IRIS workshop on
“Managing Waveform Data and Related Metadata from Seismic
Networks” Hotel Windsor Suites, Bangkok, Thailand
08-13, January, 2012
Ashvin WickramasooriyaSenior Lecturer in Earth Science
South Eastern University of Sri Lanka
CONTENTS
OVERVIEW
SRI LANKAN SEISMIC NETWORK
SOUTH EAST SEISMIC STATION
SPECIFICATIONS:
SENSORS/LOGGER/SOFTWARE
OverviewThere was no seismic network system for Sri Lanka before 2005
However, a single seismic station was established in 1996 under the Global Seismic Network (GSN) at Pallekale, Kandy
First Sri Lankan Seismic Network has established in June, 2005 funded by the Japanese Government (JICA)
1) Detect a domestic earthquake and calculate
Epicenter and Magnitude
2) Post processing function
3) Data communication: Telephone Line (Dial up)
(To reduce the running cost)
4) Four Seismic Stations (To calculate Epicenter)
Initial Plan of establishing this seismic network include :
SRI LANKAN SEISMIC NETWORK
June , 2005 Funded by JICA
There are four seismic stations were established under this network at four universities.
Local station(RHN)Ruhuna Univ.
Local station(RJR)Rajarata Univ.
Central Station (PRD)Peradeniya Univ.
Local station(EST)South-East Univ.
Overview (Function)1) Continuous Data recording (6ch, one
month) 6ch: Acceleration 3ch, Velocity 3ch
2) Automatic Trigger Function and Call to Central Station (Peradeniya)
3) Automatic Data correction from Central
Station to Local Station (Manual correction is also Available)
4) Automatic Processing Function (SEISAN) Epicenter(Domestic) , Magnitude
5) Post Processing Function (SEISAN)
Software for Central StationData Collection from each stations
Data StorageData Analysis *Epicenter *Magnitude *Spectrum etc
Maintenance (Each station )
Telephone Line
Data Logger
(6ch)
with GPS
Personal
Computer
Hub
Printer
U P S
Modem
TCP/IP Protocol Converte
r
Router
Concrete BaseOutside
Inside
Central Station (Peradeniya)
UNIV.LAN
Short period
seismometer
Forcebaranse servo
accelerometer
RAJRHN
SET
Telephone Line
Data Logger
(6ch)
with GPS
Personal
Computer
Hub
Printer
U P S
Modem
TCP/IP Protocol Converte
r
Router
Concrete BaseOutside
Inside
Local Stations(Rajarata, Ruhuna, South-Eastern)
Short period
seismometer
Forcebalance servo
accelerometer
Software for Local stationData Collection (Own site, Manual)Data Storage (Do)Maintenance (Own site)
Central Station
SOUTH EAST SEISMIC STATION
1. Sensor: 1)Forcebalance Servo
Accelerometer :Episensor 2)Seismometer (1Hz Geophone):GS-1 2. Data Logger: 24bit Data Logger : Altus K2
3. Data Acquisition: PC Based System : Recording: SMARTS Processing: SEISAN
4. Communication: Telephone line (Analog, Dial-up)
Sensors
SeismometerGS-1
AccelerometerEpisensor
• Epi-sensor Suitable for Strong motion • GS-1 Suitable for Micro-seismic
Data logger
Site Installation
Installation
Data Processing system
Resolution & Dynamic Range
• Full scale of K2 : 2.5V
• A/D resolution : 2.5V/223 = 0.298 microV
• Acceleration: (0.23mgal) – 1960 gal
– Effective resolution: 10 mgal ?
• Velocity: (0.0745 microkine) – 625 mkine
– Effective resolution: 10 microkine?
• GS-1 for small earthquake
• Epi-sensor for strong motion
Software configuration
SMARTS
Continuous Waveform (evt file)
Trigger Information (text file)
SMARTS-Sri-Lanka (Program package)
evt2sei.pl
SEISAN
Waveform (SEISAN format)
event file (SEISAN format)
Local Stations
Central Station
Thank You