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