Title: Broadband data processing of earthquakes recorded with the seismological network in Denmark and Greenland
1Broadband data processing of earthquakes recorded
with the seismological network in Denmark and
Greenland
P. Voss T.B. Larsen Geological Survey of
Denmark and Greenland - GEUS
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2Seismograph network
Denmark
Greenland
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3Core Areas
The instruments compose a triangle with sides of
approx. 3000km length
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4Core Events
Epicenters JUN 1998 to JUN 2008
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5The weekly bulletin
- Single station phase reading. - Phase
readings are unassociated. - Location of distant
earthquakes not our problem - Location of local
earthquakes Extra work - Include observations
from neighbor networks Extra work
Example of the weekly bulletin
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6The New Bulletin
- Event based bulletin. - Phase picking and
location is preformed in the same working
process. - Phase readings are associated with
few exceptions. - Location of distant
earthquakes Preformed, but location errors
can be very large. - Location of local
earthquakes Done within a few days. - Include
observations from other networks Extra work.
Example of the new bulletin
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7Earthquake Bulletin
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8Power Spectral Density Probability Density
Function
Power 10log10(m2/sec4/Hz)db
Ref. McNamara, D.E., R.I. Boaz, Seismic Noise
Analysis System, Power Spectral Density
Probability Density Function Stand-Alone
Software Package, USGS Open-File Report, 2005.
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9Status of the DNK network
Improvements - Defined core areas. - Event
based database. - Old analog phase readings have
been added to the database. - Macroseismic
information is added to the database.Work in
progress - Improve the tools for including
information from neighbor networks. - Improve
the location and phase association of distant
earthquakes. - Upgrade more stations to real
time stations. - Registration of known
explosions. - PDF quality control Future
- Calibration of the ML magnitude formula. -
The generational succession.
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10Data example Distant Earthquake
M6.6 2008/05/31 0437 MID-INDIAN RIDGE
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11Data example Regional Earthquake
ICELAND
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12Data example Local Earthquake
Baffin Bay
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13Thank you
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