DOCSLIB.ORG

Constraints on the Origin of Paleolake Expansions in the Central Andes

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Constraints on the Origin of Paleolake Expansions in the Central Andes Earth Interactions x Volume 1 (1997) x Paper No. 1 x Page 1 Copyright q 1997. Paper 1-001, 9,697 Words, 4 Tables, 11 Figures, 1 Mathematica. http://EarthInteractions.org Constraints on the Origin of Paleolake Expansions in the Central Andes Troy A. Blodgett,* John D. Lenters,** and Bryan L. Isacks* *Department of Geological Sciences, Cornell University, Ithaca, New York **Atmospheric Science Program, Cornell University, Ithaca, New York Received 11 March 19; accepted 6 December 1996. ABSTRACT: During the late Pleistocene, at least one episode of lake ex- pansions occurred in the internally draining high plateau region of Bolivia. Some researchers have advocated that a wetter climate associated with a change in atmospheric circulation caused the development of the large paleo- lakes, while others have hypothesized that deglaciation contributed to the wa- ter source for the expanding lakes. From estimates of the potential meltwater stored in the glaciers during their maximum extents, the authors conclude that insuf®cient meltwater was available to ®ll the large paleolakes. However, the meltwater hypothesis remains viable south of the main plateau region where, in ®ve small drainage basins, the volume of available glacial meltwater was 3±16 times greater than the volume of water in the paleolakes. Pollen, dunes, and other eolian features indicate that the region surrounding the Altiplano was much drier during at least one interval of the late Pleistocene. Although the timing of the dry period with respect to the paleolakes is still unknown, a pluvial explanation for the existence of paleolakes seems unlikely. Decreased evaporative loss, however, remains a possible explanation. To understand what factors could have been associated with a decrease in evaporation rates over the drainage basin, an evaporation model is developed based on the energy * Corresponding author address: Troy Blodgett, 2112 Snee Hall, Cornell University, Ithaca, NY 14853. E-mail address: [email protected] Unauthenticated | Downloaded 09/25/21 01:08 PM UTC Earth Interactions x Volume 1 (1997) x Paper No. 1 x Page 2 balance and bulk transfer methods. The model indicates that a 108C drop in air temperature or a doubling in cloud cover could have caused the paleolakes to reach their highest levels. Alternatively, a 50% increase in precipitation rate could have also maintained the paleolakes. KEYWORDS: Paleoclimatology Evapotranspiration Geomorphology Hy- drologic budget Snow and ice 1. Introduction 1.1. Evidence of paleolakes Evidence of former lakes in the central Andes was ®rst documented in the mid- 1800s when explorers observed lacustrine deposits and high shorelines around Lake Titicaca and identi®ed algal-carbonate beach ridges 4 m above the basin ¯oor near Lake Poopo (Figure 1) (Clapperton, 1993). Distinct erosional shore platforms and depositional gravel beach surround most of the salars and lakes between 158 and 238S and throughout much of the internally drained portion of the central Andes. The modern climate encompassing the region of paleolake development is diverse and include both arid regions receiving less than 200 mm of precipitation per year and more humid areas receiving over 800 mm per year. Figure 1. Titicaca±Uyuni±Coipasa±Poopo drainage basin. Within the numerous internally draining basins on the high plateau (Altipla- no), deposits and shorelines corresponding to several episodes of paleolake ex- pansions have been identi®ed. The oldest and highest of the paleolakes identi®ed is Lake Mataro in the basin containing Lake Titicaca. Lake Mataro is tentatively dated as late Pliocene because it lies just above a 2.8 6 0.4 Ma ash bed (Lavenu, 1986). Evidence of two other paleolakes named Lake Cabana and Lake Ballivian have also been found within the Titicaca basin and are roughly mid- to late Pleistocene in age (Clapperton, 1993). During high paleolake phases in the southern Altiplano, the present PoopoÂ, Coipasa, and Uyuni drainage basins were integrated into one basin (Figure 1, Figure 2, Figure 3). Within the Poopo±Coipasa±Uyuni drainage basin, Ahlfeld and Branisa (Ahlfeld and Branisa, 1960) identi®ed conspicuous erosional bench- es cut into the ¯anks of the volcanic stock Cerro Lipillipi at the elevations of 3680, 3685, 3710, and 3735 m. Based on radiocarbon ages of 26,700 to 28,300 yr BP, 25,700 to 26,900 yr BP, and an AMS (accelerator mass spectrometry) date of 30,640 to 31,750 yr BP, the four terraces and a higher depositional shoreline at 3760 m were originally associated with Lake Minchin, while a shoreline consisting of clayey and calcareous diatomites 2±5 m thick at 3720 m was considered evidence of another paleolake named Lake Tauca (Clapperton, 1993; Clayton and Clapperton, 1995; Servant and Fontes, 1978). Since dates acquired by Bills et al. (Bills et al., 1994) show that the maximum level of Lake Minchin (3760 m) was attained by the Tauca lake phase at about 13,790 yr BP, a distinction no longer exists between the maximum elevation of Lake Minchin and Lake Tauca. Additional AMS and uranium series dates corresponding to several lower lake levels indicate that either subsequent lesser high lake phases Unauthenticated | Downloaded 09/25/21 01:08 PM UTC Earth Interactions x Volume 1 (1997) x Paper No. 1 x Page 3 Figure 1. Titicaca±Uyuni±Coipasa±Poopo drainage basin. developed or the Tauca lake phase persisted until about 9500 yr BP (Clayton and Clapperton, 1995; Servant et al., 1995). To avoid confusion associated with new shoreline dates collected within the Uyuni±Coipasa±Poopo basin, we sim- ply consider the highest shoreline level (3760 m) to be the highest elevation attained by the Tauca lake phase. Lower shoreline elevations are considered lower levels of the Tauca lake phase. Although the age of the highest shoreline at 3825 m near the shores of Lake Titicaca has not been established, for our calculations we consider the 3825-m-level part of Tauca (3760 m), because a Unauthenticated | Downloaded 09/25/21 01:08 PM UTC Earth Interactions x Volume 1 (1997) x Paper No. 1 x Page 4 Figure 2. Paleolake and Pleistocene glacier reconstruction within the Titicaca± Uyuni±Coipasa±Poopo drainage basin. highstand in the Lake Titicaca basin is likely to have been contemporaneous with a highstand in the Titicaca±Uyuni±Poopo±Coipasa basin (Wirrmann and Mourguiart, 1995). Servant and Fontes (Servant and Fontes, 1978) also dated shorelines within a small basin to the south that now contains Laguna Khota (Figure 4) at 11,000 to 12,500 yr BP. This small paleolake's age suggests that the cause of the Tauca phase may also have been felt outside of the Uyuni± Coipasa±Poopo drainage basin. Glacial meltwater was one of the ®rst hypotheses proposed to account for Unauthenticated | Downloaded 09/25/21 01:08 PM UTC Earth Interactions x Volume 1 (1997) x Paper No. 1 x Page 5 Figure 3. Schematic pro®le of modern drainage. Thick black lines represent rela- tive slope length and slope gradients (slopes are vertically exaggerat- ed). the paleolake expansions (Servant and Fontes, 1978). Kessler (Kessler, 1984) proposed as an alternative hypothesis that pluvial conditions accounted for the expanded lakes. He argued that the glaciers melted during a regressive lake phase and thus contributed no meltwater to the expansive lake phase. He further proposed that a southerly shift in the intertropical convergence zone had in- creased the amount of Amazonian moisture reaching the plateau and estimated that at least a 30% increase in precipitation would have been required to account for the Lake Tauca (3720 m) shorelines. A similar model was constructed by Hastenrath and Kutzbach (Hastenrath and Kutzbach, 1985), who also rejected the idea that glacial meltwater could account for the paleolakes. They estimated that the expansion of two of the Lake Tauca phases at 3720 and 3760 m resulted from precipitation increases of greater than 50% and 75%, respectively. A de®nitive test of the hypothesis that melting glaciers ®lled the basins would be to reconstruct the former glacier and lake water volumes to see which is greater. This is undertaken in the present study for the Titicaca±Uyuni±Coipasa± Poopo basin as well as for ®ve small basins in the southern Altiplano (Figure 4). Furthermore, since reduced evaporation remains a potential explanation for the lake highstands, an evaporation model is constructed to investigate the sensitivity of evaporation rates to altered atmospheric conditions. 1.2. Modern and late Pleistocene drainage patterns Because many of the drainage basins on the Altiplano over¯owed and coalesced during the paleolake expansions, the modern series of drainage basins have been grouped into just two basins connected by the Desaguadero River (Figure 1, Figure 3). Evidence of basin coalescence has also been documented in modern Unauthenticated | Downloaded 09/25/21 01:08 PM UTC Earth Interactions x Volume 1 (1997) x Paper No. 1 x Page 6 Figure 4. Map showing extent of former glaciers, paleolakes, and present salars/ lakes in the southern Altiplano. time. During the rainy season in the wet year of 1986, water not only reached Lake Poopo as is typical, but the inundation also ¯ooded the Coipasa and Uyuni salars (Roche et al., 1991). One complication to this simple approach is that presently a small drainage area south of Lake Titicaca drains northward when Lake Titicaca is low but drains southward into the Desaguadero River watershed Unauthenticated | Downloaded 09/25/21 01:08 PM UTC Earth Interactions x Volume 1 (1997) x Paper No. 1 x Page 7 when Lake Titicaca is high. For modeling present conditions, we include this alternating drainage as part of the Titicaca basin (Figure 1). However, since the highstand around Lake Titicaca was probably coincident with the Tauca lake phase, and the alternating drainage region area was likely to have drained directly into the Uyuni±Poopo±Coipasa basin during inundation episodes, the alternating drainage area is considered part of the Uyuni±Coipasa±Poopo basin during the Tauca lake phase.
Load more

Recommended publications
  • Salt Lakes and Pans
    SCIENCE FOCUS: Salt Lakes and Pans Ancient Seas, Modern Images SeaWiFS image of the western United States. The features of interest that that will be discussed in this Science Focus! article are labeled on the large image on the next page. (Other features and landmarks are also labeled.) It should be no surprise to be informed that the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) was designed to observe the oceans. Other articles in the Science Focus! series have discussed various oceanographic applications of SeaWiFS data. However, this article discusses geological features that indicate the presence of seas that existed in Earth's paleohistory which can be discerned in SeaWiFS imagery. SeaWiFS image of the western United States. Great Salt Lake and Lake Bonneville The Great Salt Lake is the remnant of ancient Lake Bonneville, which gave the Bonneville Salt Flats their name. Geologists estimate that Lake Bonneville existed between 23,000 and 12,000 years ago, during the last glacial period. Lake Bonneville's existence ended abruptly when the waters of the lake began to drain rapidly through Red Rock Pass in southern Idaho into the Snake River system (see "Lake Bonneville's Flood" link below). As the Earth's climate warmed and became drier, the remaining water in Lake Bonneville evaporated, leaving the highly saline waters of the Great Salt Lake. The reason for the high concentration of dissolved minerals in the Great Salt Lake is due to the fact that it is a "terminal basin" lake; water than enters the lake from streams and rivers can only leave by evaporation.
    [Show full text]
  • The Endemic Gastropod Fauna of Lake Titicaca: Correlation Between
    The endemic gastropod fauna of Lake Titicaca: correlation between molecular evolution and hydrographic history Oliver Kroll1, Robert Hershler2, Christian Albrecht1, Edmundo M. Terrazas3, Roberto Apaza4, Carmen Fuentealba5, Christian Wolff1 & Thomas Wilke1 1Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Germany 2National Museum of Natural History, Smithsonian Institution, Washington, D.C. 3Facultad de Ciencias Biologicas, Universidad Nacional del Altiplano, Puno, Peru 4Instituto de Ecologıa,´ Universidad Mayor de San Andres, La Paz, Bolivia 5Departamento de Zoologia, Universidad de Concepcion, Chile Keywords Abstract Altiplano, Heleobia, molecular clock, phylogeography, species flock. Lake Titicaca, situated in the Altiplano high plateau, is the only ancient lake in South America. This 2- to 3-My-old (where My is million years) water body has had Correspondence a complex history that included at least five major hydrological phases during the Thomas Wilke, Department of Animal Ecology Pleistocene. It is generally assumed that these physical events helped shape the evo- and Systematics, Justus Liebig University lutionary history of the lake’s biota. Herein, we study an endemic species assemblage Giessen, Heinrich Buff Ring 26–32 (IFZ), 35392 in Lake Titicaca, composed of members of the microgastropod genus Heleobia,to Giessen, Germany. Tel: +49-641-99-35720; determine whether the lake has functioned as a reservoir of relic species or the site Fax: +49-641-99-35709; of local diversification, to evaluate congruence of the regional paleohydrology and E-mail: [email protected] the evolutionary history of this assemblage, and to assess whether the geographic distributions of endemic lineages are hierarchical. Our phylogenetic analyses in- Received: 17 February 2012; Revised: 19 April dicate that the Titicaca/Altiplano Heleobia fauna (together with few extralimital 2012; Accepted: 23 April 2012 taxa) forms a species flock.
    [Show full text]
  • Línea Base De Conocimientos Sobre Los Recursos Hidrológicos E Hidrobiológicos En El Sistema TDPS Con Enfoque En La Cuenca Del Lago Titicaca ©Roberthofstede
    Línea base de conocimientos sobre los recursos hidrológicos e hidrobiológicos en el sistema TDPS con enfoque en la cuenca del Lago Titicaca ©RobertHofstede Oficina Regional para América del Sur La designación de entidades geográficas y la presentación del material en esta publicación no implican la expresión de ninguna opinión por parte de la UICN respecto a la condición jurídica de ningún país, territorio o área, o de sus autoridades, o referente a la delimitación de sus fronteras y límites. Los puntos de vista que se expresan en esta publicación no reflejan necesariamente los de la UICN. Publicado por: UICN, Quito, Ecuador IRD Institut de Recherche pour Le Développement. Derechos reservados: © 2014 Unión Internacional para la Conservación de la Naturaleza y de los Recursos Naturales. Se autoriza la reproducción de esta publicación con fines educativos y otros fines no comerciales sin permiso escrito previo de parte de quien detenta los derechos de autor con tal de que se mencione la fuente. Se prohíbe reproducir esta publicación para venderla o para otros fines comerciales sin permiso escrito previo de quien detenta los derechos de autor. Con el auspicio de: Con la colaboración de: UMSA – Universidad UMSS – Universidad Mayor de San André Mayor de San Simón, La Paz, Bolivia Cochabamba, Bolivia Citación: M. Pouilly; X. Lazzaro; D. Point; M. Aguirre (2014). Línea base de conocimientos sobre los recursos hidrológicos en el sistema TDPS con enfoque en la cuenca del Lago Titicaca. IRD - UICN, Quito, Ecuador. 320 pp. Revisión: Philippe Vauchel (IRD), Bernard Francou (IRD), Jorge Molina (UMSA), François Marie Gibon (IRD). Editores: UICN–Mario Aguirre; IRD–Marc Pouilly, Xavier Lazzaro & DavidPoint Portada: Robert Hosfstede Impresión: Talleres Gráficos PÉREZ , [email protected] Depósito Legal: nº 4‐1-196-14PO, La Paz, Bolivia ISBN: nº978‐99974-41-84-3 Disponible en: www.uicn.org/sur Recursos hidrológicos e hidrobiológicos del sistema TDPS Prólogo Trabajando por el Lago Más… El lago Titicaca es único en el mundo.
    [Show full text]
  • Phylogenomics of the Hyalella Amphipod Species-Flock of The
    www.nature.com/scientificreports OPEN Phylogenomics of the Hyalella amphipod species‑fock of the Andean Altiplano Francesco Zapelloni1,3, Joan Pons2,3, José A. Jurado‑Rivera1, Damià Jaume2 & Carlos Juan1,2* Species diversifcation in ancient lakes has enabled essential insights into evolutionary theory as they embody an evolutionary microcosm compared to continental terrestrial habitats. We have studied the high‑altitude amphipods of the Andes Altiplano using mitogenomic, nuclear ribosomal and single‑ copy nuclear gene sequences obtained from 36 Hyalella genomic libraries, focusing on species of the Lake Titicaca and other water bodies of the Altiplano northern plateau. Results show that early Miocene South American lineages have recently (late Pliocene or early Pleistocene) diversifed in the Andes with a striking morphological convergence among lineages. This pattern is consistent with the ecological opportunities (access to unoccupied resources, initial relaxed selection on ecologically‑ signifcant traits and low competition) ofered by the lacustrine habitats established after the Andean uplift. Lakes with an uninterrupted history of more than 100,000 years (ancient lakes) may be considered as natural laboratories for evolutionary research as they constitute hotspots of aquatic animal speciation and phenotypic diversity1. Changes in lake size and episodes of desiccation are considered to be critical factors in the speciation and extinction of lake faunas, with the creation of new habitats afer lake expansions as the primary driver of intra-lake diversifcation2–4. For instance, cichlid radiations in the East African Lakes seem to have been trig- gered by lake expansions afer periods of intense desiccation, with the surviving species flling up empty niches afer lake reflling2.
    [Show full text]
  • Climate Variability of the Tropical Andes Since the Late Pleistocene
    Adv. Geosci., 22, 13–25, 2009 www.adv-geosci.net/22/13/2009/ Advances in © Author(s) 2009. This work is distributed under Geosciences the Creative Commons Attribution 3.0 License. Climate variability of the tropical Andes since the late Pleistocene A. Brauning¨ Institute for Geography, University of Erlangen-Nuremberg, Germany Received: 10 May 2009 – Revised: 12 June 2009 – Accepted: 17 June 2009 – Published: 13 October 2009 Abstract. Available proxy records witnessing palaeoclimate nual variations of summer rainfall on the Altiplano, which of the tropical Andes are comparably scarce. Major impli- is generally controlled by upper tropospheric easterlies and cations of palaeoclimate development in the humid and arid by the frequency and intensity of the El Nino-Southern˜ Os- parts of the Andes are briefly summarized. The long-term cillation (ENSO) phenomenon (Garreaud et al., 2003, 2008; behaviour of ENSO has general significance for the climatic Zech et al., 2008). The latter is modulated by the thermal history of the Andes due to its impact on regional circula- gradient of sea surface temperatures (SST) between the east- tion patterns and precipitation regimes, therefore ENSO his- ern and western tropical Pacific and by the strength and po- tory derived from non-Andean palaeo-records is highlighted. sition of the trade winds originating from the South Pacific Methodological constraints of the chronological precision Subtropical High (SPSH). If the SPSH shifts further equator and the palaeoclimatic interpretation of records derived from wards or loses strength, the polar front in the southeastern different natural archives, such as glacier sediments and ice Pacific might shift further north, leading to winter precipita- cores, lake sediments and palaeo-wetlands, pollen profiles tion in the southern part of the tropical Andes (van Geel et and tree rings are addressed and complementary results con- al., 2000).
    [Show full text]
  • Tropical Climate Changes at Millennial and Orbital Timescales on the Bolivian Altiplano
    University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Earth and Atmospheric Sciences, Department Papers in the Earth and Atmospheric Sciences of 2-8-2001 Tropical Climate Changes at Millennial and Orbital Timescales on the Bolivian Altiplano Paul A. Baker Duke University, [email protected] Catherine A. Rigsby East Carolina University Geoffrey O. Seltzer Syracuse University Sherilyn C. Fritz University of Nebraska-Lincoln, [email protected] Tim K. Lowenstein SUNY Binghamton See next page for additional authors Follow this and additional works at: https://digitalcommons.unl.edu/geosciencefacpub Part of the Earth Sciences Commons Baker, Paul A.; Rigsby, Catherine A.; Seltzer, Geoffrey O.; Fritz, Sherilyn C.; Lowenstein, Tim K.; Bacher, Niklas P.; and Veliz, Carlos, "Tropical Climate Changes at Millennial and Orbital Timescales on the Bolivian Altiplano" (2001). Papers in the Earth and Atmospheric Sciences. 47. https://digitalcommons.unl.edu/geosciencefacpub/47 This Article is brought to you for free and open access by the Earth and Atmospheric Sciences, Department of at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Papers in the Earth and Atmospheric Sciences by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Authors Paul A. Baker, Catherine A. Rigsby, Geoffrey O. Seltzer, Sherilyn C. Fritz, Tim K. Lowenstein, Niklas P. Bacher, and Carlos Veliz This article is available at DigitalCommons@University of Nebraska - Lincoln: https://digitalcommons.unl.edu/ geosciencefacpub/47 Published in Nature 409 (February 8, 2001), pp. 698-701; doi In the summer of 1999 we drilled and continuously cored 10.1038/35055524 Copyright © 2001 Macmillan Magazines Ltd. the Salar de Uyuni to a depth of 220.6 m below the surface.
    [Show full text]
  • Vegetation and Climate Change on the Bolivian Altiplano Between 108,000 and 18,000 Years Ago
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by DigitalCommons@University of Nebraska University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Earth and Atmospheric Sciences, Department Papers in the Earth and Atmospheric Sciences of 1-1-2005 Vegetation and climate change on the Bolivian Altiplano between 108,000 and 18,000 years ago Alex Chepstow-Lusty Florida Institute of Technology, [email protected] Mark B. Bush Florida Institute of Technology Michael R. Frogley Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL Paul A. Baker Duke University, [email protected] Sherilyn C. Fritz University of Nebraska-Lincoln, [email protected] See next page for additional authors Follow this and additional works at: https://digitalcommons.unl.edu/geosciencefacpub Part of the Earth Sciences Commons Chepstow-Lusty, Alex; Bush, Mark B.; Frogley, Michael R.; Baker, Paul A.; Fritz, Sherilyn C.; and Aronson, James, "Vegetation and climate change on the Bolivian Altiplano between 108,000 and 18,000 years ago" (2005). Papers in the Earth and Atmospheric Sciences. 30. https://digitalcommons.unl.edu/geosciencefacpub/30 This Article is brought to you for free and open access by the Earth and Atmospheric Sciences, Department of at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Papers in the Earth and Atmospheric Sciences by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Authors Alex Chepstow-Lusty, Mark B. Bush, Michael R. Frogley, Paul A. Baker, Sherilyn C. Fritz, and James Aronson This article is available at DigitalCommons@University of Nebraska - Lincoln: https://digitalcommons.unl.edu/ geosciencefacpub/30 Published in Quaternary Research 63:1 (January 2005), pp.
    [Show full text]
  • Vegetation and Climate Change on the Bolivian Altiplano Between 108,000 and 18,000 Years Ago
    University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Earth and Atmospheric Sciences, Department Papers in the Earth and Atmospheric Sciences of 1-1-2005 Vegetation and climate change on the Bolivian Altiplano between 108,000 and 18,000 years ago Alex Chepstow-Lusty Florida Institute of Technology, [email protected] Mark B. Bush Florida Institute of Technology Michael R. Frogley Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL Paul A. Baker Duke University, [email protected] Sherilyn C. Fritz University of Nebraska-Lincoln, [email protected] See next page for additional authors Follow this and additional works at: https://digitalcommons.unl.edu/geosciencefacpub Part of the Earth Sciences Commons Chepstow-Lusty, Alex; Bush, Mark B.; Frogley, Michael R.; Baker, Paul A.; Fritz, Sherilyn C.; and Aronson, James, "Vegetation and climate change on the Bolivian Altiplano between 108,000 and 18,000 years ago" (2005). Papers in the Earth and Atmospheric Sciences. 30. https://digitalcommons.unl.edu/geosciencefacpub/30 This Article is brought to you for free and open access by the Earth and Atmospheric Sciences, Department of at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Papers in the Earth and Atmospheric Sciences by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Authors Alex Chepstow-Lusty, Mark B. Bush, Michael R. Frogley, Paul A. Baker, Sherilyn C. Fritz, and James Aronson This article is available at DigitalCommons@University of Nebraska - Lincoln: https://digitalcommons.unl.edu/ geosciencefacpub/30 Published in Quaternary Research 63:1 (January 2005), pp. 90-98; doi:10.1016/j.yqres.2004.09.008 Copyright © 2004 University of Washington; published by Elsevier Inc.
    [Show full text]
  • Lake Titicaca
    Lake Basin Management Initiative Experience and Lessons Learned Brief Lake Titicaca Mario Francisco Revollo Vargas* Maximo Liberman Cruz Alberto Lescano Rivero 1. Description Drought and floods are the natural hazards that have the greatest environmental, social and eco- nomic impact on the Bolivian-Peruvian high plateau (altiplano) which includes the hydrological basin of Lake Titicaca, the Desaguadero River, Lake Poopo and the Salt Lake of Coipasa, collec- tively designated by the acronym TDPS. Through good management, the system can be regulated in benefit of the people who live in the region. Territorial Scope The project area (Figure 1) includes the hydrological basins of Lake Titicaca, the Desaguadero River, and lakes Poopo and Salar de Coipasa (TDPS system). The TDPS system is located in parts of Peru, Bolivia and Chile, spread between latitude 14° 03' to 20° 00' South and between longitude 66° 21' to 71° 07' West. The total area of the system is 143,900 km2 and includes the sub-region Puno in Peru and the departments of La Paz and Oruro in Bolivia. The basins included in the TDPS system have the following characteristics: Lake Titicaca This paper was presented at the Lake Basin Management Initiative 2 Regional Workshop for Europe, Central Asia and the Americas catchment area: 56,270 km 2 held at Saint Michaelʼs College in Vermont, USA, 18-21 June - average lake area: 8,400 km 2003. The workshop was organized by LakeNet in cooperation with SMC and the International Lake Environment Committee medium altitude: 3,810 m above sea level 3 with funding from the Global Environment Facility, U.S.
    [Show full text]
  • Lake Tauca Highstand (Heinrich Stadial 1A) Driven by a Southward Shift of the Bolivian High
    SCIENCE ADVANCES | RESEARCH ARTICLE CLIMATOLOGY Copyright © 2018 The Authors, some Lake Tauca highstand (Heinrich Stadial 1a) driven by a rights reserved; exclusive licensee southward shift of the Bolivian High American Association for the Advancement 1,2 1,3 1 4 1 of Science. No claim to Léo C. P. Martin *, Pierre-Henri Blard *, Jérôme Lavé , Thomas Condom , Mélody Prémaillon , original U.S. Government 5 5 6 1 1 Vincent Jomelli , Daniel Brunstein , Maarten Lupker , Julien Charreau , Véronique Mariotti , Works. Distributed 1 † 1 Bouchaïb Tibari , ASTER Team , Emmanuel Davy under a Creative Commons Attribution Heinrich events are characterized by worldwide climate modifications. Over the Altiplano endorheic basin (high trop- NonCommercial ical Andes), the second half of Heinrich Stadial 1 (HS1a) was coeval with the highstand of the giant paleolake Tauca. License 4.0 (CC BY-NC). However, the atmospheric mechanisms underlying this wet event are still unknown at the regional to global scale. We use cosmic-ray exposure ages of glacial landforms to reconstruct the spatial variability in the equilibrium line altitude of the HS1a Altiplano glaciers. By combining glacier and lake modeling, we reconstruct a precipitation map for the HS1a period. Our results show that paleoprecipitation mainly increased along the Eastern Cordillera, whereas the southwestern region of the basin remained relatively dry. This pattern indicates a southward expansion of the east- erlies, which is interpreted as being a consequence of a southward shift of the Bolivian High. The results provide a new understanding of atmospheric teleconnections during HS1 and of rainfall redistribution in a changing climate. INTRODUCTION tropical Brazil changed in pace with the Heinrich stadials (5, 13–15)and A major uncertainty in our understanding of 21st century climate numerous sites record wetter conditions during these episodes [see concerns the global redistribution of rainfall and modification of mon- compilations (15, 16)].
    [Show full text]
  • Holocene Evolution of Lakes in the Bluefish Basin, Northern Yukon, Canada Bernard Lauriol,1 Denis Lacelle,2 Sylvain Labrecque,3 Claude R
    ARCTIC VOL. 62, NO. 2 (JUNE 2009) P. 212–224 Holocene Evolution of Lakes in the Bluefish Basin, Northern Yukon, Canada BErNard LaurioL,1 Denis Lacelle,2 SylvaiN LaBrecquE,3 CLaudE r. duguaY4 and Alice TELka5 (Received 21 January 2008; accepted in revised form 16 September 2008) aBsTRACT. This study documents the Holocene evolution of lakes located in the Bluefish Basin, northern Yukon, on the basis of lake lithology, distribution of plant macrofossils, and radiocarbon dating of the basal organic material in sediment cores obtained from former lake basins. Basal organic matter from former lake basins is radiocarbon-dated to the late Holocene (< 3770 yr. BP), whereas the 14C ages from the polygonal peat plateaus (~2 m thick) that surround most of the former lake basins cluster in the early Holocene (between 11 435 and 8200 yr. BP). Plant macrofossil distribution in four out of five cores obtained in former lake basins indicates a transition from emergent aquatic vegetation to wetland and terrestrial-type vegetation, suggesting a gradual decline in water levels. The fifth core analyzed for macrofossils showed evidence of sudden lake drainage. The absence of 14C ages from the middle Holocene (7000 to 4000 yr. BP) suggests that the lakes had a greater spatial coverage and water levels during that period, a conclusion supported by the greater surface area occupied by the former lake basins relative to modern lakes and by the fact that the middle Holocene was a wet period in northern Yukon. The gradual decrease in water levels during the late Holocene could be attributed to partial drainage of lakes, increased evaporation under a drier climate, or a combination of both.
    [Show full text]
  • Lake Titicaca
    III. PALEOHYDROLOGY IIL1. A 20,000 years paleohydrological record from Lake Titicaca DENIS WIRRMANN, JEAN-PIERRE YBERT and PHILIPPE MOURGUIART The Bolivian Altiplano is an endorheic basin which extends from 16° to 20° S. Lat. and from 65° to 69°W. Long., with altitudes ranging from 3700 to 4600 metres, covering 200,000 km2 between the Western and Eastern Cordilleras which are 6500 m high (Fig. 1). From north to south, three major lacustrine areas occupy this high plateau: 2 - Lake Titicaca at 3809 metres above sea level, covering 8562 km ; 2 - Lake Poopo at 3686 m.a.s.l. covering 2530 km ; - Coipasa-Uyuni, a group of dry salt lakes, covering 11 ,000 km2 at 3653 m.a.s.l. Over the last 1.8 million years these basins have registered episodes of greatly enlarged lake areas. According to Lavenu et al. (1984) and to Servant and Fontes (1978, 1984), the Pleistocene record of Titicaca lake level fluctu­ ations can be summarised as follows: - during the Early Pleistocene the paleolake Mataro rose with a water level established at 140 metres above the present level. This stage is related to the end of the Calvario glaciation (Servant, 1977) and the corresponding deposits are recognisable mainly at the NW edge of the basin; - the paleolake Cabana occurred during the middle Pleistocene with a water level established at 90 metres above the present Lake Titicaca level: the associated sediments are present on the eastern and western shores of the basin; - then with the retreat of the Sorata glaciation (Servant, 1977) the Ballivian stage occurred with
    [Show full text]