1.Earthquake Early Warning System. Japan Meteorological Agency

Transcription

1 1 st Process 1.Earthquake Early Warning System Estimation Estimation of of Hypocenter, Hypocenter, Magnitude Magnitude and and Seismic Seismic Intensity Intensity Dissemination Dissemination Present Status Future Plan Shin ya TSUKADA 1 st Information Japan Meteorological Agency

2 1. Hypocenter estimation 1) Single station method 2) Network method 2. Magnitude estimation 3. Seismic intensity estimation 2min 3min 5-7min Earthquake EEW Seismic Intensity Earthquake Information Tsunami Warning

3 Extraction of waveform character -> A & B B B near -- Delta -- far 1 sec Delta abs. & log fit Bt*exp(-At) P onset

4 Territory status 1st station Inland Station Coastal Station Perpendicular bisector between 1st and adjacent station Inland Station 2 stations Perpendicular bisector between adjacent stations Updated every time dead or alive at about 200 stations Coastal Station Using B-delta method 1st Station Each Centroid Critical Angle

5 3 to 5 stations Region limitation of grid search Station that is not detected P-arrival 1st 2nd 3rd 4th Perpendicular bisector between detected station and not detected station at every 0.1 degree horizontally and 10km vertically

6 More than 2 stations Integrate from Jun Use Hi-net (NIED)

7 M P Formula S Formula Holding Magnitude Event magnitude is average of station magnitude False reduction P max. S max. t Maximum Displacement Amplitude P onset S onset Not to mistake S-wave amplitude for P-wave amplitude because of hypocentral error P Formula M = logd max + logr R S Formula M = logd max + logr R Dmax : 3-dimensional vector summation of displacement R: hypocentral distance

8 D 3) Conversion of maximum velocity amplitude to JMA seismic intensity Midorikawa, ) multiplying amplification coefficient Matsuoka and Midorikawa, ) Maximum velocity amplitude at the engineering bedrock = f (M,X,D) Si and Midorikawa, 1999 Miyagi-Ken Hokubu EQ 38.5N,141.2E,10km,M6.2 First Information: 3 seconds After P onset

9 Dissemination Criteria Over 3.5 for magnitude and 3 for JMA seismic intensity scale. 1) The first warning The result using 2seconds waveform or Onsite warning over 100cm/s/s (without hypocenter information) 2) The cancel report There is no following P phase detection at the closest station. 3) The updated warnings Threshold Change 0.2 degrees for latitude and longitude, 20km for hypocentral depth, +0.5, -1.0 for event magnitude and maximum seismic intensity. Fixed timing 10,30,50seconds after detection 4) The final warning when the pre-set time has passed after the first detection of the P phase, or when the estimated magnitude value converged.

10 11:46:26 Origin Time 11:46:41 First Detection 11:46:45 1st EEW Hypocenter,Magnitude,and Seismic Intensity 11:46:45 2nd EEW updated EEW... 11:47:51 Final EEW(8th) 11:48 Seismic Intensity Information 11:50 Tsunami Advisory 11:54 Earthquake Information 12:12 13cm tsunami height (at Ayukawa) 13:15 Tsunami Cancellation Kawasaki (6L): 22 sec. Ishinomaki (5U): 10 sec. Tsunami advisory epicenter Sendai (5U): 16 sec. JMASeismic Intensity 7 6U 6L 5U 5L 4

11 2000- Development of EEW technology 2004/2/25 Start of trial dissemination (For Kanto-Tokai-Nankai area) 2005/3/28 Expand of trial dissemination area (For Hokkaido-Tohoku area) 2005/6 Integrate of Not Yet Arrived Data Method algorithm developed at NIED 2006/3/31 Expand of trial dissemination area (For whole country) 855 times ( including 26 times false alarms)

12 Odakyu Electric Railway Furnish from Prof. Motosaka JEITA KAJIMA CORPORATION

13 JMA started official service for limited fields of application in August. As of November 2, 2006

14 * JMA have been issuing Earthquake Early Warning on a trial basis from Feb to Jul times ( including 26 times false alarms) * JMA started official service for limited fields of application in August. We are promoting public campaigns for better understanding of the EEW, and are going to disseminate EEW publicly in the coming year.

15 Thank you for your attention!