Surface change over two months, at a 95% level of detection.

M3C2 surface change analysis between 2 July and 15 September 2017, draped on the July model. The analysis highlights many commonly occurring proglacial processes, such as backwasting, mass movements and dead-ice melt.

• See the forefield in September 2017

Histogram of values. Positive values (red) indicate negative change.

The 95% confidence threshold was calculated using local surface roughness and a registration error of 16.1 cm.

• July model: 120 semi-vertical drone images.
• September model: 82 oblique and 159 semi-vertical drone images.

Registration was done using 16 common points, and was included in the SfM bundle adjustment of the July model.