Combined GPS and InSAR Models of Postseismic Deformation from the Northridge Earthquake

Donnellan, Andrea; Parker, Jay; Peltzer, G.

doi:10.1007/s00024-002-8734-7

Cited by 29 publications

(11 citation statements)

References 20 publications

(20 reference statements)

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“…An obvious variation in the slip vectors between coseismic and postseismic motion has been identified, which may imply a significant rotation of the axis of greatest principal stress. As also found in the 1994 Northridge, California earthquake (Donnellan et al, 2002), rapid afterslip may commonly happen after an large earthquake, especially in thrust events. ) and beach balls show the mechanisms of major aftershocks determined by Irmak et al (2012).…”

Section: Discussionmentioning

confidence: 55%

Patterns and mechanisms of coseismic and postseismic slips of the 2011 M W 7.1 Van (Turkey) earthquake revealed by multi-platform synthetic aperture radar interferometry

Feng

Hoey

et al. 2014

Tectonophysics

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In this paper, we present several COSMO-SkyMED (CSK), Envisat ASAR and RADARSAT-2 interferograms spanning different time intervals, showing that significant postseismic signals can be observed in the first three days after the mainshock. Using observations that combine coseismic and postseismic signals is shown to significantly underestimate coseismic slip. We hence employed the CSK pair with the minimum postseismic signals to generate one conventional interferogram and one along-track interferogram for further coseismic modelling. Our best-fit coseismic slip model suggests that: (1) this event is associated with a buried NNW dipping fault with a preferable dip angle of 49º and a maximum slip of 6.5 m at a depth of 12 km; and (2) two unequal asperities can be observed, consistent with previous seismic solutions. Significant oblique aseismic slip with predominant left-lateral slip components above the coseismic rupture zone within the first 3 days after the mainshock is also revealed by a postseismic CSK interferogram, indicating that the greatest principal stress axis might have rotated due to a significant stress 1 drop during the coseismic rupture.

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Section: Discussionmentioning

confidence: 55%

Patterns and mechanisms of coseismic and postseismic slips of the 2011 M W 7.1 Van (Turkey) earthquake revealed by multi-platform synthetic aperture radar interferometry

Feng

Hoey

et al. 2014

Tectonophysics

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“…For a three-dimensional interactive version of the modeled fault geometry, refer to the interactive PDF file at http://www.appstate.edu/$marshallst/pubs/LA3D.pdf. afterslip and relaxation) in southern California are limited to only several years after a major earthquake [e.g., Donnellan et al, 2002;Fialko, 2004b]. Within the Los Angeles basin the last major earthquake was in 1994 (Northridge), therefore, postseismic transients are likely negligible.…”

Section: Conventional Interseismic Dislocation Modelsmentioning

confidence: 99%

Interseismic deformation associated with three‐dimensional faults in the greater Los Angeles region, California

Marshall¹,

Cooke²,

Owen³

2009

J. Geophys. Res.

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[1] Existing interseismic models are not well-suited to simulate deformation within the network of finite, intersecting, nonplanar faults observed in the greater Los Angeles region. Instead of applying fault slip rates to a model a priori, we allow three-dimensional fault surfaces to interact and accumulate mechanically viable slip distributions and then use the deep nonseismogenic portion of slip to calculate interseismic deformation. We apply this approach to the Los Angeles region and find that the geologic timescale model results match well geologic slip rate data and the interseismic timescale model results match well the heterogeneous GPS velocity pattern in the Los Angeles region. Model results suggest that localized geodetic convergence in the San Gabriel basin can be achieved with slip on multiple active fault surfaces in the Los Angeles region including relatively fast slip on the Sierra Madre fault and slow slip on the Puente Hills thrusts, in agreement with geologic data. The ability of the three-dimensional model to reproduce well both geologic slip rates and interseismic geodetic velocity patterns suggests that current day contraction rates in the greater Los Angeles region are compatible with long-term geologic deformation rates and disputes suggestions of significant temporal variations in fault slip rates inferred from existing investigations.

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“…Postseismic transient deformation has been measured on numerous active faults especially since the development of the Global Positioning System and the interferometric synthetic aperture radar techniques in the 1990s [ Chlieh et al ., ; Donnellan et al ., ; Ergintav et al ., ; Hsu et al ., ; Yu et al ., ]. In these studies, a fast strain rate, localized mostly in the fault zone, is observed immediately after the earthquake and progressively decreases with time.…”

Section: Introductionmentioning

confidence: 99%

Postseismic pressure solution creep: Evidence and time‐dependent change from dynamic indenting experiments

2014

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Active faults in the Earth's upper crust can slide either steadily by aseismic creep or abruptly causing earthquakes. Seismic and aseismic processes are closely related: earthquakes are often followed by transient afterslip creep. Postseismic displacement rates progressively decrease with time over a period of years or decades. So seismic fracturing activates the creep rate, and various healing processes progressively reduce it. This article presents pressure solution indenter experiments on halite, calcite, and plaster that show how fracturing and comminution processes induced by dynamic stress loading (applied by dropping steel balls) drastically accelerate the displacement rates accommodated by pressure solution creep by decreasing the dissolution contact area and the diffusive mass transfer distance along this contact. However, as fractures progressively heal and dissolution contacts flatten, these effects disappear, and the displacement rates slow down. The time-dependent change in indenter displacement after dynamic stress loading has been measured and is best fitted by power laws with exponents that change with time from 0.3 to 1 when healing is achieved. Natural postseismic (afterslip) displacement/time relationships have been analyzed and also show a power law change with a power law exponent in the range of 0.25-0.4. It is proposed that the variation in power law exponent with time is related to the change in morphology of the dissolution contact that is fractured or comminuted during the dynamic event and is then progressively healed and smoothed. In natural faults, monitoring the power law parameters could give access to the characteristic healing time in the fault.

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Combined GPS and InSAR Models of Postseismic Deformation from the Northridge Earthquake

Cited by 29 publications

References 20 publications

Patterns and mechanisms of coseismic and postseismic slips of the 2011 M W 7.1 Van (Turkey) earthquake revealed by multi-platform synthetic aperture radar interferometry

Patterns and mechanisms of coseismic and postseismic slips of the 2011 M W 7.1 Van (Turkey) earthquake revealed by multi-platform synthetic aperture radar interferometry

Interseismic deformation associated with three‐dimensional faults in the greater Los Angeles region, California

Postseismic pressure solution creep: Evidence and time‐dependent change from dynamic indenting experiments

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