yih-min wu national taiwan university hiroo kanamori caltech nai-chi hsiao central weather bureau,...
TRANSCRIPT
Yih-Min Wu National Taiwan UniversityHiroo Kanamori CaltechNai-Chi HsiaoCentral Weather Bureau, Taiwan
Topics
P waves method for earthquake early warning
Progress on earthquake early warning system in Taiwan
Earthquake occurs, you may think about
Large earthquake? Cause damage? Is this place safe?
τc & Pd Methods
ττcc average period parameter of the initial three seconds P waves For magnitude determination
PPdd 0.075Hz high pass peak displacement amplitude of the initial three seconds P waves For intensity estimation & damage
identification
- 3 0 3 6 9 1 2 1 5 1 8 2 1
Tim e after P arrival (second)
-12
-8
-4
0
4
8
Dis
pla
ce
me
nt
(cm
)
-20
-10
0
10
20
Ve
loci
ty (
cm
/se
c)
-200
0
200
400
Ac
ce
lera
tio
n (
ga
l)
Pd
PGA
PGV
PGD
c
M w6.6, focal depth 10 kmKnet Station NIG018Epicentral distance 14 km
0.5 cm
Pd threshold warning
Earthquake size could be determined by τc!
4 5 6 7 8
M w
0 . 1
1
1 0
c (
sec)
Taiwan 11 eventsSouthern California 26 eventsJapan 17 events
log (c) = 0.296 M w - 1.716Sdv=0.122, R=0.933
Pd large than 0.5 cm following shakings may cause damage
0.01 0.1 1 10
Pd, Displacem ent (cm )
0.1
1
10
100
Fil
tere
d P
GD
(cm
)
No dam age records (168)No dam age events average (21)Damage records (40)Damage events average (5)
0.5 cm
4 cm
Chi-Chi
PGV could be predicted by Pd and then Shaking Intensity could
be predicted!
0.001 0.01 0.1 1 10Pd (cm)
0 . 1
1
1 0
1 0 0
PG
V (
cm/s
ec)
Taiwan 507 recordsSouthern California 199 recordsJapan 74 records
Linear regression over 780 recordslog(PGV)=0.920 log(Pd) + 1.642SDV = 0.326
Pd for regional EEWfor regional EEW
Pd for magnitude determination
1 0 1 0 0Hypocentral Distance (km)
0.001
0.01
0.1
1
Pd
(cm
)
M7.1M6.75 < M < 64 < M < 5
log(Pd) = -3.463 + 0.729 M - 1.374 log(R), S.D.V. = 0.305
M4.5
M5.5
M6.5
4 5 6 7M
4
5
6
7
MP
d
M Pd = M +- 0.18
Near Source effect!
τc & Pd for damaging event identification!
5 6 7 8
Mw
0.01
0.1
1
10 c
*Pd
(se
c*c
m)
No damage records (168)No damage events average (21)Damage records (40)Damage events average (5)
Damage
No Damage
1999 Chi-Chi
2003Chengkung
1998Reuyli
1999Chiayi
1994Nanoa
Warning could be given within one second after P arrival!
- 2 - 1 0 1 2 3 4Tim e after P arrival (sec)
- 4
- 2
0
2
4
6
- 2
- 1
0
1
2
Dis
pla
cem
ent
(cm
)
2007/03/25 Noto Mw6.7 earthquake
ISK006=7 km
ISK005=19 km
Combination with modern MEMS sensor. Cheaper device may install to every building to give warning within three seconds after P arrival after a large earthquake occurs.
Imports Picks
Scream2ew-BB
PICK_RING
WAVE_RING1
Import_Wave
Import_Smart24 WAVE_RING2
WAVE_RING3
Scn2scnl
WAVE_RING4
Sniffring4eew.c
sniffwave4eew
Share Memory
TcPd.c
Report 200808_evts.txt
Earthworm
sniffwave4eew
Sniffwave4eew.c
SimuSac.cHistorical SAC Records
Iwate earthquake2008/06/14 08:43:45.36 Lat.=39.0298Long.=140.8807 Depth =7.77 kmJMA magnitude 7.2
4 stations6.8 sec after38.9905140.8262 5.65 kmMpd=7.45Mtc=7.72
7 stations7.4 sec after39.0804140.9413 4.38 kmMpd=7.10Mtc=7.53
11 stations8.3 sec after39.0393140.8726 13.92kmMpd=7.29Mtc=7.30
Progress on earthquake early warning system in Taiwan
Real-time strong-motion networkAccelerometer - 102 stations (20km averaged
spacing) 16 bits resolution ± 2g Max. amplitude
Telemetry - Real-time data stream (RTD) 4.8K dedicated telephone
line Sampling rate 50 sps 0.2 sec averaged delay
Data processing - Taipei data center
Windows-based workstation
Real-time strong-motion networkAccelerometer - 102 stations (20km averaged
spacing) 16 bits resolution ± 2g Max. amplitude
Telemetry - Real-time data stream (RTD) 4.8K dedicated telephone
line Sampling rate 50 sps 0.2 sec averaged delay
Data processing - Taipei data center
Windows-based workstation
Virtual sub-network approach
29
Performances for VSN
0.28
~17 sec
5.46 6.41 km
4.66 4.73 km
30
Pd discriminator
3 sec P wave
31
Magnitude estimationc
max
p M
Network triggered
Compute Pd
Pd > 0.1Estimate M
from
M > 6.0Create
shakemap
yes
M
VSN algorithmfrom coming signals
yes
M 7.1
2002/3/31 M 7.0Offshore Hualien earthquake
Network triggered
Compute Pd
Pd > 0.1Estimate M
from
M > 6.0Create
shakemap
yes
M
VSN algorithmfrom coming signals
yes
M 6.4
2006/4/1 M 6.5Taitung earthquake
34
New proposed EEW system
All seismographs installed by CWB are included for EEW evaluation
Use the Earthworm as the platform of different seismic data format integration
Both VSN and P waves methods
c
35
CWB seismographic network
New established stations
36
Preliminary test for new system
0.48 0.34
12.01 13.01 km
20.2 4.9 sec
37
Promotion plan in Taiwan Establish the
promotion mechanismand policy
Construct the prototype systems and testing
Launch formal systems and deploy applications
2011 2012 20132009 2010 2014 2015
PolicyRatification
TechnologyDevelopment
ApplicationDeployment
Development and integrationof key technology
Concentrated Investment
Establish associated measures for application
System integration and product certificationTechnology transfer and industry promotion
Education, training, and drillsRelated regulation draft
First stage
Second stage
2016
• Regional EEW technology• On-site EEW technology• Evaluation of communication
channels• Investigation of user demands
School: Regional EEW, On-site EEW, Alarms, Broadcasting system
Emergency response institutions: Regional EEW, Alarms, Broadcasting system
Transportation system: Regional EEW, On-site EEW, Alarms, Broadcasting system, Automatic control
Apply the regional EEW systemDevelop the on-site EEW system
Develop the regional EEW and on-site EEW systems at the same time
Hospital: Regional EEW, On-site EEW, Alarms, Broadcasting system, Automatic control
Elevator: Regional EEW, On-site EEW, Automatic controlBuilding: Regional EEW, On-site EEW, Alarms,
Broadcasting system, Automatic controlHigh-tech factory: Regional EEW, On-site EEW, Alarms,
Broadcasting system, Automatic control
Integration of regional and on-site EEW systems
Thanks for your attention!