长白山火山1000年前火山泥流堆积及其灾害

长白山火山１０００年前大喷发，火山泥流堆积物沿松花江中上游分布。距火山较近的是火山泥流的岩屑流堆积，远离火山变为火山泥流的超高密度流堆积。探讨了火山泥流的成因，并指出长白山火山一旦再次爆发，火山泥流将是主要的火山灾害，沿松花江中上游可能造成巨大破坏，并可能危及鸭绿江、图们江中、上游。

LAHAR DEPOSITS OF 1000 a B.P. ERUPTION AT CHANGBAISHAN VOLCANO AND THEIR HAZARDS

The lahar deposits of the 1 000 a B.P. eruption of Changbaishan volcano are distributed along mid-and up part of Songhua river. They are transported for more than 360 km, passing by Jilin city. The lahar deposits accumulated along Erdobaihe valley from 22 km north of volcano down to 83 km north of volcano belong to the debris flow deposits of lahar with maximum width over 5 km and maximum depth over 30 m. Around Liangjiang along Songhua river, 83 km from volcano, the lahar transformed from debris flow to hyperconcentrated streamflow. The hyperconcentrated streamflow deposits with maximum thickness of 11.5 m accumulated along the left bank of Songhua river at Liangjiang. The hyperconcentrated streamflow deposits are composed of rounded pumice, volcanic sand and sedimentary sand with a lot of piece of charcoal.