Butara is the 5th largest and longest glacier in the world outside the polar region. It is 57 meters long and occupies an area of 285 sq km. Batura glacier is in the Batura Valley of Passu Gojal, a village in upper Hunza. Residing in the north of Batura Muztagh, which is a sub-range of Karakorum, the glacier is the main source of water in the Hunza river that merges into the Gilgit river eventually making its way to the Indus River. According to the Copernicus Sentinel-2 mission carried out by European Space Agency in August 2021, the Batura glacier is stable and expanding in contrast to the global shrinkage of glaciers. The mission reveals that the glacier retreating is less than the global average. This peculiar and anomalous behavior of the region’s glacier is called ‘Karakoram Anomaly’ (European Space Agency , 2022). In a paper published in 2022 in the American Metrological Society’s Journal Society Journal of Climate, the revival of western disturbances is causing the Karakorum anomaly. Western disturbances are the extreme rainfall events originating from Caspian and the Mediterranean Sea that occur during the winter in the Karakorum region. Western disturbance is an important source of moisture as it contains 65% of the seasonal snowfall volume and 53% of the seasonal precipitations. As a result, moisture prevents the glaciers from climate change and shrinking (Aaquib Javed, 2022).
Batura comprises two parts. The upper part contains pure ice while the lower portion mostly features grey sea stone and moraine. Moraine is the deposition of rocks and sediments driven by Avalanches. Because of the rough terrain and other challenges in the Karakorum region, it is challenging to conduct frequent and accurate field studies which leads to limited long-term ground observational data on the Batura glacier. The GIS remote sensing of the Batura glacier for the last decades indicates that the glacier retreating is not linear, but it is fluctuating following a non-linear trend. According to GIS maps, the glacier advanced significantly from 2000-2005. From 2005 to 2010, the glacier experienced retreating. From 2010 to 2015, the pattern repeats itself, and the glacier again advanced. However, the glacier did not show any changes between 2015 to 2020.
References
Aaquib Javed, P. K. (2022). Does the Recent Revival of Western Disturbances Govern the Karakoram Anomaly? American Metrological Society, 4383–4402.
European Space Agency. (2022, 02 04). Retrieved from Earth From Space: Batura Glacier : https://www.esa.int/Applications/Observing_the_Earth/Copernicus/Earth_from_Space_Batura_Glacier
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