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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HYFonctionality

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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HYEvolutionary earthquake location 3/4

“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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HYReal time eqk location: Simulation

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HYReal time eqk location: Simulation

Second station detects P-arrival

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HYReal time eqk location: Simulation

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HYReal time eqk location: Simulation

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HYReal time eqk location: Simulation

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HYReal time eqk location: Simulation

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HYReal time eqk location: Simulation

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HYReal time eqk location: Simulation

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HYReal time eqk location: Simulation

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HYReal time eqk location: Simulation

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HYReal time eqk location: Simulation

P-wave arrives at nine stations within 2 sec from the first-P at the closest station

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HYReal time eqk location: Simulation

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HYReal time eqk location: Simulation

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