Norwegian Fringes

The animation, which is based on an interferogram generated with two radar images captured by Sentinel-1A in ‘Interferometric Wide-Swath’ mode on 11 and 23 August 2014, mainly shows topography around the northern coast of Norway. Although Sentinel-1A is still being commissioned, this new result demonstrates how useful it will be to map the shape of the land and monitor ground movement. Synthetic aperture radar interferometry – or InSAR – is a technique where two or more satellite radar images acquired over the same area are combined to map topography and detect surface changes. Small changes on the ground cause changes in the radar signal phase and lead to the rainbow-colored fringes of an ‘interferogram’. In this case, the animation denotes differences in topography.

Since the area around the Lyngen Alps is particularly prone to landslides, it is closely monitored. Large landslides that suddenly shift rock into the sea could potentially create tsunami-like waves. In 1810, such a wave destroyed a village, and, history shows that this kind of natural disaster occurs a couple of times every 100 years in Norway. InSAR is an important tool used by the Norwegian authorities to map rockslide hazards nationwide. The unprecedented coverage offered by the Sentinel-1 mission will significantly increase the value of InSAR data for this purpose.

Video credit: Copernicus data (2014)/ESA/Norut–SEOM Insarap study (video animation data: Norwegian Mapping Authority and NASA)

Note: For more information, see Norway Relief. For similar images, one featuring northwestern Italy and part of Corsica and the other featuring Mount Etna on the island of Sicily, see New Views From Sentinel-1A and Etna Slopes, respectively.