Seismic Networks Operated

by Central Weather Bureau in Taiwan

Ta-Yi Chen

Central Weather Bureau

Outline

•Seismicity in Taiwan

•CWB Seismic Networks

•Integrated Seismic Network

•System Architecture

•Data Format

Seismicity in Taiwan

Magnitude Range Average (Numbers/Year)

7 M≦ L 0.1

6 M≦ L ＜ 7 2.6

5 M≦ L ＜ 6 22

4 M≦ L ＜ 5 197

0 M≦ L 19,175

Current Seismic Networks （ since 1991）

• Strong-Motion Seismic Network (110)

Dynamic Range : 16bitSampling Rate : 50spsType of Seismometer: Smart24aType of telemetry : Telephone LineTime mark is given in Central Station.

• Short-Period Seismic Network (71)

Dynamic Range : 12bitSampling Rate : 100spsType of Seismometer: S13Type of telemetry : Telephone LineTime mark is given in Central Station.

S13 in Bore-Hole

S13 on Surface Smart24a on Surface

Updated Seismic Network

68 station done

• Integrate short-period and strong-motion data streams into 1 recorder (Smart24a).

• Dynamic Range : 24bit

• Sampling Rate : 100sps

• Type of Telemetry : Frame Relay, ADSL

Time mark is given on site by GPS.

Broad-Band Seismic Network

• Broad-Band Seismic Network (33)Dynamic Range : 24bitSampling Rate : 100spsType of Seismometer: CMG-3ESP, CMG-40TDType of Digitizer: DM24Type of telemetry : Frame RelayTime mark is given on site by GPS.

CMG-3ESPDM24

Bore-Hole Seismic Network

Done

Phase II

Phase III

• Dynamic Range : 24bit

• Sampling Rate : 100sps

• Type of Telemetry : Frame Relay

• Type of Digitizer: Smart24r

Time mark is given on site by GPS.

• Each site is equipped with 3 different instruments

• ~300 m in depth

17 stations Have Been Done

70 stations in Final Step

Cable Ocean Bottom Seismic Network

Latit

ude

Longitude

Sea Depth Meter

Land Station

Observed Node

• Black line: achievedachieved in 2011• Blue line: ongoingongoing project as the phase II• White line: plannedplanned project as phase III

• Dynamic Range : 24bit

• Sampling Rate : 100sps

• Type of Telemetry : Frame Relay

Time mark is given on site.

Central Weather Bureau, Taiwan

Updated Seismic NetworksBore-Hole Seismic Network

Cable Ocean Bottom Seismic Network

Institute of Earth Sciences, Academia Sinica , Taiwan

Broadband Array in Taiwan for Seismology (BATS)

Yangmingshan (YMS) Volcano Seismic Network

Other Institutions

Incorporated Research Institutions for Seismology (IRIS)

: 3 JMA (Japan) Stations

Integration for all CWB Seismic Networks

Station Channel Network Location

Network (Network Type)

CWB_BH CWB Bore Hole

CWB_BB CWB Broad Band

CWB_SMT CWB Smart24

IRIS_JPN IRIS Japan

IES_YMS IES YMS

IES_BATS IES BATS

Channel (Instrument Type)

Ch1~Ch3 Strong Motion (Z ， N ， E)

Ch4~Ch6 Short Period (Z ， N ， E)

Ch7~Ch9 Broad Band (Z ， N ， E)

Location (Position of Instrument)

01 Surface

02 Bore Hole

03 Ocean Bottom

Policy of SCNL

測站 Station Channel Network Location

Acceleration of Smart24 CHK Ch1~Ch3 CWB_SMT 01

Short Period of Smart24 CHK Ch4~Ch6 CWB_SMT 01

Broad Band in Surface CHK Ch7~Ch9 CWB_BB 01

Broad Band in Bore Hole CHK Ch7~Ch9 CWB_BB 02

Example: Cheng Kung Station

Integrated Seismic Network

68

17

33

21

9

3

The Earthworm system is used forintegrating seismic networks.

Operators are able to request differentkinds of real-time data from thisEarthworm system.

115 120 125 13020

22

24

26

28

Total 144 Sites 249 Instruments

module module module module module

ReceivingLayer

IntegratedLayer

ApplicationLayer

Earthworm Earthworm EarthwormData Exchange

TCP/IP

Earthworm

Smart24a BH BB OBS Others

System Architecture

Earthquake Rapid Report

Earthquake Early Warning

Tsunami Early Warning

Fault Plane Solutions

Earthquake Catalog

File Header

Port Header

Data (4 bytes for 24 bits data)

(Component , Port , Points)

Content Data Type

1 System ID 4 bytes char

2 Year 2 bytes int

3 Milli-second 2 bytes int

4 File length (sec)

2 bytes int

5 Month 1 byte int

6 Day 1 byte int

7 Hour 1 byte int

8 Minute 1 byte int

9 Second 1 byte int

10 Sample Rate 1 byte unsigned int

11 Number of Port

2 bytes int

12 Null (Empty) 6 bytes int

Content Data Type

1 Station 4 bytes char TAP1, HWA ,CHN5, ……

2 Instrument 4 bytes char

FBA, SP, BB

3 Component Order

3 bytes char VNE

4 GPS status 1 byte int 0 ： unlock, 1 ： lock , 2 ： unknown, 3 ： data lost

5 Null (Empty) 2 bytes int Un-used

6 Number of Comp 1 byte int 3

7 Location 1 byte int 1 ： Surface , 2 ： Borehole , 3 ： Ocean Bottom

8 Net Name 4 bytes char

9 Null (Empty) 12 bytes int Un-used

Port Header (32 Bytes each port)File Header (24 bytes)

CWB24 Format

GPS Status

CHY

Integrated CWB Seismic Network

IES-YMS

Acceleration

Short Period

Acceleration

IRIS-JPN

Short Period

Broad Band

IES-BATS

Bore Hole

http://cwbsnbb.cwb.gov.tw/index_en.htm

http://www.cwb.gov.tw/V7e/earthquake/

Thanks for your attention.