Accession Number : AD0493400

Title :   SEISMIC WAVES FROM HELGOLAND BLAST OF 18 APRIL 1947. PART II,

Corporate Author : NAVAL ORDNANCE LAB WHITE OAK MD

Personal Author(s) : Pomerantz, J. ; Perkins, B., Jr. ; Atanasoff, J. V. ; Bonwit, K. S.

Report Date : 22 NOV 1948

Pagination or Media Count : 12

Abstract : This portion of the report discusses horizontal earth displacements caused by the Helgoland blast and includes the calibration curves for the seismograms presented in Part I. The displacements at the earth's surface due to the longitudinal and transverse waves through the granitic layer decreased as the 1.23 and 2.52 powers of distance respectively. Earth displacements due to the longitudinal and transverse waves that traveled below the earth's crust decreased as the 2.11 and 2.25 powers of distance respectively. The maximum amplitudes registered on the seismometers that recorded the longitudinal component of the earth's motion decreased as the 2.80 power of distance; the maximum amplitudes registered for transverse components of earth displacement decreased as the 2.41 power. (Author)

Descriptors :   (*SEISMIC WAVES, EXPLOSION EFFECTS), HIGH EXPLOSIVE AMMUNITION, NORTH SEA, BLAST, EPICENTERS, EARTHQUAKES, WEST GERMANY, GRANITE, RANGE(DISTANCE), CALIBRATION.

Subject Categories : Explosions

Distribution Statement : APPROVED FOR PUBLIC RELEASE