southern Ecuador},
	journal = {Quaternary Research},
	volume = {57},
	year = {2002},
	note = {555kpTimes Cited:25Cited References Count:23},
	month = {May},
	pages = {343-354},
	abstract = {Despite the presence of numerous active volcanoes in the northern half of Ecuador, few, if any, distal tephras have been previously recognized in the southern one third of the country. In this article, we document the presence of thin (0.1-1.0-cm-thick) distal tephras comprising glass and/or phenocrysts of hornblende and feldspar in sediment cores from five glacial lakes and one bog in Las Cajas National Park (2degrees40{\textquoteright}-3degrees00{\textquoteright}S, 79degrees00{\textquoteright}-79degrees25{\textquoteright}W). The lake cores contain from 5 to 7 tephras, and each has a diagnostic major element geochemistry as determined from electron microprobe analysis of similar to710 glass shards and similar to440 phenocrysts of feldspar and hornblende. The loss of sodium with exposure to the electron microbeam causes a 10 +/- 7 wt.\% (+/-1sigma) reduction in Na content, which we empirically determined and corrected for before correlating tephras among the sediment cores. We use a similarity coefficient to correlate among the sediment cores; pair-wise comparison of all tephras generally yields an unambiguous correlation among the cores. Six tephras can be traced among all or most of the cores, and several tephras are present in only one or two of the cores. Twenty-six accelerator mass spectrometry (14)C dates on macrofossils preserved in the sediment cores provide the basis for establishing a regional tephrochronology. The widespread tephras were deposited similar to9900, 8800,7300,5300,2500, and 2200 cal yr B.P. The oldest tephras were deposited similar to15,500 and 15,100 cal yr B.P., but these are not found in all cores. Two of the tephras appear correlative with volcaniclastic strata on the flanks of Volcan Cotopaxi and one tephra may correlate with strata on the flanks of Volcan Ninahuilca; both volcanoes are in central Ecuador. The absence of tephras in sediment cores correlative with the numerous eruptions of active volcanoes of the past two millennia implies that the earlier eruptions, which did deposit tephras in the lakes, must have been either especially voluminous, or southerly winds must have prevailed at the time of the eruption, or both. (C) 2002 University of Washington.},
	issn = {0033-5894},
	doi = {10.1006/qres.2002.2324},
	author = {Rodbell, D. T. and Bagnato, S. and Nebolini, J. C. and Seltzer, G. O. and Abbott, M. B.}
}
@article {878,
	title = {Climatic significance of large lakes on the Altiplano of South America},
	journal = {EOS, Transactions, American Geophysical Union},
	volume = {82},
	year = {2001},
	note = {id: 333},
	pages = {751},
	author = {Baker, P. A. and Seltzer, G. O. and Fritz, S. C. and Rigsby, C. A. and Dwyer, G. S.}
}
@article {340,
	title = {The history of South American tropical precipitation for the past 25,000 years},
	journal = {Science},
	volume = {291},
	year = {2001},
	note = {id: 369; Baker, P A Seltzer, G O Fritz, S C Dunbar, R B Grove, M J Tapia, P M Cross, S L Rowe, H D Broda, J P New York, N.Y. Science. 2001 Jan 26;291(5504):640-3.},
	pages = {640-3},
	abstract = {Long sediment cores recovered from the deep portions of Lake Titicaca are used to reconstruct the precipitation history of tropical South America for the past 25,000 years. Lake Titicaca was a deep, fresh, and continuously overflowing lake during the last glacial stage, from before 25,000 to 15,000 calibrated years before the present (cal yr B.P.), signifying that during the last glacial maximum (LGM), the Altiplano of Bolivia and Peru and much of the Amazon basin were wetter than today. The LGM in this part of the Andes is dated at 21,000 cal yr B.P., approximately coincident with the global LGM. Maximum aridity and lowest lake level occurred in the early and middle Holocene (8000 to 5500 cal yr B.P.) during a time of low summer insolation. Today, rising levels of Lake Titicaca and wet conditions in Amazonia are correlated with anomalously cold sea-surface temperatures in the northern equatorial Atlantic. Likewise, during the deglacial and Holocene periods, there were several millennial-scale wet phases on the Altiplano and in Amazonia that coincided with anomalously cold periods in the equatorial and high-latitude North Atlantic, such as the Younger Dryas.},
	issn = {0036-8075 (Print) 0036-8075 (Linking)},
	doi = {10.1126/science.291.5504.640},
	author = {Baker, P. A. and Seltzer, G. O. and Fritz, S. C. and Dunbar, R. B. and Grove, M. J. and Tapia, P. M. and Cross, S. L. and Rowe, H. D. and Broda, J. P.}
}
@article {870,
	title = {Late quaternary climate and hydrology of tropical South America inferred from an isotopic and chemical model of Lake Titicaca, Bolivia and Peru},
	journal = {Quaternary Research},
	volume = {56},
	year = {2001},
	note = {452lzTimes Cited:50Cited References Count:46},
	month = {Jul},
	pages = {1-9},
	abstract = {A simple mass balance model provides insight into the hydrologic, isotopic, and chemical responses of Lake Titicaca to past climatic changes. Latest Pleistocene climate of the Altiplano is assumed to have been 20\% wetter and 5 degreesC colder than today, based on previous modeling. Our simulation of lacustrine change since 15,000 cal yr B.P. is forced by these modeled climate changes. The latest Pleistocene Lake Titicaca was deep, fresh, and overflowing. The latest Pleistocene riverine discharge from the lake was about 8 times greater than the modern average, sufficient to allow the expansion of the great paleolake Tauca on the central Altiplano. The lake delta O-18 value averaged about -13 parts per thousand SMOW (the modern value is about -4.2 parts per thousand). The early Holocene decrease in precipitation caused Lake Titicaca to fall below its outlet and contributed to a rapid desiccation of paleolake Tauca. Continued evaporation caused the 100-m drop in lake level, but only a slight(1-2 parts per thousand) increase (relative to modern) in delta O-18 Of early Holocene lake waters. This Holocene lowstand level of nearly 100 m was most likely produced by a precipitation decrease, relative to modern, of about 40\%, The lake was saline as recently as 2000 cal yr B.P. The timing of these hydrologic changes is in general agreement with calculated changes of insolation forcing of the South American summer monsoon, (C) 2001 University of Washington.},
	issn = {0033-5894},
	doi = {10.1006/qres.2001.2244},
	author = {Cross, S. L. and Baker, P. A. and Seltzer, G. O. and Fritz, S. C. and Dunbar, R. B.}
}
@article {622,
	title = {Subdivision of glacial deposits in southeastern Peru based on pedogenic development and radiometric ages},
	journal = {Quaternary Research},
	volume = {56},
	year = {2001},
	note = {452lzTimes Cited:27Cited References Count:51},
	month = {Jul},
	pages = {31-50},
	abstract = {The Cordillera Vilcanota and Quelccaya Ice Cap region of southern Peru (13 degrees 30{\textquoteright}-14 degrees 00{\textquoteright}S; 70 degrees 40{\textquoteright}-71 degrees 25{\textquoteright}W) contains a detailed record of late Quaternary glaciation in the tropical Andes, Quantification of soil development on 19 moraine crests and radiocarbon ages are used to reconstruct the glacial history. Secondary iron and day increase linearly in Quelccaya soils and clay accumulates at a linear rate in Vilcanota soils, which may reflect the semicontinuous addition of eolian dust enriched in secondary iron to all soils. In contrast, logarithmic rates of iron buildup in soils in the Cordillera Vilcanota reflect chemical weathering; high concentrations of secondary iron in Vilcanota tills may mask the role of eolian input to these soils. Soil-age estimates from extrapolation of field and laboratory data suggest that the most extensive late Quaternary glaciation occurred >70,000 yr B.P. This provides one of the first semiquantitative age estimates for maximum ice extent in southern Peru and is supported by a minimum-limiting age of similar to 41,520 C-14 yr B.P. A late glacial readvance culminated similar to 16,650 cal yr B.P. in the Cordillera Vilcanota, Following rapid deglaciation of unknown extent, an advance of the Quelccaya Ice Cap occurred between similar to 13,090 and 12,800 cal yr B.P., which coincides approximately with the onset of the Younger Dryas cooling in the North Atlantic region. Moraines deposited <394 cal yr B.P. in the Cordillera Vilcanota and <300 cal yr B.P. on the west side of the Quelccaya Ice Cap correlate with Little Ice Age moraines of other regions. (C) 2001 University or Washington.},
	issn = {0033-5894},
	doi = {10.1006/qres.2001.2221},
	author = {Goodman, A. Y. and Rodbell, D. T. and Seltzer, G. O. and Mark, B. G.}
}
@article {879,
	title = {Tropical climate changes at millennial and orbital timescales on the Bolivian Altiplano},
	journal = {Nature},
	volume = {409},
	year = {2001},
	note = {id: 388},
	pages = {167-170},
	abstract = {Tropical South America is one of the three main centres of the global, zonal overturning circulation of the equatorial atmosphere (generally termed the {\textquoteright}Walker{\textquoteright} circulation1). Although this area plays a key role in global climate cycles, little is known about South American climate history. Here we describe sediment cores and down-hole logging results of deep drilling in the Salar de Uyuni, on the Bolivian Altiplano, located in the tropical Andes. We demonstrate that during the past 50,000 years the Altiplano underwent important changes in effective moisture at both orbital (20,000-year) and millennial timescales. Long-duration wet periods, such as the Last Glacial Maximum{\textemdash}marked in the drill core by continuous deposition of lacustrine sediments{\textemdash}appear to have occurred in phase with summer insolation maxima produced by the Earth{\textquoteright}s precessional cycle. Short-duration, millennial events correlate well with North Atlantic cold events, including Heinrich events 1 and 2, as well as the Younger Dryas episode. At both millennial and orbital timescales, cold sea surface temperatures in the high-latitude North Atlantic were coeval with wet conditions in tropical South America, suggesting a common forcing.},
	doi = {10.1038/35055524},
	author = {Baker, P. A. and Rigsby, C. A. and Seltzer, G. O. and Fritz, S. C. and Lowenstein, T. K. and Bacher, N. P. and Veliz, C.}
}
@article {901,
	title = {Holocene hydrological reconstructions from stable isotopes and paleolimnology, Cordillera Real, Bolivia},
	journal = {Quarternary Science Reviews},
	volume = {19},
	year = {2000},
	note = {id: 1206},
	pages = {1801-1820},
	abstract = {Multiproxy analyses of sediment cores from Lago Taypi Chaka Kkota (LTCK) Cordillera Real, Bolivia, provide a record of drier conditions following late Pleistocene deglaciation culminating in pronounced aridity between 6.2 and 2.3 ka B.P. Today LTCK is a glacial-fed lake that is relatively insensitive to changes in P{\textendash}E because it is largely buffered from dry season draw-down through the year-round supply of glacial meltwater. This was not the case during the middle to late Holocene when glaciers were absent from the watershed. Lake-water δFull-size image (<1 K) values inferred from δFull-size image (<1 K) analysis of sediment cellulose range from -12.9 to -5.3{\textperthousand} and average -8.7{\textperthousand} between 6.2 and 2.3 ka B.P. Modern lake-water δFull-size image (<1 K) from LTCK averages -14.8{\textperthousand} which is compatible with the δFull-size image (<1 K) value of -14.3{\textperthousand} for the surface sediment cellulose. Analyses of δFull-size image (<1 K) from modern surface waters in 23 lakes that span the range from glacial-fed to closed basin vary from -16.6 to -2.5{\textperthousand}. This approximates the magnitude of the down-core shift in δFull-size image (<1 K) values in LTCK during the middle to late Holocene from -12.9 to -5.3{\textperthousand}. Strong paleohydrologic change during the middle Holocene is also evident in diatom assemblages that consist of shallow-water, non-glacial periphytic taxa and bulk organic δFull-size image (<1 K) and δFull-size image (<1 K) that show increases likely resulting from degradation of lacustrine organic matter periodically exposed to subaerial conditions. Neoglaciation began after 2.3 ka B.P. as indicated by changes in the composition of the sediments, lower δFull-size image (<1 K) values, and a return to diatom assemblages characteristic of the glacial sediments that formed during the Late Pleistocene. Collectively, these data indicate that the past 2.3 ka B.P. have been the wettest interval during the Holocene. Millennial-scale shifts in the paleohydrologic record of LTCK during the early to middle Holocene conform to other regional paleoclimatic time-series, including Lake Titicaca and Nevado Sajama, and may be driven by insolation and resultant changes in atmospheric circulation and moisture supply. In contrast, an apparent 1200-year lag in the onset of wetter conditions at LTCK (2.3 ka B.P.) compared to Lake Titicaca (3.5 ka B.P.) provides evidence for variable sub-regional hydrologic response to climate change during the middle to late Holocene.},
	doi = {10.1016/S0277-3791(00)00078-0},
	author = {Abbott, M. B. and Wolfe, A. P. and Aravena, R. and Wolfe, A. P. and Seltzer, G. O.}
}
@article {2202,
	title = {A New Estimate of the Holocene Lowstand Level of Lake Titicaca and Implications for Tropical Paleohydrology},
	journal = {The Holocene},
	volume = {10},
	year = {2000},
	note = {id: 1339},
	month = {2000},
	pages = {21-32},
	author = {Cross, S. C. and Baker, P. A. and Seltzer, G. O. and Fritz, S. C.}
}
@article {2174,
	title = {Rapid ice margin fluctuations during the Bolling/Allerod and Younger Dryas intervals in the Peruvian Andes},
	journal = {Quaternary Research},
	volume = {54},
	year = {2000},
	note = {id: 392},
	month = {2000},
	pages = {328-338},
	author = {Rodbell, D. T. and Seltzer, G. O.}
}
@article {623,
	title = {Rapid ice margin fluctuations during the Younger Dryas in the tropical Andes},
	journal = {Quaternary Research},
	volume = {54},
	year = {2000},
	note = {388erTimes Cited:61Cited References Count:66},
	month = {Nov},
	pages = {328-338},
	abstract = {Radiocarbon dated lacustrine sequences in Peru show that the chronology of glaciation during the late glacial in the tropical Andes was significantly out-of-phase with the record of climate change in the North Atlantic region. Fluvial incision of glacial-lake deposits in the Cordillera Blanca, central Peru, has exposed a glacial outwash gravel; radiocarbon dates from peat stratigraphically bounding the gravel imply that a glacier advance culminated between similar to 11,280 and 10,990 C-14 yr B.P.; rapid ice recession followed. Similarly, in southern Peru, ice readvanced between similar to 11,500 and 10,900 C-14 yr B.P. as shown by a basal radiocarbon date of similar to 10,870 C-14 yr B.P. from a lake within 1 ion of the Quelccaya Ice Cap. By 10,900 C-14 yr B.P, the ice front had retreated to nearly within its modern limits. Thus, glaciers in central and southern Peru advanced and retreated in near lockstep with one another. The Younger Dryas in the Peruvian Andes was apparently marked by retreating ice fronts in spite of the cool conditions that are inferred from the partial derivative O-18 record of Sajama ice. This retreat was apparently driven by reduced precipitation, which is consistent with interpretations of other paleoclimatic indicators from the region and which may have been a nonlinear response to steadily decreasing summer insolation. (C) 2000 University of Washington.},
	issn = {0033-5894},
	doi = {10.1006/qres.2000.2177},
	author = {Rodbell, D. T. and Seltzer, G. O.}
}
@article {2215,
	title = {A high resolution ~15,000 year record of El-Nino driven alluviation in southwestern Ecuador},
	journal = {Science},
	volume = {283},
	year = {1999},
	note = {id: 393},
	month = {1999},
	pages = {516-519},
	author = {Rodbell, D. T. and Seltzer, G. O. and Anderson, D. M. and Abbott, M. B. and Enfield, D. B. and Newman, J. H.}
}
