Portal de Periódicos da CAPES

Glaciar Jorge Montt (Chilean Patagonia) dynamics derived from photos obtained by fixed cameras and satellite image feature tracking

2012; Cambridge University Press; Volume: 53; Issue: 60 Linguagem: Inglês

10.3189/2012aog60a152

1727-5644

Andrés Rivera, Javier G. Corripio, Claudio Bravo, Sebastián Cisternas,

Arctic and Antarctic ice dynamics

Abstract Tidewater calving glaciers can undergo large fluctuations not necessarily in direct response to climate, but rather owing to complex ice–water interactions at the glacier termini. One example of this process in Chilean Patagonia is Glaciar Jorge Montt, where two cameras were installed in February 2010, collecting up to four glacier photographs per day, until they were recovered on 22 January 2011. Ice velocities were derived from feature tracking of the geo-referenced photos, yielding a mean value of 13 ±4 md –1 for the whole lower part of the glacier. These velocities were compared to satellite-imagery-derived feature tracking obtained in February 2010, resulting in similar values. During the operational period of the cameras, the glacier continued to retreat (1 km), experiencing one of the highest calving fluxes ever recorded in Patagonia (2.4 km 3 a –1 ). Comparison with previous data also revealed ice acceleration in recent years. These very high velocities are clearly a response to enhanced glacier calving activity into a deep water fjord.