A large slow slip event and the depth of the seismogenic zone in the south central Alaska subduction zone

ABSTRACT Strong-motion observations of recent interface earthquakes along the Chilean subduction zone are evaluated with two ground-motion models (GMM). One GMM was developed with Chilean data and the other with global data. The GMM developed with local Chilean data is found to have an overall better prediction performance than the GMM developed using a global data set. Using residual analysis with the Chilean GMM as reference model due to its better performance, clear indications of an increase of short-period radiation for deeper earthquakes in north and central Chile were found, which may be related to frictional features on the interface such as interseismic coupling, as found previously for other regions, such as Japan. Also, the Iquique earthquake, which featured a clear precursory slow-slip event, exhibits mostly negative between-event residuals at short periods for earthquakes before and after the mainshock, indicating predominantly weaker short-period radiation. However, this trend is not observed in the aftershock sequence of the Illapel earthquake, which did not feature a significant slow-slip event nor precursory seismicity in its rupture area. Finally, a poor predictive performance was found for the Chilean GMM in southern Chile, overpredicting most of the observations. Based on these results, it is proposed that future local GMMs should include corrections for depth, regional effects and include earthquakes from southern Chile, as new data are becoming available in this region.

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Time‐Dependent Behavior of a Near‐Trench Slow‐Slip Event at the Hikurangi Subduction Zone

Geochemistry Geophysics Geosystems ◽

10.1029/2019gc008229 ◽

2019 ◽

Vol 20 (8) ◽

pp. 4292-4304 ◽

Cited By ~ 2

Author(s):

R. Yohler ◽

N. Bartlow ◽

L. M. Wallace ◽

C. Williams

Keyword(s):

Subduction Zone ◽

Time Dependent ◽

Slow Slip ◽

Slow Slip Event ◽

Dependent Behavior ◽

Slip Event

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The 2006 slow slip event and nonvolcanic tremor in the Mexican subduction zone

Geophysical Research Letters ◽

10.1029/2010gl045424 ◽

2010 ◽

Vol 37 (24) ◽

pp. n/a-n/a ◽

Cited By ~ 67

Author(s):

Vladimir Kostoglodov ◽

Allen Husker ◽

Nikolai M. Shapiro ◽

Juan S. Payero ◽

Michel Campillo ◽

...

Keyword(s):

Subduction Zone ◽

Slow Slip ◽

Slow Slip Event ◽

Slip Event ◽

Mexican Subduction Zone

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Interplate coupling and a recent aseismic slow slip event in the Guerrero seismic gap of the Mexican subduction zone, as deduced from GPS data inversion using a Bayesian information criterion

Physics of The Earth and Planetary Interiors ◽

10.1016/j.pepi.2004.05.006 ◽

2004 ◽

Vol 146 (3-4) ◽

pp. 513-530 ◽

Cited By ~ 51

Author(s):

Shoichi Yoshioka ◽

Takeshi Mikumo ◽

Vladimir Kostoglodov ◽

Kristine M Larson ◽

Anthony R Lowry ◽

...

Keyword(s):

Subduction Zone ◽

Bayesian Information Criterion ◽

Information Criterion ◽

Gps Data ◽

Seismic Gap ◽

Slow Slip ◽

Slow Slip Event ◽

Data Inversion ◽

Interplate Coupling ◽

Slip Event

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Slow slip on the northern Hikurangi subduction interface, New Zealand

10.26686/wgtn.13819082 ◽

2021 ◽

Author(s):

A Douglas ◽

J Beavan ◽

L Wallace ◽

John Townend

Keyword(s):

New Zealand ◽

Surface Displacement ◽

Seismogenic Zone ◽

Gps Data ◽

Slow Slip ◽

Slow Slip Event ◽

Slip Event ◽

American Geophysical ◽

Continuous Gps ◽

American Geophysical Union

In October 2002, a surface displacement episode of 20-30 mm magnitude was observed over a ∼10 day period on two continuous Global Positioning System (GPS) instruments near Gisborne, North Island, New Zealand. We interpret this to result from slow slip on the northern Hikurangi subduction interface. Using ten years of regional campaign GPS (1995-2004) and recent continuous GPS data, we estimate the recurrence interval for similar events to be 2-3 yrs. In November 2004, a similar slow slip event occurred within this recurrence period. The 2002 event can be modeled by ∼18 cm of slow slip near the down-dip end of the seismogenic zone on the subduction interface offshore of Gisborne. The campaign GPS data show that the 2002 slow slip event had little effect on regional strain patterns. Copyright 2005 by the American Geophysical Union.

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Adjoint slip inversion under a constrained optimization framework: revisiting the 2006 guerrero slow slip event

Geophysical Journal International ◽

10.1093/gji/ggab165 ◽

2021 ◽

Author(s):

J Tago ◽

V M Cruz-Atienza ◽

C Villafuerte ◽

T Nishimura ◽

V Kostoglodov ◽

...

Keyword(s):

Model Space ◽

Seismogenic Zone ◽

Inversion Method ◽

Seismic Gap ◽

Slow Slip ◽

Inversion Algorithm ◽

Plate Interface ◽

Tectonic Plates ◽

Slow Slip Event ◽

Slip Event

Summary To shed light on the prevalently slow, aseismic slip interaction between tectonic plates, we developed a new static slip inversion strategy, the ELADIN (ELastostatic ADjoint INversion) method, that uses the adjoint elastostatic equations to compute the gradient of the cost function. ELADIN is a 2-step inversion algorithm to efficiently handle plausible slip constraints. First it finds the slip that best explains the data without any constraint, and then refines the solution by imposing the constraints through a Gradient Projection Method. To obtain a selfsimilar, physically-consistent slip distribution that accounts for sparsity and uncertainty in the data, ELADIN reduces the model space by using a von Karman regularization function that controls the wavenumber content of the solution, and weights the observations according to their covariance using the data precision matrix. Since crustal deformation is the result of different concomitant interactions at the plate interface, ELADIN simultaneously determines the regions of the interface subject to both stressing (i.e., coupling) and relaxing slip regimes. For estimating the resolution, we introduce a mobile checkerboard analysis that allows to determine lower-bound fault resolution zones for an expected slip-patch size and a given stations array. We systematically test ELADIN with synthetic inversions along the whole Mexican subduction zone and use it to invert the 2006 Guerrero Slow Slip Event (SSE), which is one of the most studied SSEs in Mexico. Since only 12 GPS stations recorded the event, careful regularization is thus required to achieve reliable solutions. We compared our preferred slip solution with two previously published models and found that our solution retains their most reliable features. In addition, although all three SSE models predict an upward slip penetration invading the seismogenic zone of the Guerrero seismic gap, our resolution analysis indicates that this penetration might not be a reliable feature of the 2006 SSE.

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