图  1   本文所用地震台站及剖面位置分布示意图

黑色三角形为本文中所使用的固定台站； 4条红色直线为共转换点(common converted point，简写为CCP)剖面，青色倒三角形为其中心位置；红色三角形为长白山火山； 十字形为P_660s的穿透点位置； 白色虚线为俯冲板块等深线(引自Gudmundsson， Sambrige，1988)

Figure  1.   Distribution of the seismic stations and locations of the profiles

Black triangles denote the permanent seismic stations used in this study.The red lines with its names on the side denote the locations of four CCP profiles and the cyan inverted triangles are their midpoints.The red triangle shows the location of the Changbaishan volcano.The crosses denote piercing pointsof P_660s.The white dashed lines are the depth contours of the subduction slab (after Gudmundsson,Sambrige,1988)

图  2   远震事件分布图

Figure  2.   Distribution of the teleseismic events used in this study

图  3   CCP叠加剖面图

红色倒三角形表示分布在距剖面30 km范围内的地震台站;黑点表示发生在剖面两侧各50 km范围内的深震事件位置

Figure  3.   Common conversion point images for the four CCP profiles

The red inverted triangles show the stations within 30 km away from the profile.The horizontal direction denotes distance along profile with its midpoint as 0 km,and the vertical direction denotes depth in the profile.The black dots denote the deep seismic events located 50 km away from the profile; the depths of 410 km and 660 km are indicated as two dashed lines,respectively

图  4   660 km间断面三维表面图

Figure  4.   The 3D surface of the 660 km discontinuity

图  5   由共转换点剖面得到的各剖面地幔过渡带厚度图

3条虚线分别代表地幔过渡带260， 250和240 km厚度位置

Figure  5.   The thickness of the mantle transition zones obtained from the corresponding CCP profiles

The three dash-lines denote the thickness of the 260 km， 250 km， 240 km， respectively