通过简要介绍火山区不同压力源模型引起的垂直形变与水平形变特征,总结不同模型引起的最大水平位移与最大垂直位移的比值R,得到膨胀模型产生的地表形变多以中心为对称,R小于0.5;腔状模型产生的地表形变多为轴对称,可得到更高的R比值;这些结论为模拟分析火山区压力源参数选用模型时提供依据。最后利用所得结果,分析了长白山天池火山可能的压力源模型。可知2002—2003年天池火山区地表变形形状及变化量接近点源模型;而2003—2004年点位形变变化比较复杂,可能由于火山岩浆活动减弱以及复杂的介质环境引起。
The characteristics of the vertical and horizontal deformation caused by different pressure source models are introduced.Then the ratio R for different models of maximum horizontal to maximum vertical displacement is summarized.The results show the surface deformations of the dilatational models are centrosymmetric and R is less than 0.5;However the surface deformations of the cavity models are axisymmetric and R is larger.The conclusions provide the basis for choosing appropriate models when we simulate the pressure source parameters.Finally,the source models are analyzed in Changbaishan Tianchi volcano by using the results obtained.It is shown that the Mogi model is applicable to the deformation between 2002 and 2003,but the deformation is irregular during 2003~2004,which maybe owing to the volcanic activity is weakened and the environment is complex.