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Mapping Glacial Landforms on the Chiripó Massif, Costa Rica, Based on Google Earth, a Digital Elevation Model, and Field Observations

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Mapping Glacial Landforms on the Chiripó Massif, Costa Rica, Based on Google Earth, a Digital Elevation Model, and Field Observations University of Tennessee, Knoxville Trace: Tennessee Research and Creative Exchange Geography Publications and Other Works Geography 2019 Mapping Glacial Landforms on the Chiripó massif, Costa Rica, Based on Google Earth, a Digital Elevation Model, and Field Observations Yingkui Li [email protected] Taylor Tieche [email protected] Sally P. Horn [email protected] Yanan Li [email protected] Renrong Chen [email protected] See next page for additional authors Follow this and additional works at: https://trace.tennessee.edu/utk_geogpubs Part of the Physical and Environmental Geography Commons Recommended Citation Li, Y., Tieche, T., Horn, S.P., Li, Y., Chen, R., and Orvis, K.H. 2019. Mapping Glacial Landforms on the Chiripó massif, Costa Rica, Based on Google Earth, a Digital Elevation Model, and Field Observations. Revista Geológica de America Central 60: 109–121. doi: 10.15517/rgac.v2019i60.36465 This Article is brought to you for free and open access by the Geography at Trace: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Geography Publications and Other Works by an authorized administrator of Trace: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. Authors Yingkui Li, Taylor Tieche, Sally P. Horn, Yanan Li, Renrong Chen, and Kenneth H. Orvis This article is available at Trace: Tennessee Research and Creative Exchange: https://trace.tennessee.edu/ utk_geogpubs/28 Revista Geológica de América Central, 60, 109-121, 2019 doi: 10.15517/rgac.v2019i60.36465 ISSN: 0256-7024 MAPPING GLACIAL LANDFORMS ON THE CHIRRIPÓ MASSIF, COSTA RICA, BASED ON GOOGLE EARTH, A DIGITAL ELEVATION MODEL, AND FIELD OBSERVATIONS MAPEO DE TIERRAS GLACIALES EN EL MACIZO DEL CHIRRIPO, COSTA RICA, BASADO EN GOOGLE EARTH, UN MODELO DE ELEVACIÓN DIGITAL, Y OBSERVACIONES DE CAMPO Yingkui Li1, Taylor Tieche1, Sally P. Horn1*, Yanan Li1†, Renrong Chen1‡ and Kenneth H. Orvis1 1Department of Geography, University of Tennessee, Knoxville, TN 37996, USA; [email protected]; [email protected]; [email protected]; [email protected] †Current address: Department of Geography, Texas State University, San Marcos, TX 78666, USA; [email protected] ‡Current address: School of Geography and Tourism, Jiaying University, Meizhou 514015, China; [email protected] *Author for correspondence: [email protected]; Tel.: +1-865-974-6030 (Recibido: 07/25/2018; aceptado: 11/17/2018) ABSTRACT: 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 observa- tions, 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, a major north-facing va- lley on the massif, based on previous reconstructions. The mapped glacial features cover roughly 22.1 km2, representing the minimum extent of the rnaximum glaciation during the Last Glacial Maximum (LGM). This refined map provides an important dataset to help reconstruct Quaternary climate change in this tropical highland. Keywords Glacial landforms, Chirripó massif, Google Earth, SRTM DEM, Cordillera de Talamanca. Li, Y., Tieche, T., Horn, S. P., Li, Y., Chen, R and Orvis, K. H. (2019). Mapping glacial landforms on the Chirripó massif, Costa Rica, based on Google Earth, a digital elevation model, and field observations.Revista Geológica de América Central, 60, 109- 121. doi: 10.15517/rgac.v2019i60.36465 110 REVISTA GEOLÓGICA DE AMÉRICA CENTRAL RESUMEN: El macizo de Chirripó en la Cordillera de Talamanca, Costa Rica, es uno de los pocos sitios en América Central que conserva evidencia de glaciación en el pasado. Mapeamos formas de relieve glaciales en esta área usando imágenes de alta resolución de Google Earth y un modelo de elevación digital (DEM) de la Misión Topográfica de Ra- dar Shuttle de 30 m. Observaciones previamentes de campo, notas de campo, fotografías y mapas de formas de relieve se usaron para verificar y refinar los límites del relieve delineados. El mapa compuesto incluye morrenas laterales y terminales, laderas, valles glaciares, lagos glaciales, nunataks, arêtes, y cuernos. Las extensiones glaciales durante tres etapas propuestas se mapearon en el Valle de las Morrenas, un importante valle orientado hacia el norte en el macizo, basado en reconstrucciones previas. Las características glaciales mapeadas cubren aproximadamente 22,1 km2, que representan la extensión mínima de la glaciación máxima durante el período del último glacial máximo (LGM). Este mapa refinado proporciona un importante conjunto de datos para ayudar a reconstruir el cambio climático del Cuater- nario en este altiplano tropical. Palabras clave: Formas de relieve glacial, Macizo de Chirripó, Google Earth, modelo de elevación digital SRTM, Cordillera de Talamanca. INTRODUCTION Barquero & Ellenberg, 1986; Orvis & Horn, 2000; Lachniet & Seltzer, 2002; Lachniet et al., 2005). For Reconstructing past fluctuations of tropical gla- example, Orvis and Horn (2000) provided detailed ciers has garnered significant attention in recent de- maps and glacier reconstructions for the Valle de cades (Seltzer, 2001; Smith et al. 2005; Licciardi et las Morrenas, and Lachniet and Seltzer (2002) and al. 2009; Jomelli et al. 2014). Compared to the gla- Lachniet et al. (2005) mapped the overall glacial ciers in the middle and high latitudes, tropical gla- landform distribution, including moraines, tills, and ciers have distinctive mass balance characteristics the maximum glacial extent, for the entire Chirripó due to the relative constancy of mean daily tempera- massif. However, the quality and accuracy of these ture: all-year ablation on the lower parts of glaciers landform interpretations and maps are limited by the and cyclical accumulation affected by the migration resolution of the topographic maps and by the num- of the Intertropical Convergence Zone (Kaser & ber of field sites that could be visited and checked by Osmaston, 2002; Benn et al. 2005). Investigating the the investigators. In addition, the mapped glacial fea- pattern of past glaciations in tropical mountains is of tures were likely overgeneralized and some features critical importance for understanding trends in tropi- mapped by different investigators were not exactly cal paleoclimate and their forcing mechanisms. In matched in detail. the Cordillera de Talamanca of Central America, gla- The availability of digital elevation models cial landforms left behind by past glaciers record the (DEMs) and high-resolution satellite images (such as extent and timing of glacial fluctuations associated sub-meter to meter resolution DigitalGlobe or CNES/ with Quaternary climate change (Hastenrath, 1973, Astrium imagery available in Google Earth) provide 2009; Bergoeing, 1977; Barquero & Ellenberg, a unique opportunity to map glacial landforms in re- 1986; Wunsch et al., 1999; Orvis & Horn, 2000; mote areas. With these new datasets and advanced Lachniet & Seltzer, 2002; Lachniet, 2004, 2007; techniques in geographic information systems (GIS), Lachniet & Vazquez-Selem, 2005; Lachniet et al., new efforts to map glacial landforms have been car- 2005; Castillo-Muñoz, 2010). Detailed mapping of ried out in various highlands of the world, such as the these landforms would provide an important dataset Tibetan Plateau, Tian Shan, and other Central Asian to help reconstruct paleoclimate and environmental mountains (e.g. Heyman et al., 2008; Morén et al., change in this tropical highland. 2011; Fu et al., 2012; Stroeven et al., 2013; Blomdin Previous studies of glacial geomorphology in et al., 2016; Chen et al., 2016; Li et al., 2016). These the Cordillera de Talamanca of Central America have mapping efforts have significantly improved our un- focused mainly on the Chirripó massif. Glacial land- derstanding of the extent of past glacial fluctuations. forms in this area have been described in the forms However, no work of this kind using high-resolution of field notes, photos, and landform interpretations satellite images in Google Earth and recently updat- and maps based on available topographic maps and ed DEMs has been published for the Cordillera de air photographs (Hastenrath, 1973; Bergoeing, 1977; Talamanca of Central America. Revista Geológica de América Central, 60, 109-121, 2019 / ISSN: 0256-7024 Li et al.: Mapping glacial landforms on the Chirripó... 111 We mapped glacial landforms on the Chirripó published literature (Orvis & Horn, 2000; Lachniet massif of the Cordillera de Talamanca where land- & Seltzer, 2001, Lachniet, 2004, Lachniet et al. form field descriptions, photos, and age constraints 2005) to validate and refine the delineated landform are available (Hastenrath, 1973, 2009; Orvis & Horn, boundaries. Our updated map provides a framework 2000; Lachniet & Seltzer, 2002; Lachniet, 2004, to reconstruct the pattern of past glacial fluctuations 2007; Lachniet & Vazquez-Selem, 2005; Lachniet et in this key tropical mountain area. It also provides al. 2005). Glacial landforms were mainly identified a resource for future studies of soils and vegetation and delineated in Google Earth with the sub-meter on the massif, and may assist
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