Earth-prints repository, logo   DSpace

About DSpace Software
|earth-prints home page | roma library | bologna library | catania library | milano library | napoli library | palermo library
Please use this identifier to cite or link to this item: http://hdl.handle.net/2122/2523

Authors: Massa, M.*
Ferretti, G.*
Spallarossa, D.*
Eva, C.*
Title: Improving automatic location procedure by waveform similarity analysis: An application in the South Western Alps (Italy)
Title of journal: Phys. Earth Planet. Inter.
Series/Report no.: / 154 (2006)
Publisher: Elsevier
Issue Date: 2006
DOI: 10.1016/j.pepi.2005.07.003
URL: http://www.elsevier.com/locate/pepi
Keywords: Automatic location procedure
Waveform similarity analysis
Cross-correlation methodology
South Western Alps seismicity
Abstract: The accuracy of automatic procedures for locating earthquakes is influenced by several factors such as errors in picking seismic phases, network geometry, modeling errors and velocity model uncertainties. The main purpose of this work is to improve the performances of the automatic procedure employed for the “quasi-real-time” location of seismic events in North Western Italy by developing a procedure based on a waveform similarity analysis and by using only one seismic station. To detect “earthquake families” a cross-correlation technique was applied to a data set of seismic waveforms recorded in the period 1985–2002, in a small test area (1600 km2) located in the SouthWestern Alps (Italy). Normalized cross-correlation matrices were calculated using about 2700 seismic events, selected on the basis of the signal to noise ratio, manually picked and located by using the Hypoellipse code. The waveform similarity analysis, based on the bridging technique, allowed grouping about 65% of the selected events into 80 earthquake families (multiplets) located inside the area considered. For each earthquake family a master event is selected, manually re-picked and re-located by using Hypoellipse code. Having chosen a reference station (STV) on the basis of the completeness of the available data set, an automatic procedure has been developed with the aim of cross-correlating new seismic recordings (automatically picked) to the waveforms of the events belonging to the detected families. If the new event is proved to belong to a family (on the basis of the cross-correlation values), its hypocenter co-ordinates are defined by the location of the master event of the associated family. The performance of the proposed procedure is tested and demonstrated using a data set of 104 selected earthquakes recorded in the period January 2003–June 2004 and located in the test area. The automatic procedure is able to locate, associating events with the multiplets detected by the waveform similarity analysis, about 50% of the test events, almost independently of the accuracy of the automatic phase picker and without the biasing of the network geometry and of the velocity model uncertainties.
Appears in Collections:04.06.09. Waves and wave analysis
Papers Published / Papers in press

Files in This Item:

File SizeFormatVisibility
292.pdf959.53 kBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.


Share this record
Del.icio.us

Citeulike

Connotea

Facebook

Stumble it!

reddit


 

Valid XHTML 1.0! ICT Support, development & maintenance are provided by CINECA. Powered on DSpace Software. CINECA