Publication Date:
2020-07-23
Description:
Microseism recordings from four European broadband stations and from three seismic
arrays in Scotland, Norway, and Germany are compared with model wave data of the
oceanic wave field in the North Atlantic and local ocean wave data from the Norwegian
coast at 60�N, both measured during February–March 2000. Two approaches have been
tested to locate generation areas of microseismic energy: a new amplitude correlation
technique and beam backprojection from the three seismic arrays. Both techniques reveal
that the main generation areas are located in specific regions off the coast of Southwest
Norway and North Scotland. Seismic stations distant from these generation areas record a
superposition of seismic energy from different source regions. Those close to a specific
source region also show a high correlation with it. Both techniques give upper limits for
the extent of the generation area of the strongest storm on 6/7 March at the southwest
Norwegian coast of about 500 km. By using marine X-band radar measurements of the
two-dimensional wave height spectrum, we estimate that the relative change of the
extension of the generation area off the coast of southwest Norway during several storms
is less than a factor of 3. This indicates that the size of the generation area is controlled by
static features as coastline or bathymetry, and not by the extent of the storms. Microseism
energy appears to be mainly controlled by the wave height in distinct and identifiable
generation regions, so that the wave climate in these regions can be studied using historical records of microseisms.
Type:
Article
,
PeerReviewed
Format:
text
DOI:
10.1029/2002JB002338
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