Publication Date:
2017-04-04
Description:
An effective early-warning system must provide probabilistic estimates
of the location and size of a potentially destructive earthquake within a few seconds
after the event is first detected.
In this work we present an evolutionary, real-time location technique based on an
equal differential time (EDT) formulation and a probabilistic approach for describing
the hypocenter estimation. The algorithm, at each timestep, relies on the information
from triggered arrivals and not-yet-triggered stations. With just one recorded arrival,
the hypocentral location is constrained by the Voronoi cell around the first triggering
station constructed using the travel times to the not-yet-triggered stations.With two or
more triggered arrivals, the location is constrained by the intersection of the volume
defined by the Voronoi cells for the remaining, not-yet-triggered stations and the EDT
surfaces between all pairs of triggered arrivals. As time passes and more triggers become
available, the evolutionary location converges to a standard EDT location.
Synthetic tests performed using the geometry of the Irpinia seismic network,
southern Italy (ISNet), and the simulation of an evolutionary location for the 2000
Mw 6:6 Western Tottori, Japan, earthquake indicate that when a dense seismic network
is available, reliable location estimates suitable for early-warning applications
can be achieved after 1–3 sec from the first event detection. A further simulation with
an Mw 6:7 southern Greece earthquake shows that at a regional scale, the real-time
location can provide useful constraints on the earthquake position several seconds
before a non-real-time algorithm. Finally, we show that the robustness of the algorithm
in the presence of outliers can be effectively used to associate phase arrivals coming
from events occurring close in time, and we present a preliminary algorithm for event
detection.
Description:
Published
Description:
1482–1494
Description:
4.1. Metodologie sismologiche per l'ingegneria sismica
Description:
JCR Journal
Description:
reserved
Keywords:
Early warning
;
earthquake location
;
04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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