Epidemic-Type Aftershock-Sequences (ETAS) model

島內 30公里以上規模大於 5Change Interval 1.5 yrsBackground Interval 4.5 yrs

從臨界轉變的角度理解地震預測技術Theory of critical transitions helps understand seismicity-based earthquake prediction

techniques

中央大學地球科學系暨地球物理研究所 陳建志

1. Compute relative intensity maps: I1= I(x,t0,t1) ; I2= I(x,t0,t2).

2. Normalize them so they have the same statistics with respect to area averages.

3. Define the average Change Map: <I> = <I2 - I1> The average is over all change maps having the same change interval (t1,t2).

4. Define P = {<I> }2, and subtract the area mean to obtain P

5. Color-contour Log10{P} on a map

Time

1973 t0 t1 t2 t3

“Change Interval” “Forecast Interval”

Databegins

x (position)

Schematic: Spatial Cross SectionOf Intensity Map along a Linear Track

P = Probability = {< I >}2

Intensity = I

Intensity Change = I

Quiescence

Activation

I2

I1

Schematic Diagram of PI

LURR Theory

Stress-strain relation of rock materials

X+>X- , Y>1P

R

(∆P)+

(∆P)-

(∆R)-

(∆R)+

Loading

Unloading

(∆P)+

(∆P)-

(∆R)-

(∆R)+

Loading

Unloading

X+=X- , Y=1

0 : number½: Benioff strain1: energy1/3: size (length)2/3: size (area)

地震斷層系統的臨界轉變模型

LURR PI

THANKS

觀測資料與 0327埔里地震關係震央距： 19km觀測資料有反應約在發震 5 秒之後

地震前後差異：井 1 約被抬升 60mV/km井 2 約 60mV/km發震前（ 0303-0306 ）約有 3 秒的相對低頻訊號

惠蓀林場潰壩與大地電場監測實驗場址S

井 1

井 2

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