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PRELIMINARY REPORT ON THE TSUNAMI CAUSED BY SISSANO THE EARTHQUAKE AT , WEST SEPIK, PNG ON 17 JULY 1998

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by

International Tsunami Survey Team

September 1998

ABSTRACT The first investigation on the tsunami caused by the earthquake offshore northwestern coast of the Papua New Guinea (PNG) was carried out by the International Tsunami Survey Team (ITST) during the period of 31 July to 7 August 1998. The survey to the damaged area confirmed the 7 - 10 m wave reported and found the place where the waves were larger - up to 15 m and extreme overland flow velocities of 10 to 15m/s. The severe damage and extreme wave heights were confined to a relatively short (30 km) stretch of coast between Aitape and Sissano Villages and specially large along the sandbar the outer margin of Sissano Lagoon.

CONTENTS; Click the following each content to read it 　 1. INTRODUCTION 2. SURVEY TEAM 3. LOCATION OF AITAPE AND DAMAGE 3.1 Geographical Situation of Aitape and Sissano 3.2 History of Aitape 3.3 Recent hazards in PNG 3.4 Casualties 4. TECTONICS AND THE EARTHQUAKE 4.1 Tectonics Backgrounds 4.2 Earthquake of 17 July 1998 5. MEASURED TSUNAMI AND RESULT OF THE SURVEY 5.1 Logistics and Generalities 5.2 Survey Result 5.3 Distribution of Tsunami Runup Heights 5.4 Tsunami observed at each region 6. DISCUSSIONS ON THE TSUNAMI 6.1 Tsunami Magnitude 6.2 Location of tsunami source 6.3 Magnitude of Tsunami Source Estimated By the Linear Theory 7. HYDRAULIC PROPERTIRS OF TSUNAMI 7.1 Relation between Inundation Depth and Current Velocity at Malol 7.2 Relation between Inundation Depth and Degree of Damage to Houses 7.3 Relation between Sand Erosion Depth and Current Velocity 8. PRELIMINARY RECOMMENDATIONS 9. LIST OF MEMBERS 10. REFECERENCES