Detailed studies of the low to intermediate seismicity in two coastal
regions of Norway have been used in a comparison between earthquake
locations from local high-precision networks on the one side and
locations using a sparse regional array network on the other side.
To this end, a reference set of 32 low-magnitude earthquakes have
been located using two local temporary networks in northern and western
Norway, with estimated epicenter accuracies better than 5 and 10
km, respectively. Comparisons are made between the local network
solutions and the NORSAR Generalized Beamforming (GBF) system, which
provides automatic phase association and location estimates using
the Fennoscandian regional array network. The median automatic GBF
location error is of the order of 20-30 km when four or more arrays
detect the event, increasing to about 80-100 km when only two arrays
are available, and the automatic GBF bulletin is essentially complete
down to magnitude ML = 2.0. Most of the mislocation vectors of the
NORSAR GBF solutions are oriented perpendicular to the Norwegian
coast, and with a tendency to pull the location in a southeasternly
direction. The GBF performance is clearly better, both in terms of
accuracy and completeness, than the performance of the automatic
bulletin of the Prototype International Data Center (PIDC) which
uses data from essentially the same network. The analyst reviewed
NORSAR and PIDC bulletins show, not unexpectedly, an improvement
in location accuracy compared to the automatic solutions and appear
to be of similar quality for the few common events, with an average
mislocation of about 20ukm. The NORSAR reviewed bulletin is more
complete at low magnitudes compared to PIDC, and there appears to
be a potential for significant improvements in the PIDC processing
of small seismic events in this region.
%0 Journal Article
%1 hicks_etal:2001
%A Hicks, E. C.
%A Bungum, H.
%A Ringdal, F.
%D 2001
%I Birkhäuser Basel
%J Pure and Applied Geophysics
%K geophysics seismology
%N 1-2
%P 129--141
%R 10.1007/PL00001152
%T Earthquake location accuracies in Norway based on a comparison between
local and regional networks
%U http://dx.doi.org/10.1007/PL00001152
%V 158
%X Detailed studies of the low to intermediate seismicity in two coastal
regions of Norway have been used in a comparison between earthquake
locations from local high-precision networks on the one side and
locations using a sparse regional array network on the other side.
To this end, a reference set of 32 low-magnitude earthquakes have
been located using two local temporary networks in northern and western
Norway, with estimated epicenter accuracies better than 5 and 10
km, respectively. Comparisons are made between the local network
solutions and the NORSAR Generalized Beamforming (GBF) system, which
provides automatic phase association and location estimates using
the Fennoscandian regional array network. The median automatic GBF
location error is of the order of 20-30 km when four or more arrays
detect the event, increasing to about 80-100 km when only two arrays
are available, and the automatic GBF bulletin is essentially complete
down to magnitude ML = 2.0. Most of the mislocation vectors of the
NORSAR GBF solutions are oriented perpendicular to the Norwegian
coast, and with a tendency to pull the location in a southeasternly
direction. The GBF performance is clearly better, both in terms of
accuracy and completeness, than the performance of the automatic
bulletin of the Prototype International Data Center (PIDC) which
uses data from essentially the same network. The analyst reviewed
NORSAR and PIDC bulletins show, not unexpectedly, an improvement
in location accuracy compared to the automatic solutions and appear
to be of similar quality for the few common events, with an average
mislocation of about 20ukm. The NORSAR reviewed bulletin is more
complete at low magnitudes compared to PIDC, and there appears to
be a potential for significant improvements in the PIDC processing
of small seismic events in this region.
@article{hicks_etal:2001,
abstract = {Detailed studies of the low to intermediate seismicity in two coastal
regions of Norway have been used in a comparison between earthquake
locations from local high-precision networks on the one side and
locations using a sparse regional array network on the other side.
To this end, a reference set of 32 low-magnitude earthquakes have
been located using two local temporary networks in northern and western
Norway, with estimated epicenter accuracies better than 5 and 10
km, respectively. Comparisons are made between the local network
solutions and the NORSAR Generalized Beamforming (GBF) system, which
provides automatic phase association and location estimates using
the Fennoscandian regional array network. The median automatic GBF
location error is of the order of 20-30 km when four or more arrays
detect the event, increasing to about 80-100 km when only two arrays
are available, and the automatic GBF bulletin is essentially complete
down to magnitude ML = 2.0. Most of the mislocation vectors of the
NORSAR GBF solutions are oriented perpendicular to the Norwegian
coast, and with a tendency to pull the location in a southeasternly
direction. The GBF performance is clearly better, both in terms of
accuracy and completeness, than the performance of the automatic
bulletin of the Prototype International Data Center (PIDC) which
uses data from essentially the same network. The analyst reviewed
NORSAR and PIDC bulletins show, not unexpectedly, an improvement
in location accuracy compared to the automatic solutions and appear
to be of similar quality for the few common events, with an average
mislocation of about 20ukm. The NORSAR reviewed bulletin is more
complete at low magnitudes compared to PIDC, and there appears to
be a potential for significant improvements in the PIDC processing
of small seismic events in this region.},
added-at = {2012-09-01T13:08:21.000+0200},
author = {Hicks, E. C. and Bungum, H. and Ringdal, F.},
biburl = {https://www.bibsonomy.org/bibtex/2d1e0551d75e49429b9aa97122560b697/nilsma},
day = 1,
doi = {10.1007/PL00001152},
interhash = {ded772fc973f756c44a1642ae1bfe0d2},
intrahash = {d1e0551d75e49429b9aa97122560b697},
issn = {0033-4533},
journal = {Pure and Applied Geophysics},
keywords = {geophysics seismology},
month = feb,
number = {1-2},
pages = {129--141},
publisher = {Birkh\"{a}user Basel},
timestamp = {2021-02-09T13:21:14.000+0100},
title = {Earthquake location accuracies in Norway based on a comparison between
local and regional networks},
url = {http://dx.doi.org/10.1007/PL00001152},
volume = 158,
year = 2001
}