Seismic Reflection Survey across the Median Tectonic Line and its 3-D Structure

1992年2月至3月，利用两台可控震机在四国东部的中线构造线(MTL)上进行了长达15.5公里的地震反射调查。在这次地震调查的同时，还进行了重力、大地电磁(MT)和磁力测量。调查结果清楚地表明，MTL向北倾斜30~40度，深度约5.5公里。反射剖面中没有发现超过5.5公里的部分MTL，因为来自深部的信号太弱。在我们调查之前，MTL向北倾斜了30~40度，深度约5.5公里。在我们调查之前，由于来自深部的信号太弱，在反射剖面上没有发现超过5.5公里的MTL部分大多数地质学家认为，MTL必须是从浅到深的垂直方向。因此，我们的结果是革命性的，需要重新审视MTL的形成过程。

15.5-Km-long seismic reflection survey was done by two "Vibroseis" machines across the Median Tectonic Line(MTL),east Shikoku,from February to March in 1992.Accompanied with this seismic survey,gravity,magnetotelluric(MT),magnetic surveys were also made along the seismic survey line.The results from the surveys clearly show that MTL dips northward at 30 to 40 degrees from the ground to about 5.5 km deep.The deeper-than-5.5-km part of MTL has not been found in the reflection profile,because signals from the deeper are too weak.Before our survey, most geologists believe that MTL must be vertical from the shallower to deeper. Therefore our results are revolutionary and they require the re-examination of formative process of MTL.