Publication Date:
2017-04-04
Description:
Abstract We present an update of the local magnitude scale previously calibrated
for northwestern Turkey by Baumbach et al. (2003). The path coverage in the westernmost
part of the analyzed area has been increased, as well as the number of
amplitudes for distance greater than 110 km. Furthermore, a set of recordings from
accelerometric stations operated by the Kandilli Observatory and Earthquake Research
Institute (KOERI) has been merged with the recordings by the Sapanca-Bolu
and German Task Force seismological networks. In all, 4047 recordings from
528 earthquakes recorded by 31 seismometers and 23 accelerometers are considered
to calibrate the local magnitude scale over a hypocentral distance range from 10
to 190 km. By analyzing the unit covariance matrix and the resolution matrix, we
show how the source-to-station geometries of the seismic and strong-motion networks
affect the uncertainties of the computed station corrections, attenuation coefficients,
and magnitudes. The assumptions made concerning the reference station
correction, and the change in the amplification for the Wood–Anderson torsion seismograph
from 2800 to 2080 (Uhrhammer and Collins, 1990) introduced an offset of
about 0.34 in the magnitudes with respect to Baumbach et al. (2003), with the updated
local magnitude scale ranges from 0.50 to 5.91. The distribution of the residuals with
distance confirms that the extension of both the magnitude and distance ranges and
the improved path coverage have preserved the high quality that characterized the
data set analyzed by Baumbach et al. (2003).
Description:
Published
Description:
331-338
Description:
3.3. Geodinamica e struttura dell'interno della Terra
Description:
JCR Journal
Description:
partially_open
Keywords:
local magnitude
;
04. Solid Earth::04.06. Seismology::04.06.09. Waves and wave analysis
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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