There largely developed volcano erupting and effusing of the lava from the deep stratum in West Pacific, which provided plentiful sources for the crusts coming into being.
西太平洋由于大规模火山活动存在，深层熔岩上涌，为结壳的形成提供了丰富的物质来源。
2
Water effusing quantity of mine influences of two factors: one is exploitation space of mine, the other is replenishment condition such as precipitation, which is a stochastic factor.
According to domestic and international statistic data, the occurrence probability of gas explosion is not very high, but it occasionally occurs in gas abnormal effusing area of low gas mines.