nori nakata - mit
TRANSCRIPT
![Page 1: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/1.jpg)
Focal mechanisms!
Nori Nakata!Stanford University!
![Page 2: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/2.jpg)
Faulting!
![Page 3: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/3.jpg)
Faulting!N
Dip
Strike
![Page 4: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/4.jpg)
Faulting!
Dip
Strike
Rake
N
![Page 5: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/5.jpg)
Focal mechanism!
Dip
Strike
Rake
N
Strike: 0-360 Dip: 0-90 Rake: 0-360
![Page 6: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/6.jpg)
[s, d, r]=[0,90,0]!
Dip
Strike
Rake
N
![Page 7: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/7.jpg)
[s, d, r]=[0,90,0]!
Dip
Strike
Rake
N
![Page 8: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/8.jpg)
[s, d, r]=[0,60,0]!
Dip
Strike
Rake
N
![Page 9: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/9.jpg)
[s, d, r]=[0,60,0]!
Dip
Strike
Rake
N
![Page 10: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/10.jpg)
[s, d, r]=[0,90-0,0]!90
0 30
60
![Page 11: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/11.jpg)
[s, d, r]=[30,90,0]!
Dip
Strike
Rake
N
![Page 12: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/12.jpg)
[s, d, r]=[30,90,0]!
Dip
Strike
Rake
N
![Page 13: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/13.jpg)
[s, d, r]=[30,60,0]!
Dip
Strike
Rake
N
![Page 14: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/14.jpg)
[s, d, r]=[30,60,0]!
Dip
Strike
Rake
N
![Page 15: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/15.jpg)
[s, d, r]=[0,90,30]!
Dip
Strike
Rake
N
![Page 16: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/16.jpg)
[s, d, r]=[0,90,30]!
Dip
Strike
Rake
N
![Page 17: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/17.jpg)
[s, d, r]=[0,90,60]!
Dip
Strike
Rake
N
![Page 18: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/18.jpg)
[s, d, r]=[0,90,60]!
Dip
Strike
Rake
N
![Page 19: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/19.jpg)
[s, d, r]=[270,30,0]!
Dip
Strike
Rake
N
![Page 20: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/20.jpg)
[s, d, r]=[270,30,0]!
Dip
Strike
Rake
N
![Page 21: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/21.jpg)
[s, d, r]=[30,30,60]!
Dip
Strike
Rake
N
![Page 22: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/22.jpg)
[s, d, r]=[30,30,60]!
Dip
Strike
Rake
N
![Page 23: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/23.jpg)
[s, d, r]=[0,90,0-270]!0
270
120
150
![Page 24: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/24.jpg)
[s, d, r]=[30,90,0-270]!0
270
120
150
![Page 25: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/25.jpg)
[s, d, r]=[30,60,0-270]!0
270
120
150
![Page 26: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/26.jpg)
Are they enough?!
Dip
Strike
Rake
N
![Page 27: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/27.jpg)
Are they enough?!
![Page 28: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/28.jpg)
Moment tensor!
![Page 29: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/29.jpg)
Moment tensor!
[s,d,r]=[0,90,0]
1p2
0
@0 1 01 0 00 0 0
1
A
![Page 30: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/30.jpg)
Moment tensor!0
@0.0566 0 0
0 1.7015 00 0 �1.758
1
A
![Page 31: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/31.jpg)
Moment tensor!0
@0.0566 0 0
0 1.7015 00 0 �1.758
1
A
0
@0 0 00 1.7298 00 0 �1.7298
1
A
0
@0.0566 0 0
0 �0.0283 00 0 0.0283
1
A
0
@�7.4e� 17 0 0
0 �7.4e� 17 00 0 �7.4e� 17
1
A
= + +
![Page 32: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/32.jpg)
Moment tensor!
= + +
![Page 33: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/33.jpg)
Moment magnitude!
Mw =
2
3
(log10 M0 � 9.1)
M0 =1p2
0
@X
ij
M2ij
1
A1/2
![Page 34: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/34.jpg)
![Page 35: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/35.jpg)
Faulting!N
Dip
Strike
![Page 36: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/36.jpg)
Faulting!
Dip
Strike
Rake
N
![Page 37: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/37.jpg)
Faulting!
Dip
Strike
Rake
N
![Page 38: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/38.jpg)
Faulting!
Dip
Strike
Rake
N
Rake = 0 (left) 180 (right) Rake = 90 Rake = 270
![Page 39: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/39.jpg)
Left-lateral strike slip (rake=0)!
Dip
Strike0 60 1209030
90
60
30
![Page 40: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/40.jpg)
Right-lateral strike slip (rake=180)!
Dip
Strike0 60 1209030
90
60
30
![Page 41: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/41.jpg)
Normap-dip slip (rake=270)!
Dip
Strike0 60 1209030
90
60
30
![Page 42: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/42.jpg)
Reverse-dip slip (rake=90)!
Dip
Strike0 60 1209030
90
60
30
![Page 43: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/43.jpg)
Reverse-dip slip (rake=90)!
Dip
Strike0 60 1209030
90
60
30
![Page 44: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/44.jpg)
P and T axes!P: maximum compressive principal stress T: minimum compressive principal stress
T P
v
v
NP1
NP2
![Page 45: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/45.jpg)
Radiation pattern!
Pujol (2003)
![Page 46: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/46.jpg)
Moment tensor!
= + +
![Page 47: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/47.jpg)
Characterize earthquake!
What kind of faulting? Is the dip shallow or steep? Is the mechanism deviatoric? …
![Page 48: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/48.jpg)
Characterize earthquake!What kind of faulting? Is the dip shallow or steep? Is the mechanism deviatoric? What is the horizontal direction of faulting?
[s,d,r]=[30,60,180]
![Page 49: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/49.jpg)
Characterize earthquake![s,d,r]=[30,60,180] What kind of faulting?
Right lateral strike slip Is the dip shallow or steep? Steep Is the mechanism deviatoric? Yes What is the horizontal direction of faulting? 30 degrees from North
![Page 50: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/50.jpg)
Characterize earthquake![s,d,r]=[30,30,60] What kind of faulting?
Is the dip shallow or steep? Is the mechanism deviatoric? What is the horizontal direction of faulting?
![Page 51: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/51.jpg)
Characterize earthquake![s,d,r]=[30,30,60] What kind of faulting?
Mostly reverse-dip slip with some left-lateral strike slip Is the dip shallow or steep? Shallow Is the mechanism deviatoric? Yes What is the horizontal direction of faulting? 30 degrees from North
![Page 52: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/52.jpg)
What kind of faulting? Is the dip shallow or steep (closer to 0 or 90 degrees)? Is the mechanism deviatoric? What is meant by “centroid”?
http://earthquake.usgs.gov/earthquakes/
![Page 53: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/53.jpg)
What kind of faulting? What is the strike? Is the mechanism deviatoric?
![Page 54: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/54.jpg)
What kind of faulting? What is the dip? Is the mechanism deviatoric?
![Page 55: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/55.jpg)
What kind of faulting? Which is the fault plane?
![Page 56: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/56.jpg)
Records!
source
path
site
![Page 57: Nori Nakata - MIT](https://reader031.vdocuments.site/reader031/viewer/2022012417/61726523c35f227979179e44/html5/thumbnails/57.jpg)
Instrument response! 10−4
10−2
100
Ampl
itude
(cm
/s)
a)
KiK−netderivative of Hi−netresponse−corrected Hi−net
10−4
10−2
100
102
Ampl
itude
ratio
b)
without correctionwith correction
10−1 100 1010
180
360
Frequency (Hz)
Phas
e di
ffere
nce
(deg
)
c) without correctionwith correction
Nakata (2013)