270 likes | 290 Views
Overview of cryospheric phenomena in South America with focus on glaciers, permafrost, snow hydrology, and environmental regulations. Includes key data on glacier changes in the region.
E N D
Status of cryospheric observations in South America Gino Casassa Geoestudios & University of Magallanes Chile GLOBAL CYOSPHERE WATCH GCW
Latin American Cryosphere • “White” Glaciers: National Agencies, GTNH, Research Institutions • <GLOFs - jokulhlaups, glacier slides, ice avalanches> • Rock Glaciers: Mining companies, Research Institutions, National Agencies (starting) • Permafrost: Mining companies, Research Institutions (Darío Trombotto, IANIGLA, Mendoza) • Snow Hydrology: National Agencies, Research Institutions, Water & Hydroelectric Companies • Snow Avalanches: National Agencies, Research Institutions, Mining companies • Lake & River Ice: No active research/monitoring
RECENT INCREASE OF ENVIRONMENTAL REGULATIONS RELATED TO GLACIERS • 2006. CHILE FREEZES GLACIER LAW. • 2009. CHILE approves “Glacier Policy”, with a glacier definition that has no lower limit on size, and which accepts a glacier as an ice mass having no flow. • Even small snowfields can now be considered as glaciers. • 2010. CHILE modifies Environmental Impact Assessment (EIA) law, now includes glaciers. • 2012. ARGENTINA approves Glacier Law, includes as well “periglacial environment with hydrological significance”. • 2013. CHILE. Changes to EIA. Glacier drilling now needed.
A) “WHITE” GLACIERS “Clean Glacier”: all surface debris free. Glaciar Olivares Alfa Glaciar del Paine Grande, Magallanes Glaciar Olivares Gama, sub-subcuenca Olivares. “Covered Glacier”: partly covered by debris. Geoestudios, 2013 Glaciar San Francisco, subcuenca Alto Maipo.
ROCK GLACIER Flujo Glaciar Pedregoso, cuenca Río Aconcagua Geoestudios, 2013 Zanja de exploración en glaciar Monolito, que fluye de derecha a izquierda. Bandas oscuras en el hielo son planos de cizalle en la Zona de Ablación (zona de compresión). • Cubierta de detritos: Espesor 0,3 a 3,3 m de gravas angulosas. Conductividad térmica 0,20 a 0,26 (media 0,217) W/mK • Núcleo de hielo: Espesor >40 m. 78% a 82% promedio de hielo, resto detritos rocosos, principalmente en bandas. • Morrena basal: 50% hielo, 50% detritos rocosos. Espesor, algunos metros.
GLACIERS IN SOUTH AMERICA: ~28,000 km2 (~10% of all mountain glaciers) *excluding glaciers in Antarctic Peninsula & Greenland PATAGONIAN ICEFIELDS: NPI ~4,000 km2; SPI ~12,500 km2. TOTAL ~16,500 km2, ~60% in area of all South American glaciers area Global Glacier Changes: facts and figures, UNEP-WGMS, 2009
GLACIERS in SOUTH AMERICA Casassa, VICC 2010
Bahr et al. (1997): V = 0,025*A^γ where A: Area V: volume γ = 1.37 for valley glaciers γ = 1.25 for ice caps Casassa, VICC 2010
México: only 2 mountains are glacier-covered, with a reduction of more than 20% in the last 50 years • Venezuela: 87% glacier loss during the last 50 years • Colombia: 2-5% annual retreat during the last 10 years • Ecuador: glacier reduction of 27% in 1997-2006 • Peru, Cordillera Blanca: in 1970-2008 glacier reduction >26% • Chile & Argentina, northern sector: starting in 1980 glaciers (monitored since 1970) have incremented their retreat; glaciers in central and southern Chile and Argentina are losing ice, many times in an accelerated rate, with only a few cases of stable & advancing glaciers
10th Meeting Latin American Snow and Ice Working Group UNESCO IHP 14-18 November 2011, , Mérida, Venezuela 2012: NOVEMBER MEETING OF GTNH in CUZCO, Peru 2013: QUITO, Ecuador
SNOW ROUTES North of Chile Pascua Lama
Gerd Dercon Laboratory Head, Soil and Water Management & Crop Nutrition Laboratory, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture (Technical Officer)
STATION/HUT SUB-GREY, TORRES DEL PAINE NATIONAL PARK