277- Megathrust Earthquakes
Fall Quarter 2007
Instructor: Jean-Philippe Avouac
Fridays, 10:00-11:30pm, + 2 Wednesdays, 2:00-3:30,
Location: Gutenberg Library
In the wake of the recent large earthquakes in Sumatra and Peru,
we will discuss megathrust earthquakes. Based on the review of
the literature (see references below), we will try to identify
the key factors that might control the seismic potential of subduction
zone and the characteristics of large subduction earthquakes. During
the first seminar, the instructor will discuss observations of
interseismic and co-seismic strain along the Sumatra subduction
zone. After that introductory seminar we will review the literature
(see references below), each week being devoted to a new topic.
We will in particular discuss the following points:
- Is there any regularity or systematics in the way a particular
segment of subduction zone ruptures in successive earthquakes?
- How does the portion of a megathrust that is locked during the
interseismic period compares with the rupture area of large earthquakes?
- How does co-seismic slip compares with slip deficit accumulated
during the interseismic period?
- How variable is 'coupling' along the megathrust, both in time
- Correlation of earthquake size and rupture area to subduction
At the end of the seminar series we will come back to the
discussion of Sumatra to see how the observations made there
contrast with what has already been described in the literature,
and what inference can be made regarding the 'seismic cycle' on
We will be meeting once a week in the Gutenberg Library, generally
on Fridays from 10:00 pm to 11:30 pm (see schedule below).The instructor
will give the introductory lecture. Each student will be in charge
of presenting one or two topics to the group over the 10 weeks
course of the seminar. Each student will be asked to interact with
the instructor to prepare the presentation, at least one week ahead
of time. This is important to make it sure that the message is
well conveyed to the group and that the basic concepts necessary
to make the topic accessible to the audience are reviewed during
the presentation. Each week, we will pick one key paper that each
student is expected to have read ahead of time. The information
will be given the week before the presentation.
The ppt presentations, readings and additional papers are available
on JPA ftp site.
Friday, October 8
Topic: Interseismic strain accumulation co-seismic strain release
on the Sumatra Megathrust. This introductory lecture will introduce
the key questions to be discussed later during the seminar series.
Speaker: Jean-Philippe Avouac
Reading : [Thatcher, 1990]
Some references on Sumatra :
[Ammon, et al., 2005; Briggs, et al., 2006; Chlieh,
et al., 2005; Chlieh, et al., 2007; Hsu, et al.,
2006; Konca, et al., 2007; Lay, et al., 2005; Meltzner,
et al., 2006; Natawidjaja, et al., 2004; Natawidjaja,
et al., 2006; Newcomb and McCann, 1987; Sieh,
et al., 1999; Simoes, et al., 2004]
Friday, October 15
Topic : The rupture process of large subduction earthquakes The
asperity model and the slip-pulse model.
Speakers : Yoshi
Readings : [Aki, 1984]
[Dmowska and Lovison, 1992; Heaton, 1990; Igarashi,
et al., 2003; Lay, et al., 1982; Mikumo, et al.,
1998; Park and Mori, 2007; Schwartz and Ruff,
1987; Yagi, et al., 2001]
Friday, October 26
Wednesday, October 31(2:00-3:30)
Topic : Are asperities and barriers long-lived or short-lived features?
Speakers : Ravi Kanda
Reading : [Wells, et al., 2003]
[Kodaira, et al., 2006; Kodaira, et al., 2000; Llenos
and McGuire, 2007; Park and Mori, 2007; Song
and Simons, 2003]
Friday, November 2
Topic : The time predictable and slip predictable models. How ‘regular’ is
the ‘seismic cycle’? How valid is the seismic gap hypothesis?
Speaker : Belle
Readings : [Shimazaki and Nakata, 1980]
[Cisternas, et al., 2005; Kagan and Jackson,
1991; Schwartz, 1999; Shimazaki and Nakata, 1980; Sykes
and Menke, 2006; Thatcher, 1984]
Friday, November 9
Topic : ‘Seismic coupling’ and the depth distribution
of earthquakes along subduction zone.
Speaker : Carl
Readings : [Pacheco, et al., 1993]
[Igarashi, et al., 2001; Nakanishi, et al., 2004; Ruff
and Kanamori, 1983; Tichelaar and Ruff, 1993]
Friday, November 16
Wednesday, November 21 (2:00-3:30)
Topic: ‘Geodetic coupling’. How variable is 'geodetic
coupling' along the megathrust, both in time and space? How does
it compare to ‘seismic coupling’?
Speakers : Ting
Reading : [Burgmann, et al., 2005; Suwa, et al.,
Additional references: [Chlieh, et al., 2004; Cross
and Freymueller, 2007; Fournier and Freymueller,
2007; Freymueller, et al., 2000; Mazzotti, et al.,
1999; Nishimura, et al., 2004; Taylor, et al.,
1996; Wallace and Beavan, 2006; Wallace, et al.,
2004; Zweck, et al., 2002]
[Hyndman, et al., 1997; Oleskevich, et al., 1999; Ruff
and Kanamori, 1983; Seno, 2005; Tichelaar and
Friday, November 23
Friday, November 30
Topic : ‘The Peru subduction zone’
Speakers : Aron
[Dorbath, et al., 1990; Gagnon, et al., 2005; Langer
and Spence, 1995; Pritchard, et al., 2007; Spence,
et al., 1999]
Friday, December 7
Topic : Debriefing of the seminar. Implications for current studies
Aki, K. (1984), Asperities, Barriers, Characteristic Earthquakes
and Strong Motion Prediction, Journal of Geophysical Research, 89,
Ammon, C. J., et al. (2005), Rupture process of the 2004 Sumatra-Andaman
earthquake, Science, 308, 1133-1139.
Briggs, R. W., et al. (2006), Deformation and slip along the Sunda
Megathrust in the great 2005 Nias-Simeulue earthquake, Science, 311,
Burgmann, R., et al. (2005), Interseismic coupling and asperity
distribution along the Kamchatka subduction zone, Journal of
Geophysical Research-Solid Earth, 110.
Chlieh, M., et al. (2005), Investigating lateral variations of
interseismic strain along the Sumatra subduction zone, Submitted
to J. Geophys. Res.
Chlieh, M., et al. (2007), Coseismic slip and afterslip of the
great M-w 9.15 Sumatra-Andaman earthquake of 2004, Bulletin
of the Seismological Society of America, 97, S152-S173.
Chlieh, M., et al. (2004), Crustal deformation and fault slip during
the seismic cycle in the North Chile subduction zone, from GPS
and InSAR observations, Geophys J Int., 158,
Cisternas, M., et al. (2005), Predecessors of the giant 1960 Chile
earthquake, Nature, 437, 404-407.
Cross, R. S., and J. T. Freymueller (2007), Plate coupling variation
and block translation in the Andreanof segment of the Aleutian
arc determined by subduction zone modeling using GPS data, Geophysical
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Dorbath, L., et al. (1990), Assessment of the size of large and
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Fournier, T. J., and J. T. Freymueller (2007), Transition from
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Freymueller, J. T., et al. (2000), Spatial variations in present-day
deformation, Kenai Peninsula, Alaska, and their implications, J.
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Gagnon, K., et al. (2005), Measuring the onset of locking in the
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Heaton, T. H. (1990), Evidence for and implications of self-healing
pulses of slip in earthquake rupture, Physics of the Earth
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Hsu, Y. J., et al. (2006), Frictional afterslip following the 2005
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Hyndman, R. D., et al. (1997), The seismogenic zone of subduction
thrust faults, The Island Arc, 6, 244-260.
Igarashi, T., et al. (2003), Repeating earthquakes and interplate
aseismic slip in the northeastern Japan subduction zone, Journal
of Geophysical Research-Solid Earth, 108.
Igarashi, T., et al. (2001), Spatial distribution of focal mechanisms
for interplate and intraplate earthquakes associated with the subducting
Pacific plate beneath the northeastern Japan arc: A triple-planed
deep seismic zone, Journal of Geophysical Research-Solid Earth, 106,
Kagan, Y. Y., and D. D. Jackson (1991), Seismic Gap Hypothesis: Ten
Years After, Journal of Geophysical Research, 96,
Kodaira, S., et al. (2006), A cause of rupture segmentation and
synchronization in the Nankai trough revealed by seismic imaging
and numerical simulation, Journal of Geophysical Research-Solid
Kodaira, S., et al. (2000), Subducted seamount imaged in the rupture
zone of the 1946 Nankaido earthquake, Science, 289,
Konca, A. O., et al. (2007), Rupture kinematics of the 2005 M-w
8.6 Nias-Simeulue earthquake from the joint inversion of seismic
and geodetic data, Bulletin of the Seismological Society of
America, 97, S307-S322.
Langer, C. J., and W. Spence (1995), The 1974 Peru Earthquake Series, Bulletin
of the Seismological Society of America, 85, 665-687.
Lay, T., et al. (2005), The great Sumatra-Andaman earthquake of
26 December 2004, Science, 308, 1127-1133.
Lay, T., et al. (1982), The Asperity Model and the Nature of Large
Subduction Zone Earthquakes, Earthquake Prediction Research, 1,
Llenos, A., and J. McGuire (2007), Influence of fore-arc structure
on the extent of great subduction zone earthquakes, Journal
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Mazzotti, S., et al. (1999), Full interseismic locking of the Nankaï and
Japan - West Kurile subduction zones: an analysis of uniform elastic
strain accumulation in japan constrained by permanent GPS, J.
Geophys. Res., 105, 13159-13177.
Meltzner, A. J., et al. (2006), Uplift and subsidence associated
with the great Aceh-Andaman earthquake of 2004, Journal of
Geophysical Research-Solid Earth, 111.
Mikumo, T., et al. (1998), Dynamic rupture of asperities and stress
change during a sequence of large interplate earthquakes in the
Mexican subduction zone, Bulletin of the Seismological Society
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Nakanishi, A., et al. (2004), Structural factors controlling the
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Natawidjaja, D., et al. (2004), Paleogeodetic records of seismic
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Natawidjaja, D. H., et al. (2006), Source parameters of the great
Sumatran megathrust earthquakes of 1797 and 1833 inferred from
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Newcomb, K., and W. McCann (1987), Seismic History and Seismotectonics
of the Sunda Arc, J. Geophys. Res., 92, 421-439.
Nishimura, T., et al. (2004), Temporal change of interplate coupling
in northeastern Japan during 1995-2002 estimated from continuous
GPS observations., Geophysical Journal International, 157,
Oleskevich, D. A., et al. (1999), The updip and downdip limits
to great subduction earthquakes: Thermal and structural models
of Cascadia, south Alaska, SW Japan, and Chile, Journal of
Geophysical Research-Solid Earth, 104, 14965-14991.
Pacheco, J. F., et al. (1993), Nature of Seismic Coupling Along
Simple Plate Boundaries of the Subduction Type, Journal of
Geophysical Research, 98, 14133-14160.
Park, S. C., and J. Mori (2007), Are asperity patterns persistent?
Implication from large earthquakes in Papua New Guinea, Journal
of Geophysical Research-Solid Earth, 112.
Pritchard, M. E., et al. (2007), Geodetic, teleseismic, and strong
motion constraints on slip from recent southern Peru subduction
zone earthquakes, Journal of Geophysical Research-Solid Earth, 112.
Ruff, L., and H. Kanamori (1983), Seismic Coupling and Uncoupling
at Subduction Zones, Tectonophysics, 99, 99-117.
Schwartz, S. Y. (1999), Noncharacteristic behavior and complex
recurrence of large subduction zone earthquakes, Journal of
Geophysical Research-Solid Earth, 104, 23111-23125.
Schwartz, S. Y., and L. J. Ruff (1987), Asperity Distribution and
Earthquake Occurrence in the Southern Kurile-Islands Arc, Physics
of the Earth and Planetary Interiors, 49, 54-77.
Seno, T. (2005), Variation of downdip limit of the seismogenic
zone near the Japanese islands: Implications for the serpentinization
mechanism of the forearc mantle wedge, Earth and Planetary
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Shimazaki, K., and T. Nakata (1980), Time-predictable recurrence
model for large earthquakes, Geophys. Res. Lett., 7,
Sieh, K., et al. (1999), Crustal deformation at the Sumatran subduction
zone revealed by coral rings, Geophysical Research Letters, 26,
Simoes, M., et al. (2004), The Sumatra subduction zone: A case
for a locked fault zone extending into the mantle, Journal
of Geophysical Research-Solid Earth, 109.
Song, T.-R. A., and M. Simons (2003), Large trench-parallel gravity
variations predict seismogenic behavior in subduction zones., Science, 301,
Spence, W., et al. (1999), Seismic subduction of the Nazca Ridge
as shown by the 1996-97 Peru earthquakes, Pure and Applied
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Suwa, Y., et al. (2006), Interplate coupling beneath NE Japan inferred
from three-dimensional displacement field, Journal of Geophysical
Research-Solid Earth, 111.
Sykes, L. R., and W. Menke (2006), Repeat times of large earthquakes:
Implications for earthquake mechanics and long-term prediction, Bulletin
of the Seismological Society of America, 96, 1569-1596.
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coupled subduction zones, J.Geophys.Res., 101,
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and the time-predictable model, J. Geophys. Res., 89,
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Tichelaar, B. W., and L. J. Ruff (1993), Depth of seismic coupling
along subduction zones, Journal of Geophysical Research, 98,
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the central Hikurangi subduction interface beneath the Manawatu
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Wallace, L. M., et al. (2004), Subduction zone coupling and tectonic
block rotations in the North Island, New Zealand, Journal of
Geophysical Research-Solid Earth, 109.
Wells, R. E., et al. (2003), Basin-centered asperities in great
subduction zone earthquakes: A link between slip, subsidence, and
subduction erosion?, Journal of Geophysical Research-Solid
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aftershocks associated with two large earthquakes in 1996 in Hyugia-nada,
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Zweck, C., et al. (2002), Three-dimensional elastic dislocation
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