Accession Number : AD0284910

Title :   THE NATURE OF TSUNAMIS. THEIR GENERATION AND DISPERSION IN WATER OF FINITE DEPTH

Corporate Author : NATIONAL ENGINEERING SCIENCE CO PASADENA CALIF

Personal Author(s) : WILSON,BASIL W. ; WEBB,LOIS M. ; HENDRICKSON,JAMES A.

Report Date : AUG 1962

Pagination or Media Count : 1

Abstract : Original contains color plates: All ASTIA reproductions will be in black and white. Original may be seen in ASTIA Hq. DESCRIPTORS: *Seismic waves, *Ocean bottom, Earthquakes, Classification, Hazards, Inten sity, Geological survey, Northern hemisphere, Southern hemisphere. Identifiers: Tsunamis, Tidal waves. Current knowledge on important characteristics of tsunamis and their modes of generation isASSEMBLED. A review of seismic source mechanisms discloses that evidence is in favor of molar upthrusting or down-drop of the sea-bed, over an extensive fault-line or bottom area, being the principal mode by which dangerous tsunamis are generated. Submarine landsliding and volcanic eruption in open water are likely to be less effective mechanisms, though underwater slumping in confined areas such as bays or channels and as. Noteworthy tsunamis are unlikely to result from earthquakes of magnitude less than M = 6.4 (Richter scale). Dangerous tsunamis may be expected when M exceeds about 7.75. Laws of wave height decay and period increase with distance are established on theoretical and experimental grounds. (Author)

Descriptors :   *OCEAN BOTTOM, *SEISMIC WAVES, CLASSIFICATION, EARTHQUAKES, GEOLOGICAL SURVEY, HAZARDS, INTENSITY, NORTHERN HEMISPHERE, SOUTHERN HEMISPHERE

Distribution Statement : APPROVED FOR PUBLIC RELEASE