Brief communication: Glaciers in the Hunza catchment (Karakoram) have been nearly in balance since the 1970s

Previous geodetic estimates of mass changes in the Karakoram revealed balanced budgets or a possible slight mass gain since similar to 2000. Indications of longer-term stability exist but only very few mass budget analyses are available before 2000. Here, based on 1973 Hexagon KH-9, similar to 2009 ASTER and the SRTM DTM, we show that glaciers in the Hunza River basin (central Karakoram) were on average in balance or showed slight insignificant mass loss within the period similar to 1973-2009. Heterogeneous behaviour and frequent surge activities were also characteristic of the period before 2000. Surge-type and non-surge-type glaciers showed on average no significantly different mass change values. However, some individual glacier mass change rates differed significantly for the periods before and after similar to 2000.