Real-time Seismology

Masumi YamadaKyoto University

Jim Mori

Earthquake

Location of aftershocks determined(Mainshock was assumed to be the same place)

Magnitude estimated as 6-7

0min

14min

24min

1994 Northridge EQ

Jim Mori

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

29min

34min

Shaking arrival Tsunami arrival

Mainichi.jp

10sec

55min

Tsunami hight

ProvidingEarthquake Early Warning

needs

ProvidingEarthquake Early Warning

needs

seismometer

Wald(2005) Seismic Stations

San Francis

co

LosAnagel

es

ProvidingEarthquake Early Warning

needs

seismometer

ProvidingEarthquake Early Warning

needs

communicationseismometer

sensor

sensor

sensor

JapanMeteorologic

alAgency

TV

radiocell

phonetown

speaker

provider

train

factory<1sec

ProvidingEarthquake Early Warning

needs

communicationseismometer

ProvidingEarthquake Early Warning

needs

seismologycommunicationseismometer

Kanamori (2005)

Kanamori (2005)

Trade-off: Speed vs Accuracy

8 warnings for M6-7 earthquakes in 3 years

…but 10 times more after March 11, 2011.

M Obs. Pred.

May 8, 2008 7.2 6 + 6 -

July 8, 2008 6.1 5 - 5 -

July 24, 2008 6.8 5 - 6 -

Sep. 11, 2008 7.1 5 +

5 -

Aug. 11, 20096.5 5 + 6 -

Oct. 30, 2009 6.8 5 - 4

Feb. 27, 2010 7.2 6 -

5 -

Mar. 14, 2010 6.7 5 -

5 -

64%64%

17%17%

13%13%

11

11

44

Cell phone

TV

Radio

Announce

Town speaker

Unknown Tohoku earthquakeMarch 11, 2011

“Earthquake occurred off Fukushima.Prepare for strong shaking.”(Japan Meteorological Agency)

Galapagos phone

Smart phone

-NTT OK-Au OK-Softbank NO

-NTT NO-Au OK-Softbank NO (iphone)

vs

with EEW47%

no EEW53%

47% of cell phone

can receive EEW

JMA website, September 2010

How to Use EEW ?

27 bullet trains were stopped without derailments.

- March 11, 2011

2003 Sanriku EQ US $15 million

loss

2005 Miyagi EQ US $200k loss

$600k invested in EEW and structural improvements

OKI SEMICONDUCTOR

Nature.com

Human

Seismometer

iSeismometer

Tsunami Warning

Your idea

Thank youfor your attention.

“Real-time Seismology”Masumi Yamada @Kyoto Univ.

Good! Bad…

3/11 M9 3/12 M6

JMA website

Improve Location Estimation

Real-time Seismology