Nordmannsjøkelen, mainland Europe’s northernmost glacier, has fragmented into small remnants, with only one unit showing signs of active ice flow. The glacier has lost 92% of its area since 1970 (September 2024 area relative to 1970 area). It is reduced from 23.5 km2, as an upper bound of its size in ∼1900, to 0.4 ± 0.08 km2 in September 2024. Between 1970 and 2020, the geodetic mass balance was −17.6 ± 1.79 m w.e., corresponding to an average annual mass balance of –0.35 ± 0.04 m w.e. a−1. The warm summer of 2024 took its toll on Nordmannsjøkelen and the glacier area was reduced by 1.08 ± 0.16 km2 from 2023 to 0.4 ± 0.08 km2 in 2024 (a 68% reduction relative to 2023 area). Similar glacier retreat and thinning are observed elsewhere in the region, and the neighboring Langfjordjøkelen has mass balance measurements for the period 1989–2024, and the highest mass loss is recorded in 2024.

Glacier mass balance is a key variable for the monitoring strategies of the Earth climate system, but the continuation of long-term observations is now endangered by the impending extinction of several monitored glaciers. It is therefore advisable to start new observations on neighbouring glaciers that are more likely to survive into the next few decades. These glaciers will be located at higher altitude, have larger elevation range, thus preserving an accumulation area and have good spatial representativeness. Glaciers with these characteristics may pose some problems and are more demanding for mass-balance measurements and calculations, due to their size and presence of remote and inaccessible areas, further complicated by the complex morphology and high-lateral gradients of mass balance. I present the new mass-balance series for La Mare Glacier, started in 2003 to replace the long-term monitored and rapidly vanishing Careser Glacier in the Ortles-Cevedale Group (Eastern Italian Alps). Direct glaciological mass-balance observations have been complemented by measurements with the hydrological method and, as recommended by the World Glacier Monitoring Service, validated using the geodetic method. The collected data are useful for testing and optimising two techniques proposed in the literature for extrapolating measurements to inaccessible areas.