Abstract ID: 3.10926 | Accepted as Talk | Talk/Oral | TBA | TBA

A jøkulhlaup or Glacier Lake Outburst Flood (GLOF) is a sudden release of water from a glacier lake. In mainland Norway more than 160 GLOF events from 30 glacier lake locations are registered. The water source can be a glacier-dammed lake, a pro-glacial moraine-dammed lake or water stored within, under or on the glacier. One example is Nedre Demmevatn, a glacier dammed lake at the north side of the outlet glacier Rembesdalskåka, Hardangerjøkulen. Catastrophic jøkulhlaups occurred in 1893 og 1937 and led to construction of drainage tunnels to avoid the outburst floods. Since 2014 annual GLOFs have occurred due to the glacier thinning. Repeat glacier lake inventories from satellite data has revealed a growth in glacier lakes in the recent decades due to glacier retreat. About 40 glacier lakes with potential for GLOFs are currently monitored using Sentinel-1 and -2 data. In this study we give an overview of registered GLOF events in Norway and we present ongoing field investigations on Nedre Demmevatnet that are carried out to better understand the processes. We also discuss possibilities for improving standard mapping techniques for glacier lakes. Manual or semi automatic methods are commonly used, often requiring labour-intensive post-processing to improve accuracy. Recent advancements in machine learning offer promising alternatives, enabling more efficient and accurate mapping by integrating multiple input data sources. We present a fully automated workflow, implemented in Google Earth Engine and Python, that is expected to improve the efficiency and reproducibility of glacier lake mapping. A comparison of the results with Norway’s most recent glacier lake inventory from 2018/19 shows further glacier retreat with associated lake expansion and formation of new lakes.