A new System for Earthquake Detection and Source Parameters Determination in Italy S. Mazza, F. Mele, M. Olivieri, S. Pintore, M. Quintiliani, L. Scognamiglio,

1
A new System for Earthquake Detection and Source
Parameters Determination in Italy S. Mazza, F.
Mele, M. Olivieri, S. Pintore, M. Quintiliani, L.
Scognamiglio, G. Selvaggi

• Istituto Nazionale di Geofisica e Vulcanologia,
  Roma, Italy

2
The Italian Seismic Network

• About 200 ingv digital station with different
  seismometers, digitizers and trasmission media
• 30 from other Italian organizations
• 30 from foreign countries
• 60 accelerometers
• SP analog
• BB (Gaia-INGV Nanometrics)
• VBB (MedNet)

3
The Italian Seismicity

• Last 3 years only (from the Italian Bulletin)
• Irregular Country shape
• Inhomogeneous station distribution

4
Goal

• Upgrade to compare with a modern network
• Overcome the limitations of the old concept
• Realize a robust and versatile system

It is just a part, although the most sensible of
a complex system for data acquisition,
processing, archiving and distribution
5
EarthWorm

• Very many requirements
• Reliable
• Unmanned
• Self controlled
• Major failures notifications
• Rapid
• rapid automatic information to face INGV
  commitment with the Italian Civil Protection
• about all eqs in Italy with Ml gt 2.5 with 2-5-30
  minutes rule
• about all eqs in the EuroMediterranean region
  with Ml gt 5.0

6
EarthWorm

• Efficient
• to minimize the false alarms
• to match the detection capacity of the old system
• Versatile
• Fulfilling multiple requirements
• Integrate local network at different levels
• Open
• Development
• Formats
• Well documented

7
Schema
8
OS and HW

• Solaris10 Sun Sparc box.
• Reliability and Robustness
• Completeness of Earthworm packages
• Open source development tools available
• Two identical processing machines
• A third machine for development and tests

9
Open development

• EW modules developped or modified to fit our
  needs.
• nmxptool
• arcto3g
• ingv_report
• Interactive tools

10
Difficulties

• Tuning some modules
• Picker pick_ew
• Binder binder_ew
• Many configuration files
• procedures to automatically create configuration
  files using our pre-existent Database.

11
Results

• Three main differences between the two systems
  being compared
• EW is unmanned
• We have imposed that EW has at least 4 stations
  to start a location
• EW does not include 40 analog sp stations

12
Results missed events
Number of events
Ml
13
Results Epicentral comparison
Each circle center is the manually revised
epicenter, while radius is the distance to EW
result
Number of events for each beam of epicentral
distance
14
Results EW-only events
Triangles are earthquakes detected only by
Earthworm, In red false events, true ones in
green. Green triangles in the Ionian Sea are not
representative
15
Conclusions

• Work is in progress, but first results are very
  satisfactory.
• A good group is slowly growing to nurse the
  system.
• Some major improvements are already in the air.
• We already have a backup system for the
  present, limping one.

16
Thanks

• Thanks to Alfonso Mandiello,
• Valentino Lauciani,
• Remo Moro,
• Carlo Marcocci,
• Paul Frieberg and ISTI people,
• Alberto Michelini.

17
(No Transcript)