Journal of Natural Disaster Science

Preliminary Report on the 17 August 1999 Kocaeli Earthquake, Turkey

Ken SUDO, Muneo HORI, Toshihiko SUGAI, and Kimiro MEGURO
University of Tokyo
Minehiro NISHIYAMA, Yasuhiro UMEDA
Kyoto University
Masato MOTOSAKA
Tohoku University
Yoshihiro KINUGASA
Tokyo Institute of Technology
Atsushi TANAKA
Bunkyo University
Ikki NAKABAYASHI
Tokyo Metropolitan University
Kenji KOSA
Kyushu Institute of Technology
and
Shin'ichiro MORI
Ehime University

(Received 21 October, 1999 and in revised form 15 November, 1999)

Abstract

In the early morning of 17 August 1999, a devastating earthquake with Magnitude 7.4 on the Richter scale occurred beneath Izmit City, Kocaeli Province, Turkey. The destruction to Turkish nation was severe both in casualties and economic damage. Seven large earthquakes occurred along the North Anatolian Fault in the 20th century since 1939, the epicenters migrating westward. The earthquake of 1967 took place 70 km east of the Kocaeli earthquake site. Taking the westward migration of the epicenters into consideration, people involved in earthquakes disaster management in Turkey had anticipated this earthquake to occur at a site closer to Istanbul soon after the event of 1967.

The Monbusho, the Japanese Ministry of Education, Science, Culture and Sports, dispatched a survey team to investigate the Kocaeli disaster and to learn lessons from the disaster. Activities of this team were (1) observation of the fault system which this earthquake formed; (2) estimation of how strongly ground close to the fault was shaken during the event; (3) investigation of structural damage and its relation to earthquake motion; (4) estimation of ground motion at sites at which no instrument recording was made; and (5) investigation of the management of the disaster and the societal response to it.

Key words

Kocaeli Earthquake, North Anatolian Fault, pancake collapse, urban earthquake disaster, land deformation