How to Prepare for a Strong Shaking? - ndmindia.nic.in · Masumi Yamada, Kyoto University How to...
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Masumi Yamada, Kyoto University How to Prepare for a Strong Shaking? Earthquake Early Warning in Japan
Transcript of How to Prepare for a Strong Shaking? - ndmindia.nic.in · Masumi Yamada, Kyoto University How to...
Masumi Yamada, Kyoto University
How to Preparefor a Strong Shaking?
Earthquake Early Warning in Japan
2011 Tohoku EQEarthquake
P-wave detected
Location and Magnitude determinedEarthquake Early Warning issued
Observed Seismic Intensity reported
Tsunami Warning issued
0sec
19sec
27sec
3min
3.5min
27 bullet trains were stopped without derailments.
- March 11, 2011
Damage to bullet trains・ Damage to cable column 540・ Damage to cable 470・ Damage to column 100・ Damage to rail track 20
AERA Mook 震災と鉄道全記録
ProvidingEarthquake Early Warning
needs
ProvidingEarthquake Early Warning
needs
infrastructure
Seismic Stations
http://iisee.kenken.go.jp/net/shiva/update/India(IMD)0619.pdf
300km
ProvidingEarthquake Early Warning
needs
infrastructure
ProvidingEarthquake Early Warning
needs
infrastructure information technology
sensor
sensor
sensor
JapanMeteorologic
alAgency
TV
radiocell
phonetown
speaker
provider
train
factory<1sec
“Earthquake occurred off Fukushima.Prepare for strong shaking.”(Japan Meteorological Agency)
http://www.data.jma.go.jp/svd/eqev/data/study-panel/eew-hyoka/05/shiryou4-1.pdf
5th meeting of EEW improvement
Automated Responses to EEW
0 10 20 30 40 50 60
Public announcement
Elevator: emergency stop
Warning (alarm)
Warning (flashing lights)
Show alert on monitors
Secure evacuation route
Control machine
Other
Nothing
ProvidingEarthquake Early Warning
needs
infrastructure information technology
ProvidingEarthquake Early Warning
needs
seismologyinformation technology
infrastructure
Kanamori (2005)
How to estimate shaking?
http://www.seisvol.kishou.go.jp/eq/EEW/Meeting_HYOUKA/t02/index.html
Step1: Estimate location from P-
arrival times
Step2: Estimate Mag. from
displacement (Ad) & R
Step3: Estimate Shaking intensity
from M & R
log10PGV=0.58Mw+0.0038D – 1.29 – log10 (R+0.0028*100.5Mw) – 0.002Rlog10ARV =1.83 – 0.66 log10AVS30SI = 2.68 +1.72log10 (PGV*ARV)
Threshold of shaking to give EEW
The intensity is computed from acceleration waveforms.
5- 5+ 6- 6+ 7
0 1 2 3 4
(JMA Website)
2001 Gujarat Earthquake
Create Dataset | displacement amp.
Amplitude σ=±30%Vp and Vs σ=±10%
Location Estimation
Time History of Warnings
Earthquake
1st P-wave triggered @Bhuj
2nd P-wave triggered @ BhavnagarLocation and Magnitude determined
0sec
10sec
40sec
Time History of Warnings
Bhuj
Bhavnagar
Time History of Warnings
Earthquake
1st P-wave triggered @Bhuj
2nd P-wave triggered @ BhavnagarLocation and Magnitude determined
3nd P-wave triggered @ JaisalmerLocation error <10km
0sec
10sec
40sec
60sec
Time History of Warnings
Bhuj
Bhavnagar
Jaisalmer
Japanese EEWFacts and Figures
http://www.data.jma.go.jp/svd/eqev/data/study-panel/eew-hyoka/06/shiryou1.pdf
6th meeting of EEW improvement
Number of warnings
0 20 40 60 80 100
93%
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
44%
Accuracy
False alarm for 2011 Tohoku aftershock
False alarm for 2011 Tohoku aftershock
2013 False alarm
EEW M7.8Reality M2.3
M2.3
Disconnection of data
Noise
M7.8
http://www.data.jma.go.jp/svd/eqev/data/study-panel/eew-hyoka/05/shiryou3-2.pdf
Feedback on the False AlarmUpset
Not upset, but concerned
No choice
Unconcerned
Disinterested
Other
0 10 20 30 40
3%
28%
40%
5th meeting of EEW improvement
Summary
Earthquake Early Warning System needs:Infrastructure
InformationTechnology
Seismology Education× × ×
Examples:2001 Gujarat earthquake in India2011 Tohoku earthquake in Japan2013 False alarm in Japan
Problem1 : Underestimation
http://www.natureasia.com/japan/nature/specials/earthquake/nature_comment_051211-4.php
7070Warnings
AfterTohoku
Problem2 : False Alarms
http://www.jma.go.jp/jma/press/1104/28b/eew_hyouka_2.pdf
BeforeTohoku 1717
Warnings
55Exp.-Obs. ≧ 2
4444Intensity Error (Exp.-
Obs.)≧ 2
12123232multiple events others
Failure of Hypocenter Relocation
Good! Bad…
3/11 M9 3/12 M6
JMA website
Current Approach
Shake!
Shake!
Our Approach
Shake!
Shake!
No shake
No shake
No shake
7070Warnings
AfterTohoku
Performances
http://www.jma.go.jp/jma/press/1104/28b/eew_hyouka_2.pdf
BeforeTohoku 1717
Warnings
55Exp.-Obs. ≧ 2
4444Intensity Error (Exp.-
Obs.)≧ 2
44 2626This Study
