Spectral Properties and Source Areas of Storm Microseisms at NORSAR

Spectral estimates from eight microseismic storms recorded by long period vertical component seismometers at NORSAR exhibit distinct spectral peaks in the bands 50-85 mHz and 110-195 mHz. A high frequency third peak (180-250 mHz) is also resolvable in some cases. High resolution frequency wave-numbe...

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Bibliographic Details
Main Authors: Korhonen, H, Pirhonen, S E
Other Authors: ROYAL NORWEGIAN COUNCIL FOR SCIENTIFIC AND INDUSTRIAL RESEARCH KJELLER
Format: Text
Language:English
Published: 1976
Subjects:
Seismology
Seismic Detection and Detectors
*MICROSEISMS
*SEISMIC DATA
*SEISMIC DETECTION
ESTIMATES
HIGH FREQUENCY
METEOROLOGICAL DATA
NORTH ATLANTIC OCEAN
NORWAY
NORWEGIAN SEA
POWER SPECTRA
SEISMOMETERS
SOURCES
SPECTRUM ANALYSIS
STORMS
VERY HIGH FREQUENCY
NORWEGIAN SEISMIC ARRAY
LONG PERIOD SEISMOMETERS
Norway
Norwegian Sea
North Atlantic
Online Access:http://www.dtic.mil/docs/citations/ADA021450
http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA021450
Description
Summary:Spectral estimates from eight microseismic storms recorded by long period vertical component seismometers at NORSAR exhibit distinct spectral peaks in the bands 50-85 mHz and 110-195 mHz. A high frequency third peak (180-250 mHz) is also resolvable in some cases. High resolution frequency wave-number analysis of the storm microseisms yield azimuthal estimates which are accordant with meteorological disturbances over both the North Atlantic Ocean and the Norwegian Sea. The early stages of a typical storm development are characterized by a relatively concentrated microseismic source area to the west of NORSAR, whereas later on the source area expands and new sources appear to the NW and to the north of NORSAR. Simultaneously the spectral peaks migrate towards higher frequencies. Prepared in cooperation with Oulu Univ. (Finland). Dept. of Geophysics, and Helsinki Univ. (Finland). Inst. of Seismology.

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