Yan Y. Kagan
Dept. Earth and Space Sciences, UCLA, Los Angeles,
CA 90095-1567, ykagan@ucla.edu,
http://scec.ess.ucla.edu/ykagan.html
TIME DEPENDENT EARTHQUAKE
PROBABILITIES
http://moho.ess.ucla.edu/~kagan/Arrowhead.ppt
Lake Arrowhead, WGCEP, March 6-8, 2007
(1)
Kagan, Y. Y. and D. D. Jackson, 1999. Worldwide
doublets of large shallow earthquakes, Bull. Seismol.
Soc. Amer., 89, 1147-1155.
Kagan, Y. Y., and
H. Houston,
2005. Relation
between
mainshock
rupture process
and Omori's law
for aftershock
moment release
rate, Geophys. J.
Int., 163(3),
1039-1048
Another view (WPGM Meeting 2000,
S42B-01)
•
HR: 1400h
AN: S42B-01
TI: The 1978 Kurile Islands Earthquake Doublet: No Conflict With Quasi-Periodic Recurrence Models
AU: * Hurukawa, N
EM: hurukawa@kenken.go.jp
AF: U. S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 United States
AU: Ellsworth, W L
EM: ellsworth@usgs.gov
AF: U. S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 United States
AB: The M$_{w}$ 7.5 and 7.6 1978 Kurile Islands earthquakes of March 23 and 24, 1978 and their M$_{w}$ 7.0 foreshock
are low-angle thrust events that occurred on the boundary between the Pacific and North American plates. Kagan and Jackson
(BSSA, 1999) proposed that the rupture areas of the two main shocks have significant overlap because the Harvard catalog
centroids for the main shocks are only 25 km apart, and the one day aftershocks listed in the PDE bulletin have significant
overlap. Based on this and similar earthquake pairings in the Harvard catalog, they concluded that a power-law recurrence
model is much better than quasi-periodic recurrence models on which the seismic gap model is based. We test the hypothesis
that the Kurile Islands earthquakes ruptured the same area by re-determining the centroid locations using cross correlation
methods, and relocating the foreshocks, main shocks and aftershocks using joint hypocenter determination methods.
Differential travel times of long period body waves (f $<=$ 0.05 Hz) show that the centroids of the two main shocks are
separated by 57 $\pm$ 5 km along the strike direction of the trench. A centroid separation of this amount implies little or no
overlap of the rupture areas if the stress drop is about 3 MPa or greater. Hypocenters for the sequence were determined using
P-wave arrival times reported by the International Seismological Center. Although the aftershock areas of the two main
shocks overlap, the overlap area is where the intense foreshock activity, including the M$_{w}$ 7.0, occurred. If we exclude
earthquakes that occurred in the foreshock area, there is no overlap of the one day aftershock areas of the two main shocks.
The centroids of the three large events are located within their respective aftershock zones. We further test the relation
between the two main shocks and the largest foreshock by locating correlative peaks in the broad band (f $<=$ 0.5 Hz)
velocity P waveforms. These presumed areas of moment release for the three events are clearly separated from each other and
coincide with their respective aftershock areas. Therefore, we can conclude that the source areas of the M$_{w}$ 7.5 and 7.6
events that form this doublet do not have significant overlap. The occurrence of this doublet does not conflict with the basic
tenets of the elastic rebound model of earthquake occurrence or seismic gap theory as applied to the Kurile trench.
Another view (WPGM Meeting 2000,
S42B-01)
• Hurukawa, N. and W. L. Ellsworth, 2000. The
1978 Kurile Islands Earthquake Doublet: No
Conflict With Quasi-Periodic Recurrence
Models, abstract at 2000 Western Pacific
Geophysics Meeting, S42B-01
… Therefore, we can conclude that the source areas of the
Mw 7.5 and 7.6 events that form this doublet do not have
significant overlap. The occurrence of this doublet does
not conflict with the basic tenets of the elastic rebound
model of earthquake occurrence or seismic gap theory as
applied to the Kurile trench.
Rules of the game
• ALL pairs of shallow earthquakes
M>=10^20.25 Nm (Mw>=7.5) with centroid
distance less than 100 km from the CMT
catalog have been processed (no pre-selection).
• CMT solutions for earthquakes are obtained
using uniform assumptions and interpretation
methods. The solutions are independent from
our analysis.
• The results are easily reproducible.
Kagan, Y. Y. and D. D. Jackson, 1999. Worldwide
doublets of large shallow earthquakes, Bull. Seismol.
Soc. Amer., 89, 1147-1155.
First earthquake
N
1*
2*
3*
4*
5*
6
7
8*
9*
10*
11*
12
13
14
15
16
17
Year Mo Da
1978
1980
1980
1980
1983
1983
1983
1984
1985
1987
1990
1995
2000
2000
2000
2001
2006
3
7
7
7
3
3
3
2
9
3
4
8
11
11
11
6
11
23
8
8
17
18
18
18
7
19
5
18
16
16
16
16
23
15
Second earthquake
Lat
Long
44.1 149.3
-12.9 166.2
-12.9 166.2
-12.4 165.9
-4.9 153.3
-4.9 153.3
-4.9 153.3
-9.8 160.4
17.9 -102.0
-24.4 -70.9
1.3 123.3
-5.5 153.6
-4.6 152.8
-4.6 152.8
-5.0 153.2
-17.3 -72.7
46.8 154.3
De Mag
Year Mo Da
28
44
44
34
70
70
70
22
21
42
33
46
24
24
31
30
13
1978
1980
1997
1997
1995
2000
2000
1988
1985
1995
1991
2000
2000
2000
2000
2001
2007
7.6
7.5
7.5
7.8
7.8
7.8
7.8
7.6
8.0
7.6
7.7
7.8
8.1
8.1
7.9
8.5
8.4
3
7
4
4
8
11
11
8
9
7
6
11
11
11
11
7
1
24
17
21
21
16
16
16
10
21
30
20
16
16
17
17
7
13
Difference
Lat
Long
44.2 149.0
-12.4 165.9
-13.2 166.2
-13.2 166.2
-5.5 153.6
-4.6 152.8
-5.0 153.2
-10.5 160.8
17.6 -101.4
-24.2 -70.7
1.0 123.2
-5.0 153.2
-5.0 153.2
-5.3 152.3
-5.3 152.3
-17.5 -72.4
46.2 154.8
1st mechan.
2nd mechan. (L1+L2)
De Mag
Dist
DM Angle Time_Diff Dip Str Dp Str Dip Str Dp Str /Dist
T-axis P-axis T-axis P-axis (2-3)
31
34
51
51
46
24
31
16
21
29
15
31
31
17
17
25
12
24.9
61.7
33.0
91.7
83.0
83.3
47.2
84.9
71.2
32.9
37.4
76.0
67.4
92.6
96.4
33.8
73.2
0
-2
-1
0
0
-2
0
0
4
-4
1
0
2
2
0
8
2
7.6
7.8
7.8
7.8
7.8
8.1
7.9
7.6
7.6
8.1
7.6
7.9
7.9
7.8
7.8
7.7
8.2
7.2
18.4
42.5
35.1
26.3
71.9
91.4
50.2
14.3
7.4
28.7
74.5
88.5
88.5
13.9
8.0
80.1
1.6892
8.8496
6130.5302
6121.6806
4534.0569
6452.8260
6452.9421
1645.2952
1.5133
3068.8296
427.6524
1918.8852
0.1161
1.6713
1.5553
13.5449
58.7143
56
81
81
74
68
68
68
51
62
66
66
86
33
33
60
60
60
312
320
320
49
150
150
150
130
9
73
135
259
181
181
339
80
302
34
4
4
14
0
0
0
20
28
23
17
3
29
29
30
29
30
132
75
75
253
59
59
59
247
199
270
0
48
292
292
160
242
123
63
74
57
57
86
33
60
61
62
67
52
60
60
65
65
55
10
309
49
131
131
259
181
339
35
33
90
185
339
339
7
7
86
150
27
14
15
15
3
29
30
28
28
23
38
30
30
22
22
33
67
131
253
245
245
48
292
160
235
209
267
8
160
160
160
160
248
264
2.33
1.07
1.95
0.86
0.96
1.26
1.84
0.69
1.27
2.82
1.64
1.14
1.66
1.17
0.94
4.72
2.50
* -- this pair is included in Table 1 by Kagan and Jackson, BSSA, 89(5), 1999.
The last column is the ratio of earthquake focal zone sizes to twice their distance, see equations (2-3) in Kagan and Jackson, 1999.
7 pairs with zero magnitude difference, 4 pairs -- foreshocks, 6 pairs – aftershocks.
Kagan, Y. Y. and D. D. Jackson, 1999. Worldwide
doublets of large shallow earthquakes, Bull. Seismol.
Soc. Amer., 89, 1147-1155.
#
1*
2*
3*
4*
5*
6
7
8*
9*
10*
11*
12
13
14
15
16
17
First Quake
Year Mon
1978 3
1980 7
1980 7
1980 7
1983 3
1983 3
1983 3
1984 2
1985 9
1987 3
1990 4
1995 8
2000 11
2000 11
2000 11
2001 6
2006 11
Day
23
8
8
17
18
18
18
7
19
5
18
16
16
16
16
23
15
Lat
44.1
-12.9
-12.9
-12.4
-4.9
-4.9
-4.9
-9.8
17.9
-24.4
1.3
-5.5
-4.6
-4.6
-5.0
-17.3
46.8
Lon Dept Mag
149.3 28 7.6
166.2 44 7.5
166.2 44 7.5
165.9 34 7.8
153.3 70 7.8
153.3 70 7.8
153.3 70 7.8
160.4 22 7.6
-102.0 21 8.0
-70.9
42 7.6
123.3 33 7.7
153.6 46 7.8
152.8 24 8.1
152.8 24 8.1
153.2 31 7.9
-72.7
30 8.5
154.3 13 8.4
Second Quake
Year Mon Day
1978 3 24
1980 7 17
1997 4 21
1997 4 21
1995 8 16
2000 11 16
2000 11 16
1988 8 10
1985 9 21
1995 7 30
1991 6 20
2000 11 16
2000 11 16
2000 11 17
2000 11 17
2001 7
7
2007 1 13
Lat
44.2
-12.4
-13.2
-13.2
-5.5
-4.6
-5.0
-10.5
17.6
-24.2
1.0
-5.0
-5.0
-5.3
-5.3
-17.5
46.2
Lon Dept Mag
149.0 31 7.6
165.9 34 7.8
166.2 51 7.8
166.2 51 7.8
153.6 46 7.8
152.8 24 8.1
153.2 31 7.9
160.8 16 7.6
-101.4 21 7.6
-70.7
29 8.1
123.2 15 7.6
153.2 31 7.9
153.2 31 7.9
152.3 17 7.8
152.3 17 7.8
-72.4
25 7.7
154.8 12 8.2
Comparisons
Dist dMag Angle
24.9
0.0
7.2
61.7 -0.2 18.4
33.0 -0.1 42.5
91.7
0.0 35.1
83.0
0.0 26.3
83.3 -0.2 71.9
47.2
0.0 91.4
84.9
0.0 50.2
71.2
0.4 14.3
32.9 -0.4 7.4
37.4
0.1 28.7
76.0
0.0 74.5
67.4
0.2 88.5
92.6
0.2 88.5
96.4
0.0 13.9
33.8
0.8
8
73.2
0.2 80.1
dTime
1.7
8.8
6131
6122
4534
6453
6453
1645
1.5
3069
428
1919
0.1
1.7
1.6
14
59
CMT catalog (Peru 2001 M8.4 eq.)
M062301E 06/23/01 20:33:14.1 -16.26 -73.64 33.06.78.2NEAR COAST OF PERU
PDE BW: 0 0 0 MW:68170 135 DT= 69.2 0.1 -17.28 0.01 -72.71 0.01 29.6 0.4
DUR43.2 EX 28 2.24 0.01 -0.55 0.01 -1.70 0.01 1.34 0.05 -3.73 0.07 1.44 0.01
4.53 60 80 0.29 8 336 -4.82 29 242 4.67 310 18 63 159 74 98
C070701F 07/07/01 09:38:43.5 -17.54 -72.08 33.06.67.3NEAR COAST OF PERU
PDE BW:63158 45 MW:60136 135 DT= 18.3 0.1 -17.45 0.01 -72.45 0.01 25.0 0.4
DUR14.0 EX 27 1.14 0.01 -0.21 0.01 -0.93 0.01 0.68 0.03 -2.85 0.05 0.77 0.00
3.14 55 86 0.13 9 344 -3.26 33 248 3.20 306 14 52 165 79 99
-16
-17
-18
-74
-73
-72
Bilek, S. L., and L. J. Ruff,
2002. Analysis of the 23 June
2001 Mw = 8.4 Peru
underthrusting
earthquake and its
aftershocks, Geophys. Res.
Lett., 29(20), 1960,
doi:10.1029/2002GL015543.
Robinson,
D.P., S. Das,
and A.B.
Watts, 2006.
Earthquake
rupture stalled
by a
subducting
fracture zone,
Science, 312,
1203-1205.
Fig. S1. Aftershocks, relocated for this study, are shown for the 24 hours following the main earthquake. The main shock (red
star), together with the centroid-moment tensor solution recalculated for this study (see below), is shown. The ISC reports
249 aftershocks in this time period. We relocated 233 of these successfully, with 155 having 90% confidence ellipse < 30 km
(shown in grey). Relocated epicenters are shown as circles, the size of the circle scaling with magnitude and color coded in
depth (< 50 km in red, between 50 to 150 km in green).
Fig. S2. Same as Fig. S1
but for the 6 month period
following the main shock
with the addition of
earthquakes > 150 km
depth colored blue. The
ISC reports 967
aftershocks in this time
period, 28 of which were
large enough to have
CMT solutions. We
relocated all earthquakes
with CMT solutions and
891 of the smaller
earthquakes successfully,
551 of which had 90%
confidence error ellipses <
30 km.
Robinson, D.P., S.
Das, and A.B. Watts,
2006.
Earthquake rupture
stalled by a
subducting fracture
zone, Science, 312,
1203-1205.
(2)
Kagan, Y. Y., 2000. Temporal correlations of earthquake focal
mechanisms, Geophys. J. Int., 143, 881-897.
(3)
Earthquake Scaling: M ~ L3
• It is commonly believed that the earthquake
focal size scaling (i.e., dependence of the size
on seismic moment) is different for events of
various focal mechanisms.
• In particular, strike-slip earthquakes which
occur on vertical faults are considered to have
two power-law dependencies: break occurring
around 15-20 km (corresponding to M6 event).
• Long debate between Scholz and Romanowicz.
Kagan, Y. Y., 2002. Aftershock zone scaling,
Bull. Seismol. Soc. Amer., 92,
641-655.
• Update for 1977-2006 (CMT catalog – focal
mechanisms; PDE catalog – aftershock zones,
approximated by two-dimensional Gaussian
distribution).
• We obtain for all earthquakes (disregarding their
focal mechanism) the same scaling relation:
scalar moment proportional to the cube of
3
aftershock zone length M  L
(4)
Best Available Science?
• What is the SCIENTIFIC approach? Karl
Popper’s answer (1980): a hypothesis (model)
which is falsifiable, testable.
• Almost all models employed in earthquake
seismology do not satisfy this criterion – their
predictions are not testable, at least in
reasonable time, thus they are not yet science.
Characteristic Earthquakes,
Seismic Gaps, Quasi-periodicity
• Schwartz and Coppersmith (1984) proposed
the characteristic model. McCann et al. (1979)
and Nishenko (1991) formulated testable
hypothesis -- about 100 zones in circumPacific belt. Kagan & Jackson (JGR, 1991,
1995), and Rong et al. (JGR, 2003) tested
these predictions and found that earthquakes
after 1979 or 1989, respectively, do not
support the model.
McCann et
al. (1979)
The map of
seismic gap
zones -compare
Sumatra
2004
rupture.
Kagan &
Jackson
(1991)
tested the
map – the
result is
negative.
Characteristic Earthquakes,
Seismic gaps, Quasi-periodicity
Bakun & Lindh (Science, 1985) -- Parkfield
prediction, 95% probability of M6 event in
1985-1993. No earthquake occurred. In 2004
M6 event in the Parkfield area. Only few of the
predicted features were observed. Bakun et al.
(Nature, 2005) review the experiment results -no new prediction is issued. See Jackson &
Kagan (2006) http://scec.ess.ucla.edu/
~ykagan/parkf2004_index.html.
Characteristic Earthquakes,
Seismic Gaps, Quasi-periodicity
• Chris Scholz in the 1999 Nature Debate:
In their [Kagan & Jackson] more recent study,
they found, in contrast, less events than
predicted by Nishenko [1991]. But here the
failure was in a different part of the physics:
the assumptions of recurrence times made by
Nishenko. These recurrence times are based on
very little data, no theory, and are
unquestionably suspect.
Characteristic Earthquakes,
Seismic Gaps, Quasi-periodicity
• Bakun et al., Nature, 2005:
(The characteristic earthquake model can also
be tested using global data sets. Kagan and
Jackson [1995] concluded that too few of
Nishenko’s [1991] predicted gap-filling
circum-Pacific earthquakes occurred in the
first 5 yr.)
Characteristic Earthquakes,
Seismic Gaps, Quasi-periodicity
• Despite the failure of these predictions, this
model was employed in San Francisco Bay
area (Working Group, 2003) -- "there is a 0.62
[0.38--0.85] probability of a major, damaging
[M > 6.7] earthquake striking the greater San
Francisco Bay Region over the next 30 years
(2002--2031)."
Characteristic Earthquakes,
Seismic Gaps, Quasi-periodicity
• Stark and Freedman (2003) argue that the
probabilities defined in such a prediction are
meaningless because they cannot be validated.
They suggest that the reader "should largely
ignore the USGS probability forecast."
• See more detail in Jackson & Kagan (2006)
http://scec.ess.ucla.edu/~ykagan/parkf2004_in
dex.html
Characteristic Earthquakes,
Seismic Gaps, Quasi-periodicity
• Thomas Kuhn (1965) questioned how one can
distinguish scientific and non-scientific
predictions. As an example, he used astronomy
versus astrology -- both issue predictions that
sometimes fail. However, astronomers learn
from these mistakes, modify and update their
models, whereas astrologers do not.
What needs to be done?
• Bill Ellsworth (2007, January Swiss RE
meeting): HEROIC effort to quantitatively test
quasi-periodic, characteristic earthquake model
(following McCann et al., 1979; Nishenko,
1989).
(5)
Seismicity Model
Most of earthquake fault models use planar
block boundary geometry. Incompatibility
problem is circumvented because of flat plate
boundaries. Real earthquake faults always
contain triple junctions; further deformation is
impossible without creating new fractures and
rotational defects (disclinations).
Y. Kagan (GJRAS, 1982), G. King (PAGEOPH,
1983; 1986).
Example of geometric incompatibility near fault junction. Corners A and
C are either converging and would overlap or are diverging; this
indicates that the movement cannot be realized without the change of the
fault geometry (Gabrielov, A., Keilis-Borok, V., and Jackson, D. D.,
1996. Geometric incompatibility in a fault system, P. Natl. Acad. Sci.
USA, 93, 3838-3842).
END