on going development of a seismic alert management system for the campania region (southern italy)...
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On going development of a seismic alert management
system for the Campania region (southern Italy)
A. Zollo(1), G. Iannaccone(2),C.Satriano(1), E.Weber(2), M. Lancieri (1) and A. Lomax(3)
(1) Research Unit RISSC, Dip. di Scienze Fisiche, Università di Napoli Federico II(2) Research Unit RISSC, Osservatorio Vesuviano, INGV, Napoli(3) Anthony Lomax Scientific Software Mouans-Sartoux, France
• WHY
an earthquake early warning system in southern Italy
• WHAT
are the system architecture and components
• HOW
does it work WH
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Outline
A pilot project to experiment a system for earthquake early warning and rapid evaluation of ground motion scenarios in the Regione Campania
Objectives:• Early-Warning and Rapid Ground shaking scenarios• Remote control and protection of a selected target
Time Schedule: end 2005 real-time seismic network completionend 2006 upgrade data transmission system
Financial support: Campania Region - Department of Civil Protection
AMRA Regional Center for Analysis and Monitoring of Environmental RisksWH
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SAMS: A Seismic Alert Management System for the Campania Region
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HYRegional historical seismicity
Tyrrenian sea
Cam
pania
Region
Peak accelerations & velocities modified from Cabanas et al., 1998
Intensity map, modified from De Rubeis et al., 1996
Ground shaking during the 1980, Irpinia Earthquake, Ms=6.9
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HYRecent earthquake activity
INGV catalogue (1981-2002), M>2.5
Rate of occurrence
Probability map of moderate to large earthquakes (Min Italy for the next 10 years (Cinti et al., G3, 2005)
southernApennines
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Instrumental data (Boschi et al,2003)
M>4.0 1 event every 1.5 years
M>5.0 1 event every 4 years
M>6.0 1 event every 32 years
Potential targets for an EWS in Campania region
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city of Napoli
hospitals
fire stations
gas/electric pipelines
industries
railways
highways
4 small towns
• Moderate events (M4.5) are of interest social impact, loss of occupancy
• Short hypocentral distances narrow “early warning” windows
• Multiple rupture events complexity/ reliability of location/magnitude estimations
Peculiarities / criticalitiesW
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EEW seismic network & seismicityW
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“Shake map”network “Early warning”
network
Three levels of data acquisition and transmission:
> Stations (data loggers)> Local Control Center (sub-nets)> Network Control Center (Naples)
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HYNetwork architecture
LocalControlCenters
Sub-nets
Stations
Data transmission system:data logger LCC: point-to-point Wireless LAN bridgeLCC LCC : backbone (SDH) / ADSLLCC Network center (Naples): backbone (SDH) / ADSL
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HYCommunications
7-23 GHz
55-150 Mbps
2.4 GHz54 Mbps
• Local Control Center: Fully automated. Manages and processes the sub-net data (seedlink protocol & Earthworm data management system)
• Data logger: on-site computational capabilities (event detection, automatic P time, peak amplitude, P-frequency,..)
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Local Control Center
Seismic station
The seismic instrumentsW
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Embedded Linux and Open Source Software
24-bit AD converter
Removable mass storage (2 PCMCIA slots 5Gb)
ARM720T processor, supervisory system
6 channels: 3 accelerometers + 3 seismometers (Short Period or Broad Band)
1. Event detection (STA1)2. LCC1 linked to the closest
station, verifies the event coincidence, collects and processes P-waveform data (time, amplitude, ..)
3. LCC1 estimates the hypocenter location and magnitude with errors (X, DX, M, DM)
4. New data entries from progressively distant stations LCC1 updates estimates of X,DX,M,DM
5. Alert notifications to end-users is sent after each up-dating step
LCC1
STA1
EQK
Operational modeW
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To timeT_first_P T_S_target
1.5 – 3.5 sec for eqk at depths of 4-16 km
60 km 80 km 100 km
16 – 18 s 22 – 24 s 28 – 30 s
Latency/computational
3-5 sec
Characteristic times for EEWW
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Bagnoli (22 km)Calitri(20 km)
1980 Irpiniaearthquake
Ms=6.9
TPmax (4sec)
M
Tpm
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Allen & Kanamori,2003
Source parameter estimates
Moment/Magnitude:
P and early-S max amplitudes
v^2 plots instantaneous period
Location:
Trigger station order (Voronoi cells)
Equal differential time (Lomax,2004)
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To + 3 secTo + 4 secTo + 5 secTo + 6 sec
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HYP-wave detection capability vs time
At each time step, the map shows the number of stations which would record the first-P wave of an earthquake occurring at 12 km depth beneath the network
wavefront
hypocenter
stations(operational)
Voronoi cellboundaries
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HYEvolutionary earthquake location 1/4
“conditional”EDT surface
volume definedby stations
without arrivals
First station detects arrival – constraint is Voronoi cells
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ttB ttA 0
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HYEvolutionary earthquake location 2/4
“conditional”EDT surface
Wavefront expands – EDT surfaces deform, constraint improves
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ttB ttA tnow tA
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“true”EDT surface
Second station detects arrival – constraint includes EDT surface
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ttB ttA tB tA
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HYEvolutionary earthquake location 4/4
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HYVoronoi cells of Irpinia network
Voronoi cells give the location of the eqk epicenter (no depth!) constrained by a single station trigger
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HYReal time eqk location: Simulation
The plotted quantity is proportional to the probability of earthquake location at a given point
Map at 12 km depth
Tnow=0.0 is the time of first-P at the closest station
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Second station detects P-arrival
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P-wave arrives at nine stations within 2 sec from the first-P at the closest station
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Conclusions
A high-density, high dynamics (strong motion + seismometers) seismic network is under installation in Campania region for “regional” early-warning applications
The main targets are strategic infrastructures located at distances such that expected S-wave lead time is around 20-30 sec
The network architecture is designed to have distributed levels of data storage, communication and decisions
On going development of methods for earthquake location, magnitude estimation. Need to provide parameter uncertainty variation with time engineering structural control
An example: the evolutionary earthquake location approach
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