SUMMARY

THE EFFECT OF THE FULLMOON AND THE TOTAL SOLAR ECLIPSE ON CRUSTAL DEFORMATION RATE AND AN EARLY DETECTION OF A TSUNAMI-GENERATED-DESTRUCTIVE EARTHQUAKE IN THE SEA OF MARMARA ..
Implication for the Short term Earthquake Prediction:

UĞUR KURAN, Geophysicist (Ret'd)
The Ministry of Public Works & Settlement
General Directorate of Disaster Affairs
Earthquake Research Department,Ankara, TÜRKİYE

The purpose of this paper is to introduce new concepts into the very important field of earthquake prediction and to review some laboratory and field techniques available for detection of a Tsunami–generated-destructive earthquakes at an early stage of development.An unusual Tilt [or strain] transient was recorded about 5 kilometers from the east-west trending NAF zone, where the surface rupture of the 1999 Marmara earthquake occurred and more than 17,000 people were killed.The effect of total solar eclipse on a tsunami- generated- earthquake occurrence and stress/strain[tilt]/time phenomena in Andesite bedrock at Taşburun station before the 17 of August 1999 was discussed.Anomaly was observed at Taşburun recording site which was built in 1984 as part of the joint German-Turkish Earthquake Prediction programme at the western end of the NAF Zone .The present study showed a tilt[or strain] anomaly accompanied a sharp rise[Cyclic–Strain-Softening] in post-eclipse rather than pre-eclipse days.Cyclic–strain-softening[or sharp decrease in Modulus of elasticity of crustal material]can be seen during the course of laboratory fatigue studies on rock speciments just before final failure,during an investigation of Landslide mechanism in the field[İzmir-Yeşildere,Eğridir and Samsun Airpot landslide regions) ,before a rock-burst event which took place in Zigana Highway Tunnel[Trabzon], and also before a tsunami generated destructive earthquake in crustal structure[Taşburnu bore hole tilt station].The detection of a change in a tilt rate[or tidal strain rate] anomaly of this scale associated with a relatively high magnitude[ Mw 7.4] earthquake provides new evidence in the field of earthquake prediction.Clear understanding of the Stress/strain[or tilt]/time phenomena in Taşburun site,may help scientist forecast future earthquakes which provoked large tsunamis and submarine sediment slides at the eastern end of the Marmara Sea in the northwest Turkey .It is important to remember that four days before the 17 th of August 1999 Marmara–Sea Earthquake, twenty-four hours tilt or stair case(saw- cut) type response of daily tidal variation which is combined lunar and solar[luni-solar]force as a result of rotation of the earth on its axis within the moon-sun system was completely lost.This observation which was associated with tilt(or strain- step)is themost important clue about forecasting a destructive earthquake in this region.


AMAÇ

17 Agustos 1999 Kocaeli depremi Izmit yakinlarinda 17km. derinlikte meydana gelmistir. Magnitüd degeri 7.4 olarak saptanmistir. 17.000 den fazla kisi hayatini kaybetmis ve zarar 30 Milyar dolar olmustur. Depremin merkezinden yaklasik 100 km uzaklikta Avcilar yerlesim yeri depremden en fazla etkilenen alanlardan biridir(Tablo-1).

Afet Isleri Genel Müdürlügü (Deprem Arastirma Daire Baskanligi ) ve Avcilar Belediyesi arasinda Avcilar yerlesim yerinin 17 Agustos 1999 depreminden neden daha fazla etkilendigi konusunda hayati öneme haiz bir arastirma programi baslatilmistir.

Mikrobölgelendirme çalismalari; Avcilar Belediyesinde 4 yerbilimcinin, Istanbul Üniversitesi'nden 2 ögretim görevlisinin ve ayrica Istanbul Üniversitesi'nden 7 stajyer ögrencinin, Deprem Arastirma Dairesinden 8 yerbilimcinin, Avcilar Belediyesi ve Afet Isleri Genel Müdürlügü'nün sürekli destek ve yardimlariyla Nisan 2000'den günümüze kadar kesintisiz sürdürülmüstür.

Depremdeki hasar modellerinin belirlenmesiyle zayif noktalar çikartilabilmekte böylece gelecekteki depremlerde zarar en aza indirilebilmektedir. En etkili yöntemler; uygun arazi kullanimi planlarinin olusturulmasi ve gelistirilmesi,binalarin ve diger yapilarin hasar görülebilirliginin saptanmasidir. Mikrobölgeleme deprem tehlikesine uygun olarak yapilan bina düzenlemeleridir. Tablo 1'de gösterilen yapisal hasarlarin yüksek oldugu kesimlerde mikrobölgeleme çalismalari yogunlastirilarak yikima neden olan kritik zemin tasima güçleri, korezyon durumu, zemin büyütmeleri ve zemin hakim peryodlari gibi önemli parametreler elde edilmistir.

Download PDF file