Multidisciplinary Research on Fault Activity in the Western Part of the North Anatolian Fault Zone (The Second Phase)

本研究的目的是研究北安那托利亚断裂带西部的断层活动性。首先，我们进行了地震观测，以检查所谓的地震间隙区的微地震活动。3个月来9个台站的观测结果表明，南段地震活动非常少，而北段地震活动比较多。为了揭示大地震的复发率，我们还进行了一次沟探工作。事实证明，大地震每300-400年发生一次。与日本的活动断层相比，这个速度非常短。地貌学工作还划定了一条活动断层的延伸范围，迄今为止，这条断层一直很模糊。电、磁工作揭示了与断层结构有关的异常，并在此基础上对7个台站的地磁场进行了连续测量。到目前为止，似乎已经发现了与地震能量轻微增加有关的轻微异常变化。在断层附近也进行了连续的电测量。在活动断层附近的一些地点，对土壤气体中的氡浓度进行了常规监测。我们把这些结果汇编成一份报告。自从我们在地震预测的国际会议上报告了结果以来，我们被要求将这份报告的副本发送给世界各地的科学家。

The aim of this research is to investigate fault activity in the western part of the North Anatolian Fault Zone. First we made seismic observations to examine microseismic activity in the so-called seismic gap area. The result of observations at 9 stations during three months indicates that seismic activity is very low at the southern section, whereas activity is high in the northern section. We also made a trenching work in order to reveal the recurrence rate of major earthquakes. It turned out that major earthquakes occur every 300-400 years. This rate is extremely short compared with active faults in Japan. Geomorphological work also delincated the extension of an active fault which has so far been vague. Electric and magnctic work disclosed anomalies associated with fault structure and based on the anomalies, continuous measurements of the geomagnetic field has been made at 7 stations. So far slight anomalous changes seem to have been detected in association with slight increase in seismic energy. Continuous electric measurements have also been made in the vicinity of the fault. Radon concentration in soil gas has been monitored routinely at some sites near the active fault. We complied these results in a report. We have been requested to send copies of this report to scientists over the world since we reported the results at an international meeting on earthquake prediction.