1977 Yılı Batı Türkiye Deprem Etkinliği
1977 Yılı Batı Türkiye Deprem Etkinliği.


Alsan E., Tezuçan L., Başarır E., Ayhan E., Ulusan N., Üçer S.B.

Özet.


Bu çalışmada 1977 yılı için Batı Türkiye'deki (35° - 42° Kuzey, 25° -32° Doğu) deprem etkinligi incelenmiştir. Ele alınan bölge içindeki depremlerin saptanmasında kullanılan veriler, Kandilli Rasathanesi deprem istasyonları şebekesinin kayıtlarından elde edilmiştir. Depremlerin oluş zamanlarının, episantrlarının ve magnitüdlerinin saptanması Bilgisayar Programı kullanılarak yapılmış ve magnitüdleri 1.9
Summary.


In this study. The earthquake activity in Western Turkey has been investigated during the year of 1977. 1217 earthquakes whese magnitudes were between 1.9 and 5.0 have been observed, those occurred in an area surrounded 35° -42° north latitudes and 25°-32° east longitudes. The data were mainly obtained from the seismic network which is mostly installed in western part of Turkey. The centralseismic station at Kandlli(ISK) in İstanbul has, three components short and long period seismographs together with Wood-Anderson Torsion seismographs . All permenant stations in Anatolia were equipped by high gain, short period, vertical component Geotech Seismograph System. The data have been processed by computer. Since there was no clear information abent seismic velocities and the crustal structure in western part of Anatoli, Herrin’s travel-time tables for the depths 0.15 and 49 km. have been used in the computation. These tables are not sufficient to obtain the true fecal depths. Therefore, the depths have not been included in lists containing the earthquake parameters. However, Herrin’s travel-time tables give reliable results for the epicenter determinations. Signal duration on the records of seismic stations have been used in magnitude calculations and the average values of the magnitudes were given in the lists. The earthquake activity in Western Turkey is given as a list including the following information: date of earthquake (day, month, year) origine time (GMT) geographical estimates of, epicenters, magnitudes, root mean square of residuals (RMS), number of arrivals and solution quality respectively. On the other hand, Epicentre Maps were drawn by plotter to reflect the earthquake activity in Western Turkey. In these maps the earthquakes have been ploted according to their magnitudes and quality of the solutions. In monthly results the epicentres are classified depending upon the solution quality, such as good (A), fair (B) and poor (C). The same repre- sentation is valid for the quarterly maps but here, the poor solution are excluded, as the map showing the annual activity only the good solutions are given. During the year or 1977, the main activity was the earthquake swarm near to Emet town where activity has started in May, 1976. Besides some local activities were observed in West Anatolia, such as : İzmir-Manisa, Gökova Bay, Marmara Sea, Saros Bay, Aydın -Kuşadası Sisam, Yalova - Çınarcık, Savaştepe - Sındırgı, Denizli -Tefenni activities.