Seismic network and earthquake
rapid report in Taiwan
Peih-Lin Leu andNai-Chi Hsiao*
Central Weather Bureau (CWB), Taiwan

June 4, 2012

Seismic networks in operation
CWBSN

TSMIP

TGNS

Central Weather Bureau
Seismic Network

Taiwan Strong Motion
Instrumentation Program network

Taiwan Geophysical Network
for Seismology

Tasks:
 Earthquake catalog
 Earthquake rapid notification andearly warning Tsunami warning Seismological related research

Tasks:
 Strong-motion database Strong-motion seismology
research
 Earthquake engineering
application

Tasks:
 Geophysical database Earthquake precursor study Crustal deformation and active
fault monitoringCWBSN framework

137stations totally

6-channel station
Integrate and upgrade all of
Taiwan’s short-period
stations in 1991. Add strongmotion seismometers instations in 1995.
The main seismic stations
for earthquake observationin Taiwan for the past 20years.
Totally upgrade theresolution to 24 bits in 2012.
69 stations established.

4

Broadband station
Start to build the stations
and install broadband
seismometers in 2001.
High quality and resolution
data are acquired forseismological relatedresearch.
33 stations established.

5

Downhole station
Start to build the stations in2007 in order to establish
the next generation ofseismic station in Taiwan.
Borehole depth is set to 300
meter.
3 seismometers are installed
in a station, include 1
borehole broadband sensor,
1 borehole FBA sensor, and1 surface FBA sensor.
20 stations established, andplan to build 70 stations
totally for the next few years.
6

Downhole station framework
DAU
FBA

Frame Relay

SMART-24R

diameter 5inch

PA-23

300m

PA-23BH
KS-2000BH

FBABB18m

Specification
1. Well type：dry
2. Well material：anti-rust steel
3. Drilling depth：318m
4. Well length：300m

grouting
7

OBS station
1 cable based OBS station isconstructed off northeastern
Taiwan in 2011 to improve thecapabilities of earthquake
monitoring.
Cable laid from Toucheng,
Yilan county. The cable lengthis about 45 km, and the water
depth of station is about 300
meter.
1 broadband sensor and 1
FBA sensor are installed.
Plan to extend the cable
length and add more OBS inthe future.
8

OBS system framework

Integrated data processing platform
FBA+SPBBOBS

Others

Downhole

Frame Relay、ADSL、GPRS、Marine CableRetrieving
moduleRetrieving
moduleRetrieving
moduleRetrieving
moduleRetrieving
moduleLAN
USGS Earthworm Cluster
1.Collecting & integrating different type data
2.Producing various seismic files forfurther processing

Data Exchange

LAN
ERR/EEW

Seismicity
observation

CMT

Other
research

DatabaseReal-time data integration
Earthworm
Real-time
data

Tankplayer

WAVE_RING

Waveserver

Pick_eew

Waveman2disk

Tank

Strong-motion,
Broadband,
Short period

Processing
programSpecific format
dataSAC,MiniSeed,
SUDS,
TANK,
CWB24

Processing
program(陳達毅)

Main tasks in operation
 Earthquake catalog publish
 Earthquake rapid reporting Earthquake early warning

Earthquake catalog publish

Magnitude of completenessFrequency-Magnitude distribution(張建興)

Earthquake catalog publish

Taiwan earthquake catalog(張建興)

Earthquake catalog publish

Seismicity observation(張建興)

Earthquake catalog publish

Seismogenic structure study(張建興)

Earthquake rapid reporting

Earthquake rapid notification

Earthquake rapid reporting

Earthquake report statistics
2006~2011
781 Events

5.36 6.72 km

4.97 5.96 km

Earthquake rapid reporting

Reporting time
2006~2011自動定位與地震報告發布時效

22:30

發布報告平均時效 04:48 ± 02:31

20:00

自動定位平均時效 48 ± 12 sec

4:48 2:31
48 12 sec

Reporting time

17:30

時
效

15:00

12:30

10:00

07:30

5 min
05:00

02:30

00:00
2006/01

2006/07

2007/01 2007/07

2008/01

2008/07

2009/01

2009/072010/01

2010/07

Occurrence of earthquake

2011/01

2011/07

Earthquake rapid reporting

Example (Wutai earthquake)
Eq.

February 26, 2012
M6.4 Wutai earthquake>Automatic earthquake report 50 sec

Seismic Intensity map / Location of the earthquake>Mobile phone text message>E-mail 59 sec
 59 sec>Confirmed earthquake report>Mobile phone text message>Web server>Phone inquiries>FAX 03:59
 04:00
 04:00
 04:00
 04:00>TV channels

 05:08

Earthquake early warning

Virtual Sub-Network for EEWEarthquake early warning

EEW Capability
2006~2011
161/172 Events (93.6%)

0.28 0.24

18.7 3.2 sec

6.57 8.75 km

5.10 5.05 km

Earthquake early warning

Advanced EEW procedure developed
1.Pick P wave arrival
2.Calculate P wave
amplitudes and period

Real-time data
packet input

Earthworm
WAVE_RING

Pick_eew

Earthworm
PICK_RING

Earthquake Early Warning Report

tcpd
1.Locate earthquake
2.Estimate magnitudeMτc = 4.218 * log10(τc )+6.166(Wu et al., 2010)

MPd = 3.905 + 2.198 * log10(Pd) + 2.703 * log10(R) (Hsiao et al., 2010)(陳達毅)

Earthquake early warning

Example(陳達毅)

The End
Thank you for your attention!

Earthquake early warning

Intensity estimate
161個地震中3539筆震度預估，與實際觀測值比較，震度完全吻合者53%，震度相差1級者44%，相差2級者3%。
ⅠpⅠo1

2

3

45672

297

1164

534

20000324321

512

135

8004036168

163

240050026

5837206000

4

5

00

7

0000

1

00