Year-Around Monitoring of Slope Instabilities in Umiammakku Nunaat (Karrat), West Greenland with Deformation Analysis

In June 2017, a large landslide in Umiammakku Nunaat (Karrat), West Greenland caused a huge tsunami wave of about 90 m height on the opposite fjord slope and reached the village of Nuugaatsiaq 32 km far away. The tsunami caused severe property damage and the death of four people in the village. After the tsunami, the two settlements Nuugaatsiaq and Illorsuit were evacuated due to the still high risk of another potential tsunamigenic landslide in the fjord. To this day the two settlements are still under evacuation but none of the villages have been permanently relocated so far.

This disaster highlighted the urgent need for natural hazard monitoring systems in this region. In 2021, Geoprevent and the local responsible authorities made a feasibility study and installed the first ever natural hazard monitoring system in Greenland. This monitoring system in Umiammakku Nunaat runs year-around. Two deformation cameras were installed at the counter slope with a view on three regions of interest. An additional camera was installed next to one of these unstable slopes. These deformation cameras take multiple high-resolution images per day. Cross-correlation based algorithms are then used to identify differences between these images and estimate the deformation of these areas.

A deformation analysis can be compared to a timelapse with which one can see slow processes that a human eye cannot see. The local experts use the information provided by these monitoring systems for a continuous risk assessment. The continuous monitoring helps to evaluate the sitiation constantly and supports authorities in their decision making related to the evacuation of certain settlements.

From a technical point of view, Greenland presents quite some challenges to maintain a monitoring station under these harsh conditions. Remoteness, cold temperatures, heavy winds and polar night are only a few of them. In order to have enough power during polar night, the system is running on a methanol-based fuel cell solution with the option of solar charging during the sunny months. Moreover, communication with the station and the data transmission are satellite-based, so that the station can be controlled remotely.