Geodetic Mass Balance of Haxilegen Glacier No. 51, Eastern Tien Shan, from 1964 to 2018

The eastern Tien Shan hosts substantial mid-latitude glaciers, but in situ glacier mass balance records are extremely sparse. Haxilegen Glacier No. 51 (eastern Shan, China) is one of the very few well-measured and comprehensive glaciological measurements were implemented from 1999 to 2011 re-established 2017. Mass (1999–2015) has recently been reported, record not extended period before 1999. Here, we used a 1:50,000-scale topographic map long-range terrestrial laser scanning (TLS) data calculate area, volume, changes for 1964 2018. lost 0.34 km2 (at rate 0.006 a−1 or 0.42% a−1) its area during 1964–2018. experienced clearly negative surface elevation geodetic balance. Thinning occurred almost across entire surface, with mean value −0.43 ± 0.12 m a−1. calculated average was −0.36 w.e. Without considering error bounds estimates, loss over past 50 years line observed modeled (−0.37 0.22 that published short time intervals since slightly less than Shan. Our results indicate Riegl VZ®-6000 TLS can be widely unmonitored individual glaciers.