Remotely Piloted Aircraft System (RPAS) for glaciological studies: case, Pastoruri tropical glacier - Peru

Abstract:

Climate change is accelerating the melting of glaciers in the world. The tropical glaciers are the more susceptible to these climate variations. In Peru, the best-known situation is Pastoruri glacier. This place hosted national and international events for adventure sports. In the last decades, this glacier has been significantly reducing and its conditions do not permitted to practice any sports but the government created a "Climate Change Route" in this zone to visitors from different parts of the world can get to know and evidence the impacts of climate change. Pastoruri glacier is located at an average altitude of ~5074 m.a.s.l. in the region of Ancash, at the coordinates of S -9.9° and W -77.2°.

The objective of the study is to know the glacier mass lost by using RPAS data. Aerial photographs from August and September 2017 were obtained to do a photogrammetric processing the orthophotography and the Digital Surface Model (DSM). The horizontal and vertical corrections and the co-registration (slave and master) were done for the products with a RMS = 3.18 which is below of 4 m (minimum spatial resolution).

The results show a maximum thickness loss of ~29 m/month, average loss of ~3.7 m/month and slopes from 60° to 70° predominantly in the glacier front in contact with the formation lake. However, around glacier front there is a maximum thickness gain of ~30 m/month, where found ice broken and crevasses. The aspect in general is from SW to W predominantly and with slopes from 0.1° to 79°.