Inventory and geometrical changes in small glaciers covering three Northern Patagonian summits using remote sensing and GIS techniques
In the last few decades, a large quantity of research has been performed to elucidate the current behavior of glaciers in southern Chile, especially with respect to the volumetric changes in the outlets of the Northern and Southern Patagonian Icefields (NPI and SPI, respectively). Calculations have shown a generalized thinning and withdrawal, which greatly contributes to the increase in sea level attributed to the ice melt from non-polar glaciers. However, these icefields are surrounded by many small icecaps, which have yet to be studied in detail. A precise estimation of the volume of ice located in these mountain chains could provide new information with respect to this area’s exact contribution to the increase in sea level. Thus, this study presents an inventory of relatively small Northern Patagonian glaciers in the surrounding of the three summits: Mount Queulat, and the Macá and Hudson volcanoes. The study used remote sensing techniques in a GIS environment to determine the margins, surface areas, thickness changes and hypsometry for the glaciated zones. Landsat images from different dates were analyzed using standard band ratio and screen delineation techniques. Additionally, digital elevation models from different dates were compared using map algebra, calculating thickness changes. Based on the results, we propose that there are important volumetric changes in the glaciers studied, which could be explained by precipitation trends in a general context, and an influence of the glaciers’ sizes in some local response. Therefore, we suggest the exact contribution of the Patagonia to the increase in sea level corresponds to a regional pattern rather than just the behavior of a single ice field.
KeywordsGlacier inventory thickness change digital elevation model morphometric measurement
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- Aniya. M. 2001. Glacier variations of Hielo Patagónico Norte, Chilean Patagonia, since 1944/1945, with special reference to variations between 1995/1996 and 1999/2000. Bulletin of Glaciological Research 18: 55–63.Google Scholar
- Benn, D. and Evans, D. 1998. Glaciers & Glaciation. Arnold.Google Scholar
- Falkner, E. 1995. Aerial mapping. Methods and Applications. CRC Press Inc.Google Scholar
- Fernández, A. 2006. Inventory and Thickness Changes on Corcovado Volcano. Anuario Hidrográfico y Oceanográfico de la Armada de Chile 57: 131–140. (In Spanish).Google Scholar
- Fernández, A., Rivera, A. and Rodrigo C. 2006. Recent Variations of Glaciers Located between 41°S and 49°S and their relationship with climatic changes. Revista Geográfica Panamerican Institute of Geography and History 139: 39–69. (In Spanish).Google Scholar
- Gamache, M. 2004. Free and low cost datasets for international mountain cartography, available at 〈http://www.icc.es/workshop/abstracts/ica_paper_web3.pdf〉 (last access, december 2008).
- Hoelzle, M., Chinn T., Stumm, D., Paul, F., Zemp, M. and Haeberli, W. 2007. The application of glacier inventory data for estimating past climate change effects on mountain glaciers: A comparison between the European Alps and the Southern Alps of New Zealand. Global and Planetary Change 56: 69–82.CrossRefGoogle Scholar
- Kurowski, L. 1891. Die Höhe der Scneegrenze mit besonderer Berücksichtigung der Finsteraarhorne-Gruppe. Penck’s Geographische Abhandlungen 5(1): 119–160.Google Scholar
- Naranjo, J. and Stern, Ch. Holocene explosive activity of Hudson volcano, southern Andes. Bulletin of Volcanology 59: 291–306.Google Scholar
- NIMA, 1997. Department of Defense World Geodetic System 1984: Its Defintions and Relationships with Local Geodetic Systems. NIMA tr8350.2 Third edition 4 july 1997. Bethesda, MD: National Imagery and Mapping Agency.Google Scholar
- Oerlemans, J. 2001. Glaciers and Climate Change. A.A. Balkema publishers.Google Scholar
- Rivera, A., Casassa, G., Acuña, C. and Lange, H. 2000. Recent Variations of Chilean Glaciers. Investigaciones Geográficas 34: 25–52. (In Spanish).Google Scholar
- Rodríguez, E., Morris, Ch., and Belz, J. 2006. A global assessment of the SRTM performance. Photogrammetric Engineering & Remote Sensing 72(3): 249–270.Google Scholar