Historical beacon fire lines as early warning systems for glacier lake outbursts in the Hindu Kush–Karakoram Mountains

Abstract

The paper presents a historical long-distance communication system based on beacon fires in one of the most dynamic and rugged mountain ranges of the world, the Hindu Kush-Karakoram-Himalayas. It was deployed as an early warning system for glacial lake outburst floods, which caused devastating impacts on settlement zones and infrastructure until the middle of the twentieth century. The study revealed that the beacon fire systems were operated in distinct valleys spread over the entire Hindu Kush-Karakoram Region. The remarkable fact is the establishment of fire posts in highly difficult accessible mountain environments with communication distances of several hundred kilometres for individual beacon lines. The warning system was a cooperative natural hazard management, which was operated even across distinct ethnic groups. Distant societies, formerly perceived as isolated villages by physical barriers of the high mountain relief, were in historical times connected not only by challenging trade routes but also by a fast working optical communication system. The findings are discussed in the context of a future sustainable natural hazard management.Keywords Beacon fire • Early warning system • Glacial lake outbursts • Local knowledge • Sustainable natural hazard management • Hindu Kush-Karakoram '…and now I watch for the light, the signal-fire breaking out of Troy, shouting "Troy is taken"'.Watchman in Aeschylus (458 B.C.)

Cryosphere hazards in Ladakh: the 2014 Gya glacial lake outburst flood and its implications for risk assessment

“…On 6 August 2014, a glacial lake outburst flood (GLOF) hit the village of Gya (33° 39′ N, 77° 44′ E) in Ladakh. GLOF events are not a new phenomenon in the upper Indus basin: a number of such events have been reported from the Karakoram and Western Himalaya dating back to the nineteenth century (Hewitt 1982;Hewitt and Liu 2010;Iturrizaga 2019). Large and recurrent GLOF events happened in the Shyok and Nubra valley, where the river was blocked by a glacier several times during the nineteenth century, followed by destructive outburst floods (Bhambri et al 2019(Bhambri et al , 2020Cunningham 1854;Sheikh 2015;Sinclair 1929).…”