Suhora Technologies satellite data show Bhutan's Sintaphu Tsho lake lost 73% of its area after GLOF

The Hindu Sci-Tech reported on November 5, 2026 that a near-real-time satellite assessment by Suhora Technologies, a Noida-based geospatial intelligence company, found a 73% reduction in the surface area of Sintaphu Tsho. The Himalayan glacial lake in Bhutan's Gasa district was hit by a glacial lake outburst flood (GLOF) on October 29. thehindu.comThe Hindu Sci-Techthehindu.comOpen source ↗ The adjoining supraglacial lake shrank by 24.4%. thehindu.comThe Hindu Sci-Techthehindu.comOpen source ↗

A supraglacial lake is a temporary body of meltwater that collects in surface depressions on a glacier or ice sheet. Sintaphu Tsho lies at about 14,700 feet above mean sea level. According to the assessment, it lost the most water during the outburst. thehindu.comThe Hindu Sci-Techthehindu.comOpen source ↗

Sintaphu Tsho: ten years of imagery

The company analysed late-October satellite imagery from 2016 to 2026. Before the flood, Sintaphu Tsho was stable, gaining 3.4% in surface area, from 23.33 ha in 2016 to 24.13 ha in 2026. The gain peaked on October 28, the day before the outburst. thehindu.comThe Hindu Sci-Techthehindu.comOpen source ↗

After the GLOF, the lake's surface area fell to 6.54 ha, down 73%. That is less than a third of its size at any point in the previous ten years. thehindu.comThe Hindu Sci-Techthehindu.comOpen source ↗

Supraglacial lake and the consequences of the flood

The neighbouring supraglacial lake grew steadily over the same decade, from 5.74 ha to 16.51 ha, an increase of 188%, nearly three times its 2016 size. It added about 1.1 ha a year, with no year of shrinkage. After the GLOF it fell to 12.47 ha, down 24%, but it remains more than twice its 2016 size. thehindu.comThe Hindu Sci-Techthehindu.comOpen source ↗

Sintaphu Tsho lies below Wakila Mountain in the Lungo area of Laya Gewog, an administrative block. The October 29 flood from this lake destroyed facilities at Gasa Tshachu, a popular natural hot spring on the banks of the Mo Chhu River. It also triggered flash flood warnings for parts of West Bengal and Assam. thehindu.comThe Hindu Sci-Techthehindu.comOpen source ↗

Krishanu Acharya, co-founder of Suhora Technologies, said the findings highlight the importance of continuous monitoring of glacial lake systems and the role of satellite-based Earth observation in understanding changes across vulnerable Himalayan terrain. thehindu.comThe Hindu Sci-Techthehindu.comOpen source ↗