关键词: 南北地震带, 反演方法, 磁性层, 地震活动

Abstract: An equivalent model of the bottom of magnetic layer and a two-dimensional inversion method with variable magnetic inclination in polar coordinate system are developed in this paper. By using the model and method,the structure of the magnetic layer and its relation to seismicity in North-South Seismic Belt are discussed in detail on the basis of the magnetic data in the region. The following conclusions can be drawn from the result:1. Both the northern and southern parts of the magnetic layer in the belt are thicker than the central part with their demarcati,on lines through 28癗 and 34癗,respectively;2. The bottom of the magnetic layer appears as a N-S-trending broad uplift zone in an area from 100癊 to 106癊,getting shallower from south to north,with its shallowest part at 103癊;3. The P,T condition of the magnetic,layer is suitable for the accumulation of stress energy,and thus the magnetic layer is a seismogenic layer. Most of the earthquakes occurred within the magnetic layer,especially in the transition zone from its thick to thin parts. The seismicity is usually accompanied by faulting,hot spring and magmatism.

Key words: North-South Seismic Belt, Inversion method, Magnetic layar, Seismicity