HR: 0800h
AN: S51D-1032
TI: Real-Time Estimation of Earthquake
Location, Magnitude and Rapid Shake map Computation for the Campania
Region, Southern Italy
AU: * Zollo, A
EM: aldo.zollo@na.infn.it
AF: Dip. Scienze Fisiche,Universita' di
Napoli Federico II, Compl Univ. M.S.Angelo v. Cinthia, Napoli,
80125 Italy
AU: Convertito, V
EM: converti@na.infn.it
AF: Dip. Scienze Fisiche,Universita' di
Napoli Federico II, Compl Univ. M.S.Angelo v. Cinthia, Napoli,
80125 Italy
AU: De Matteis, R
EM: raffa@na.infn.it
AF: Dip.di Studi Geol e Amb,Universita'
del Sannio, via Bortarsa,11, Benevento, 82100 Italy
AU: Iannaccone, G
EM: iannaccone@ov.ingv.it
AF: Istituto Nazionale di geofisica e
Vulcanologia, v. Diocleziano, 328, Napoli, 80124 Italy
AU: Lancieri, M
EM: lancieri@na.infn.it
AF: Dip. Scienze Fisiche,Universita' di
Napoli Federico II, Compl Univ. M.S.Angelo v. Cinthia, Napoli,
80125 Italy
AU: Lomax, A
EM: anthony@alomax.net
AF: Anthony Lomax, Scientific Software,
161 Allee du Micocoulier, Mouans-Sartoux, 06370 France
AU: Satriano, C
EM: satriano@na.infn.it
AF: Dip. Scienze Fisiche,Universita' di
Napoli Federico II, Compl Univ. M.S.Angelo v. Cinthia, Napoli,
80125 Italy
AB:
A prototype system for earthquake early warning and rapid shake map
evaluation is being developed and tested in southern
Italy based on a dense, wide dynamic-range seismic network
(accelerometers + seismometers) under installation in the
Apenninic belt region (Irpinia Seismic Network). This system forms a
regional
Earthquake Early Warning System consisting of a seismic sensor network
covering a portion of the expected epicentral area for large
earrthquakes.
Considering a warning window ranging from tens of seconds before to
hundred of seconds after an earthquake, several public
infrastructures and buildings of strategic relevance (hospitals, gas
pipelines, railways, railroads, ...) of the Regione
Campania are potential test-sites for testing innovative technologies
for data acquisition, processing and transmission.
A potential application of an early warning system in the Campania
region based on the Irpinia network, should consider an
expected time delay to the first energetic S wave train varying between
14-20 sec at 40-60 km distance to 26-30 sec at about
80-100 km, from a crustal earthquake occurring in the source region.
The latter is the typical time window available for
mitigating earthquake effects through early warning in the city of
Naples (about 2 million of inhabitants including suburbs).
We have developed a method for real time earthquake location following
a probabilistic approach. The earthquake location is
expressed as a probability density function for the hypocenter location
in 3D space based on the concept of equal
differential-time (EDT). It provides a location as the maximum of a
stack over quasi-hyperbolic surfaces. On each surface the difference of
calculated travel-times at a pair of stations is equal to the
difference of observed arrival times at the same pair of stations. For
an increasing number of P-wave readings, progressively acquired in the
short time after the occurrence of an earthquake, the EDT method can be
generalized by introducing an evolutionary strategy which is aimed at
obtaining a
more and more refined estimate of the maximum probability volume as the
time goes on.
The real time magnitude estimate will take advantage from the high
spatial density of the network in the source region and
the wide dynamic range of installed instruments. Based on the offline
analysis of high quality strong-motion data bases
recorded in Italy and worldwide, several methods will be checked and
validated , using different observed quantities (peak
amplitude, dominant frequency, square velocity integral, .) to be
measured on seismograms, as a function of time.
Following the ElarmS methodology (Allen,2004), peak ground attenuation
relations can be used to predict the distribution of
maximum ground shaking, as updated estimates of earthquake location and
magnitude are progressively available from the Early
Warning system starting from the time of first P-wave detection. As
measurements of peak ground quantities for the current
earthquake become available from the network, these values are
progressively used to adjust an "ad hoc" determined
attenuation relation for the Campania region using the stochastic
approach proposed by Boore (1993).
DE: 7212 Earthquake ground motions and
engineering seismology
DE: 7215 Earthquake source observations
(1240)
SC: Seismology [S]
MN: Fall Meeting 2005
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