IANIGLA   20881
INSTITUTO ARGENTINO DE NIVOLOGIA, GLACIOLOGIA Y CIENCIAS AMBIENTALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
IDENTIFICATION AND MONITORING OF ROCK GLACIER UNITS (31°-33°S)
Autor/es:
CARLA TAPIA BALDIS; JÁNOS MÉSZÁROS; SEBASTIÁN RUIZ PEREIRA; MARTÍN MENDOZA; ENEKO BERIAIN URBE; DARIO TROMBOTTO LIAUDAT
Lugar:
Wellington
Reunión:
Congreso; SouthCOP, Queenstown, 2019; 2019
Resumen:
?Monos de Agua? catchment islocated at 33°S; 70°16W in the Juncal sub-basin (Central Andes, Chile). In thelast 60 years, it lost a 27±3% of glacierized surface. A ratio of covered/uncovered glaciers in the sub-basin is of 24%. Several rock glacier geoformswere mapped and represent 8.18km2within Juncal sub-basin.Nowadays, above 3600m ASL, ?Monosde Agua? catchment presents several rock glacier deposits and surfacesubsidence throughout the valley as well as ice-cored moraines in the lesssun-exposed slopes. Further, with a mean annual air temperature of -2 ± 2°C andhaving >100 freeze-thaw cycles per year, the upper-catchment is assumed asbeing affected by permafrost occurrence. At the ?Monos de Agua? catchment,a sub-metric DEM was obtained (Fig. 1a) by aerial photography which resemblesthe same geoform as in 1955 (Hycon aerial image, 1m resolution), withoutnoticeable changes in motion or edges. Results point-out that a critical frozenvolume may be present in mountain catchments at determined circumstances in theform of rock glacier flows which coalesce with moraines and solifluction lobes.Such sources may configure a part of the basin?s input yet not in the currentand projected water budgets.In the Argentinian Central Andes,the active layer of ?Candidato? rock glacier (Fig. 1b) is monitored since March2018. SMT100 soil temperature and volumetric water content, as well as iButtonsDS1922L temperature sensors, where installed at 0; 25; 50 and 70 cm depth. Soildensity, porosity, moisture, bulk thermal conductivity, thermal diffusivity,heat capacity and latent heat where calculated from in situ soil samples, inthree trenches above 4000 m ASL. Results indicate that moisturesaturation in the active layer reached up to 40% at 50 cm depth, after thedelayed winter snow precipitation during year 2018 and, during the first monthsof the warm season (November-December). Since January to July, the uppermostsoil levels of the active layer remain almost dry (5-15% moisture) (Figure 1c).First findings support updatedwater-resource baselines for future legislations and water-planning in waterscarce region of developing countries.