Farecast of Seismic Activity in the North Aratolian fault

土耳其北方的北安纳托利亚断裂带由于存在着所谓的地震空区而被认为是地震预报研究的试验场。本研究的目的是通过地震学研究来探讨地震发生的特征及其与被认为将来在差距地区发生的大地震的关系。此外，还在差距地区连续测量了地磁场和大地电磁场，以发现异常并阐明其机制。(1)地震观测为了监测差距地区的微震活动，我们建立了一个无线电连接的地震观测系统，该系统由一个基站和五个卫星站组成，基站上安装了一个三分量地震仪，卫星站上安装了一个垂直分量地震仪。观测发现，在差距地区有微震发生，但微震活动的探测水平较低。 ...更多信息 还是不够。所以我们现在正在安装更多的车站。(2)应变测量在差距区域中非常靠近活动断层的一个测站安装了一台精密应变仪，以监测与断层位移相关的可能应变变化。然而，安装深度太浅，无法摆脱温度效应，必须对观测数据进行处理，以消除这种影响。(3)地磁和大地测量七个地磁和两个大地测量站已经在运行，以监测研究区与地震有关的地磁场和大地场的可能变化。到目前为止，我们已经获得了一些与小地震有关的大地电磁场异常变化的例子。(4)震源过程的研究我们分析了土耳其20多个地震的记录，详细阐明了震源过程与构造的关系。特别是发现1967年穆杜尔努河谷东震震源过程复杂，总体上可表现为走滑机制，但在其西端却发现了正断层成分，这有望为穆杜尔努河谷地震震源区以西的差距地区大震的孕育过程提供线索。少

The North Anatolian fault zone in northern Turkey has been considered to be a test field for earthquake prediction studies, because there exists a so-called seismic gap. The purpose of this research is to investigate the characteristics of earthquake generation through seismic studies and their relation to a large earthquake which has been considered to occur in the gap area in the future. In addition, continuous measurements of the geomagnetic and telluric fields have been made in the gap area to detect anomalies and clarify their mechanisms.(1) Seismic observationIn order to monitor microseismic activity in the gap area, we have established a radio-linked seismic observation system consisting of a base station, where a three-component seismometer was set up, and five saztellite stations, where a vertical-component seismometer was installed. It was found from the observations that some microearthquakes have been occurring in the gap area, but the detection level for microseismicity tu … More rned out to be still insufficient. So we are now installing a few more stations.(2) Strain measurementA precise strainmeter was installed at a station located very close to an active fault in the gap area to monitor a possible strain change associated with fault displacement. However, the installation depth turned out to be too shallow to escape from the temperature effect and the observed data must be processed so as to remove this effect.(3) Geomasgnetic and telluric measurementsSeven geomagnetic and two telluric stations have been in operation to monitor possible changes in the geomagnetic and telluric fields associated with earth quakes in the study area. So far we have obtained some examples of anomalous changes in the telluric field associated with some rather small earthquakes.(4) Study of earthquake source processWe have analyzed seismic records of more than twenty events in Turkey, and detailed earthquake source processes have benn clarified in relation to tectonics. In particular, it was found that the 1967 Mudurnu Valley easrthquake has a complicated source process, this earthquake can be characterized generally by a strike-slip mechanism, but at its western end the normal-fault constituent was found. This is expected to provide a clue to the generation process of a large earthquake in the gap area, that is the west of the source area of the Mudurnu Valley earthquake. Less