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Articles 1 - 8 of 8

Full-Text Articles in Physical and Environmental Geography

Initial Limnology Of Laguna Pozo Verde, Costa Rica: Bathymetry, Water, Sediments, And Diatoms, Sally P Horn, Erik N. Johanson, Mauricio Murillo Herrera, Kurt A. Haberyan, Taber Friedel, Chad S. Lane Dec 2023

Initial Limnology Of Laguna Pozo Verde, Costa Rica: Bathymetry, Water, Sediments, And Diatoms, Sally P Horn, Erik N. Johanson, Mauricio Murillo Herrera, Kurt A. Haberyan, Taber Friedel, Chad S. Lane

Geography Publications and Other Works

ABSTRACT. Introduction: Costa Rica has hundreds of lakes, many of which have never been scientifically studied. Objective: To carry out a first, basic limnological study of Laguna Pozo Verde in Juan Castro Blanco National Park, Costa Rica (~1935m elevation), to provide baseline data for studying future changes. Methods: We measured water depths and temperatures, and Secchi depth; analyzed surface sediments; and examined maps and satellite imagery. Results: Though described by some as formed by volcanic processes, Laguna Pozo Verde likely formed in a landslide, which occur frequently in this rainy area on the steep south slope of the inactive Porvenir …


Mapping Glacial Landforms On The Chiripó Massif, Costa Rica, Based On Google Earth, A Digital Elevation Model, And Field Observations, Yingkui Li, Taylor Tieche, Sally P. Horn, Yanan Li, Renrong Chen, Kenneth H. Orvis Jan 2019

Mapping Glacial Landforms On The Chiripó Massif, Costa Rica, Based On Google Earth, A Digital Elevation Model, And Field Observations, Yingkui Li, Taylor Tieche, Sally P. Horn, Yanan Li, Renrong Chen, Kenneth H. Orvis

Geography Publications and Other Works

The Chirripó massif in the Cordillera de Talamanca, Costa Rica, is one of a few sites in Central America that preserve evidence of past glaciation. We mapped glacial landforms in this area using Google Earth high-resolution imagery and a 30 m Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM). Prior field observations, field notes, photographs, and landform maps were used to check and refine the delineated landform boundaries. The composited map includes lateral and terminal moraines, tills, glacial valleys, glacial lakes, nunataks, arêtes, and horns. Glacial extents during three proposed stages were mapped in the Valle de las Morrenas, …


Initial Limnological Observations At Five Small Lakes In Southern Pacific Costa Rica, Sally P Horn, Erik N. Johanson, Kurt A. Haberyan, Mathew S. Boehm, Jessie L. Johanson, Maureen Sánchez P., Mario Hernández V. Jun 2018

Initial Limnological Observations At Five Small Lakes In Southern Pacific Costa Rica, Sally P Horn, Erik N. Johanson, Kurt A. Haberyan, Mathew S. Boehm, Jessie L. Johanson, Maureen Sánchez P., Mario Hernández V.

Geography Publications and Other Works

Costa Rica has hundreds of lakes, many of which have never been described or sampled by limnologists. Here we summarize initial observations of five small (0.2–1.7ha) lakes located at low elevation (365–490m) in the cantón of Buenos Aries. We collected basic limnological data and samples during visits in 2013 and 2014, and compiled environmental and archaeological data for their surroundings as a contribution to the documentation of lake diversity in Costa Rica, and to support parallel investigations of indicators of environmental history preserved in the sediments of the lakes. Lagunas Carse, Los Mangos, Danta, and Ojo de Agua all appear …


Methods For The Study Of Soil Charcoal As An Indicator Of Fire And Forest History In The Appalachian Region, U.S.A., Sally P Horn, Christopher A. Underwood Jan 2014

Methods For The Study Of Soil Charcoal As An Indicator Of Fire And Forest History In The Appalachian Region, U.S.A., Sally P Horn, Christopher A. Underwood

Geography Publications and Other Works

Charcoal particles in soils and sediments of the Appalachian region provide evidence of long-term fire history relevant to resource management and to studies of paleoclimate, vegetation history, and the effects of prehistoric and historic humans on the environment. Charcoal records of fire history are of low resolution in comparison to dendrochronological records, but reach well beyond the oldest trees in most areas, providing evidence of fires thousands or tens of thousands of years ago. We focus here on fire history reconstruction from soil charcoal, which provides site-specific evidence of past fires and potentially forest composition. Charcoal > 2 mm may be …


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 Jan 2005

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 Jan 2005

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 Jan 2005

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 Mar 2002

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 …