Science The reasons and consequences of the 2023 GLOF that occurred on October 4th in Sikkim, India. Bella Brown October 26, 2023 The author of The Landslide Blog is Dave Petley, a renowned expert in the field of landslide research and control. The ever-reliable Save the Hills blog has a fascinating post about the impact of the 4 October 2023 Glacial Lake Outburst Flood (GLOF) in Sikkim, India. The lead author on the blog, Retired Wing Commander Praful Rao, travelled down the Teesta river, which was the path of the GLOF, documenting the damage. He has posted an invaluable photographic record to the Save the Hills blog. There is huge richness in his report, but I will highlight two elements. First, the level of damage is very high. This image, for example, shows river sediment left by the flood:- The aftermath of the GLOF (Glacial Lake Outburst Flood) that occurred on October 4, 2023 in the Teesta valley of India. The image was captured by Praful Rao and shared on the Save the Hills blog. According to Praful’s caption: Chand Adhikari, an employee of an IRCON contractor, resided in this leased residence with 12 other co-workers. He is currently standing in what was once their dining room. The GLOF disaster has covered everything and they have been advised against digging for safety concerns over potential army explosives hidden in the debris. This is a truly tragic and unacceptable situation. Furthermore, the recent flood has caused destabilization of the river slopes due to toe erosion, which will result in long-term issues. Praful has provided an image that illustrates this persistent problem – according to the local population, slope movement is still occurring. The infrastructure of Tessta Bazaar was likely damaged due to slope movement following the 4 October 2023 GLOF in Sikkim. An image captured by Praful Rao and shared on the save the Hills blog shows the aftermath. Dan Shugar from the University of Calgary in Canada first brought attention to the problem of landslides occurring on the Teesta River following the GLOF event. There have been around twelve minor landslides into the Kambara River in Papua New Guinea, including one larger one that was caused by recent earthquakes. Other minor landslides have also occurred in nearby rivers, but there have not been any major ones observed. @planet pic.twitter.com/osroTEYbqR — Dan Shugar (@WaterSHEDLab) October 9, 2023 In the meantime, a potential landslide barrier on the Teesta River has been recognized by Ashim Sattar from IIT Bhubaneswar in India. #sikkimflood #newlake At a distance of 30 kilometers from the South Lhonak lake, a landslide caused by a GLOF has obstructed the river’s path, resulting in the formation of a new lake that has been damaged by the landslide. The lake has partially drained through a channel beneath the debris, but it still remains. — Ashim Sattar (@GlacierHazards) October 21, 2023 Efforts are ongoing to comprehend the factors behind the GLOF. It is very likely that a landslide into the glacial lake was the catalyst, leading to overflow. Unfortunately, there is strong evidence indicating that the slope is still causing issues. During the weekend, @planet satellites captured images of increased landslides on the South Lhonak Lake moraine in Sikkim, India. This is expected due to the presence of streams along the moraine, which could be causing the slopes to become saturated and weaker. These events are being closely monitored under the hashtags #teestariver and #GLOF. The images can be viewed at this link: https://t.co/VPUEoy8SIJ. — Dan Shugar (@WaterSHEDLab) October 16, 2023 Surveillance is necessary at this location. Go back to the homepage of The Landslide Blog. This text is protected by © 2023. The authors have licensed it under CC BY-NC-ND 3.0. Unless otherwise stated, images are protected by copyright. It is prohibited to use them without explicit permission from the owner of the copyright.