贡嘎山海螺沟冰川冰舌地段的泥石流

Debris Flow in the Ice Tongue Area of Hailuogou Glacier on the Eastern Slope of Mt.Gongga

海螺沟冰川冰舌地段1976年以来发生过两次大的冰雪雨水泥石流。1989年7月8日和26日观景台西沟的泥石流通过1.7km长的冰面后,在冰川末端前形成一个5.5×10~4m^3的扇形地;1976年8月长草坝3号冰川下部冰碛体边坡的两处滑坡泥石流在开阔地上扩散堆积后,达1317.8m^3/s的泥石流和洪水下到冰川上。今后每年雨季还有可能发生更大规模的泥石流,值得人们警惕。

Two large debris flows caused by ice-snow meltwater and rainfall have occurred on both southern and northern sides of the ice tongue of Hailuogou Glacier in the distance of 5 km from the large icefall at an elevation of 3 720 m on the eastern slope of Mt. Gongga since 1976. In front of the glacier tongue, a fan with about 5.5 × 104m3 material formed by two ice-snow meltwater and rainfall debris flows occurred on the 8th and 26th of July, 1989, in the Guanjingtaixigou. The debris flows carried the superglacial till away, broke the ice-body, cut a ditch with 1.2 km long on the northern side of the Hailuogou Gl., and also made the subglacial river change the way. In Aug., 1976, two sliding debris flows occurred at the moraine fringes, more than 200 m in the relative height, of No. 3 Glacier of Changcaoba, southern side of Hailuogou Gl.. Their occurrence results from the buried ice melted, ice-snow meltwater, rainfall and earthquake etc. According to the influence factors of climate warming, glacier retreating, ice-body thinning, frequent avalanche occurring, melt till increasing, buried ice melting, steep and high moraine unstabilizing, fluid precipitation increasing and earthquake affecting, authors declare that the larger scale of ice-snow meltwater and rainfall debris flow may occur again in the ice tongue sector of Hailuogou Glacier from now on. This will have influence on the action of tourism, climbing and scientific exploration etc. in some degree in the rainy season (June to Aug.) of every year, people should keep vigilant over occurrence of a large calamity.