Büyük Menderes Alçalımı ile Menderes Masifi Yükseliminin Sınırını Oluşturan Kuşağa Uygulanan Bir Deprem Öncesi Çalışması
Büyük Menderes Alçalımı ile Menderes Masifi Yükseliminin Sınırını Oluşturan Kuşağa Uygulanan Bir Deprem Öncesi Çalışması.


Sipahioğlu S.

Özet.


Bu araştırma, Büyük Menderes Alçalımı ile Menderes Masifi Yükseliminin sınırını oluşturan kuşağa uygulanan, bir deprem öncesi çalışmasına yönelik bulunmaktadır. Geçmişin jeoloji ve jeofizik verilerini kullanarak geleceğin deprem etkinliğini belirlemek amacıyla yapılmıştır. Yapılan bu araştırmayla : i) Bölgenin tarihsel depremlerinin sayısı, bugün kataloglarda var olanların % 50'si kadar artmıştır.

ii) Bugün kataloglarda var olan depremlere ait daha ayrıntılı bilgiler elde edilmiştir.

iii) Gerek tarihsel dönem (1900 öncesi) depremlerine ait gözlemsel, gerekse aletsel dönem (1900 sonrası) depremlerine ait aletsel verilere dayanan dış-merkez dağılımlarının bugün var olan faylanmalarının konumlarını tanımlamaya yeterli olmadığı saptanmıştır. Bu nedenle, bölgenin gelecekteki deprem etkinliğini öğrenebilmek icin, jeoloji verilerinin de kullanılmasının, gerekli, olduğu yargısına varılmıştır.

iv) Bölgenin sismotektonik özellikleri belirlenmiştir.

Summary.


This is a pre-earthquake study carried out for the boundary between the uplifted Menderes Massive and the subsided Büyük Menderes River Valley. With this work, it has been; tried to define the future seismic activitiy along the mentioned zone using geological and geophysical data obtained and/or gathered especially for the study. The results obtained from thise research were outlined as follow : i) In the catalogues, there were 28 historical earthquakes occurred before 1900 for the studied area. But, the 14 historical earthquakes were added to the formers by obtaining data from the new sources. Therefore, their total number, increasing 50 %, reached up to 42. ii)This study also brought some additional descriptions for the historical earthquakes which were given in the catalogues. iii)The seismotectonic character of the studied area was outlined as follow : a) The boundary between the uplifted Menderes Massive and the subsided Büyük Menderes River - Valley is the candidate for a higher seismic activity ,in the future. Because, It is a zone , in Which the contrast tectonic movements take place in the present as it was generated in its past continuously.

b) Earthquakes, occurred in the past along this zone having greater intensity values than VIII or magnitude above 6.0, are related with the large surface faultings.

c) These surface faults generally show same peculiarities of Quaternary displacements.

d) Earthquakes which have occurred within this zone, are shallow and their depths of hypo­ center generally vary from 0 to 60 kilometers.

e) Large earthquakes occured within this zone, are related with either the faults which were formed before the events or a new segment were originated by each of large earthquakes.

f) Instrumental data of the earthquakes, occurred between 1913 and 1970, show that most of the were originated in the depths of hypo­ central levels of 40, 0, 10, 3O km respectively

g) This zone will probably show same seismicity pattern in the future as it has shown in its historical times. Because, there isn't any distinctive evidence about the changing in this tectonic regime of its past.

iv) None of the historical and Instrumental epicenter distributaion for the studied area is available to define the current trends of faults. Therefore, geological data must be used necessarily to evaluate the future seismic activity.