Open Access. Powered by Scholars. Published by Universities.®
Physical and Environmental Geography Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Publication
- Publication Type
Articles 1 - 7 of 7
Full-Text Articles in Physical and Environmental Geography
Establishing A Chronology Of Late Quaternary Glacial Advances In The Cordillera De Talamanca, Costa Rica, Rebecca Susan Potter
Establishing A Chronology Of Late Quaternary Glacial Advances In The Cordillera De Talamanca, Costa Rica, Rebecca Susan Potter
Masters Theses
Little research has focused on glacial events in the tropics. Providing an absolute glacial chronology in Costa Rica will build a foundation for future glacial chronologies and paleoclimate reconstructions in the highlands of Central America. Evidence of past glaciation, including moraines and glacial lakes, is preserved within formerly glaciated valleys in the Cordillera de Talamanca. Orvis and Horn (2000) constrained deglaciation ages of the most recent glacial event in the Cordillera de Talamanca based on radiocarbon dates of glacial lake sediments. Radiocarbon ages indicated complete deglaciation after 12.4 ka cal BP but before 9.7 ka cal BP (Orvis and Horn, …
Stable Isotope Analysis Of Lake Sediments From Laguna Santa Elena And Laguna Azul, Costa Rica, Matthew Timothy Kerr
Stable Isotope Analysis Of Lake Sediments From Laguna Santa Elena And Laguna Azul, Costa Rica, Matthew Timothy Kerr
Masters Theses
Lake sediments are increasingly important archives of human-environment interactions and paleoclimate in the neotropics. In Costa Rica, Anchukaitis and Horn (Palaeogeography, Palaeoclimatology, Palaeoecology 221: 35–54, 2005) established a land-use history for Laguna Santa Elena (8.9306 N, 82.9275 W, 1055 m elevation), a small lake in the Diquís archaeological region, based on pollen and charcoal analyses of a 7-meter sediment core. I carried out stable carbon and nitrogen isotope and loss-on-ignition analyses at higher resolution to extend the existing 2000-year record. The new geochemical data parallel major trends in botanical proxies but also reveal aspects of human and environmental dynamics …
Spatial Variation In Organic Carbon And Stable Isotope Composition Of Lake Sediments At Laguna Zoncho, Costa Rica, Zachary P Taylor
Spatial Variation In Organic Carbon And Stable Isotope Composition Of Lake Sediments At Laguna Zoncho, Costa Rica, Zachary P Taylor
Doctoral Dissertations
Lake sediments are valuable paleoenvironmental archives that provide information on past climate and land-use change. Most lake sediment studies rely on a single core, usually recovered from the center of a lake, and do not consider spatial variability in the lake basin. My dissertation presents a spatially-explicit record of prehistoric agriculture from Laguna Zoncho, Costa Rica and evaluates spatial variability in lake sediment proxies based on a network of five sediment cores. Results extend earlier proxy analyses of a single core collected near the center of the lake, which documented prehistoric agriculture and forest clearance from 3000 to about 500 …
Limnología De Las Lagunas Glaciales En El Páramo Del Chirripó, Costa Rica. (Limnology Of Glacial Lakes In The Chirripó Páramo Of Costa Rica.), Sally P Horn, Kenneth H. Orvis, Kurt A. Haberyan
Limnología De Las Lagunas Glaciales En El Páramo Del Chirripó, Costa Rica. (Limnology Of Glacial Lakes In The Chirripó Páramo Of Costa Rica.), Sally P Horn, Kenneth H. Orvis, Kurt A. Haberyan
Geography Publications and Other Works
More than 30 lakes of glacial origin exist within the Chirripó páramo in the Cordillera de Talamanca of Costa Rica. This chapter describes the geomorphic setting and physical and chemical limnology of 19 lakes located between 3450-3570 m elevation in the upper basins of five glaciated valleys. All lakes are clear, dilute, and apparently polymictic. Water chemistry data from 1998, 2000, and 2001 are similar from lake to lake and year to year, and are consistent with sparse prior measurements between 1966 and 1991. However, the lake water temperatures we have measured are much higher than those reported by earlier …
Dinámica De La Vegetación Después De Fuegos Recientes En Los Páramos De Buenavista Y Chirripó, Costa Rica (Vegetation Dynamics Following Recent Fires In The Buenavista And Chirripó Páramos Of Costa Rica), Sally P Horn
Geography Publications and Other Works
Field studies following fires in the Buenavista (La Muerte Massif) and Chirripó páramos demonstrate that woody species show varying responses to fire. The bamboo Chusquea subtessellata and the ericaceous shrubs Vaccinium consanguineum and Pernettya prostrata typically resprout vigorously after fire, but rarely if ever recolonize burn sites by seeding. The shrub Hypericum irazuense, in contrast, generally suffers high mortality in páramo fires, but successfully reestablishes by seed following all but the largest fires. Preexisting vegetation, fire characteristics, and site differences both before and after burning likely affect rates of shrub and herb survival, colonization, and growth in páramo burn …
Registros De Sedimentos Lacustres De La Vegetación Del Holoceno Y Historia Del Fuego En El Páramo De Costa Rica. (Lake-Sediment Records Of Holocene Vegetation And Fire History In The Costa Rican Páramos), Sally P Horn, Brandon L. League
Registros De Sedimentos Lacustres De La Vegetación Del Holoceno Y Historia Del Fuego En El Páramo De Costa Rica. (Lake-Sediment Records Of Holocene Vegetation And Fire History In The Costa Rican Páramos), Sally P Horn, Brandon L. League
Geography Publications and Other Works
We examined pollen, pteridophyte (ferns and fern-allies) spores, and charcoal in a 5.6 m long sediment core from Lago de las Morrenas 1, and charcoal in a 1.1 m long sediment core from Lago Chirripó, to reconstruct postglacial vegetation and fire history in the Chirripó páramo. Lago de las Morrenas 1, the largest lake in the Valle de las Morrenas of Chirripó National Park, is presently surrounded by treeless páramo vegetation and has apparently been so since deglaciation approximately 10,000 radiocarbon years ago. Pollen spectra suggest no pronounced changes in vegetation since ice retreat. Pollen percentages for Gramineae and other …
Gps Locations And Costa Rican Topo Maps, Kenneth H. Orvis
Gps Locations And Costa Rican Topo Maps, Kenneth H. Orvis
Geography Publications and Other Works
Over the past several years I have been working with Sally Horn and our U.S. and Costa Rican collaborators on several projects in Costa Rica related to paleoenvironmental research. Such research requires accurately locating geomorphic and archaeological features in the field, using GPS and the 1:50,000 scale topographic maps produced by the Instituto Geográfico Nacional. Doing so is a challenge to the uninitiated, because GPS locations (including elevation) appear to be just plain wrong when you match them to the map. A position collected on the north side of a stream plots on the south side on the map, or …