How Long Can the Postseismic and Interseismic Phases of Great Subduction Earthquake Sustain? Toward an Integrated Earthquake‐Cycle Perspective

Li, Shaoyang; Chen, Ling

doi:10.1029/2023gl103976

Cited by 5 publications

(1 citation statement)

References 113 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We therefore chose to model internal deformation by a sliver and estimate the variability in the models to assess the seismic potential and its uncertainties (cf., next section). A viscoelastic model that accounts for viscoelastic deformation, including the relaxation following the 2001 Arequipa and the 2007 Pisco earthquake, should ideally be performed to move toward a better mechanical interpretation of the deformation field in the central Andes that account for the whole seismic cycle (e.g., Li & Chen, 2023).…”

Section: Possible Effect Of Viscoelastic Rheology On the Interseismic...mentioning

confidence: 99%

Heterogeneous Locking and Earthquake Potential on the South Peru Megathrust From Dense GNSS Network

Lovery,

Chlieh,

Norabuena

et al. 2024

JGR Solid Earth

View full text Add to dashboard Cite

The Central Andes subduction has been the theater of numerous large earthquakes since the beginning of the 21st Century, notably the 2001 Mw = 8.4 Arequipa, 2007 Mw = 8.0 Pisco and 2014 Mw = 8.1 Iquique earthquakes. We present an analysis of 47 permanent and 26 survey global navigation satellite system (GNSS) measurements acquired in Central‐South Peru between 2007 and 2022 to better understand the frictional properties of the megathrust interface. Using a trajectory model that mimics the different phases of the cycle, we extract a coherent interseismic GNSS field at the scale of the Central Andes from Lima to Arica (12–18.5°S). Interseismic models on a 3D slab geometry indicate that the locking level is relatively high and concentrated between 20 and 40‐km depth. Locking distributions indicate a high spatial variability of the coupling along the trench, with the presence of many locked patches that spatially correlate with the seismotectonic segmentation. Our study confirms the presence of a creeping segment where the Nazca Ridge is subducting; we also observe a lighter apparent decrease of coupling related to the Nazca Fracture Zone (NFZ). However, since the Nazca Ridge appears to behave as a strong barrier, the NFZ is less efficient to arrest seismic rupture propagation. Considering various uncertainty factors, we discuss the implication of our coupling estimates with size and timing of large megathrust earthquakes considering both deterministic and probabilistic approaches. We estimate that the South Peru segment could have a Mw = 8.4–9.0 earthquake potential depending principally on the considered seismic catalog and the seismic/aseismic slip ratio.

show abstract

Section: Possible Effect Of Viscoelastic Rheology On the Interseismic...mentioning

confidence: 99%

Heterogeneous Locking and Earthquake Potential on the South Peru Megathrust From Dense GNSS Network

Lovery,

Chlieh,

Norabuena

et al. 2024

JGR Solid Earth

View full text Add to dashboard Cite

show abstract

Weak, Vertically Stronger Main Himalayan Thrust in the India‐Asia Collision

Li,

Schulte‐Pelkum,

Barnhart

et al. 2024

Geophysical Research Letters

View full text Add to dashboard Cite

Megathrusts at convergent plate boundaries generate the largest and some of the most hazardous earthquakes on Earth. However, their physical properties, including those influencing fault slip accumulation and release and earthquake‐related surface displacements, are still poorly constrained at critical depths. Here, we combine seismic imaging and geodetic modeling to investigate the structure and mechanical behavior of the Main Himalayan Thrust fault (MHT) in the center of the 2015 Mw 7.8 Gorkha rupture in Nepal. Our results from two independent observations consistently suggest the presence of a channel associated with the MHT with high compliance (shear modulus as low as ∼4 GPa) and strain anisotropy (stiffer in the vertical orientation than in the horizontal), likely arising from a weak subducting layer with north‐dipping foliation. Such mechanical heterogeneity significantly influences the quantification of short‐term fault kinematics and associated earthquake potential, with implications on across‐scale dynamics of plate boundaries in Himalaya and elsewhere.

show abstract

Vertical Crustal Deformation Due To Viscoelastic Earthquake Cycles at Subduction Zones: Implications for Nankai and Cascadia

Li,

Chen

2024

JGR Solid Earth

View full text Add to dashboard Cite

Despite significant progress in studying subduction earthquake cycles, the vertical deformation is still not well understood. Here, we use a generic viscoelastic earthquake‐cycle model that has recently been validated by horizontal observations to explore the dynamics of vertical earthquake‐cycle deformation. Conditioned on two dimensionless parameters (i.e., the ratio of earthquake recurrence interval T to mantle Maxwell relaxation time tM (T/tM) and the ratio of downdip seismogenic depth D to elastic upper‐plate thickness Hc (D/Hc)), the modeled viscoelastic deformation exhibits significant spatiotemporal deviations from the simple time‐independent elastic solution. Caution thus should be exercised in interpreting fault kinematics with vertical observations if ignoring Earth's viscoelasticity. By systematically exploring these two parameters, we further investigate three metrics that characterize the predicted vertical deformation: the coastal pivot line (CPL), the uplift zone (UZ) landward above the downdip seismogenic extent, and the secondary subsidence zone (SSZ) in the back‐arc region. We find that these metrics can all be time‐dependent, subject to D/Hc and T/tM. The CPL location and the UZ width are mainly controlled by D/Hc and T/tM, respectively. The presence of the SSZ is prevalent during the interseismic phase due to viscous mantle flow driven by ongoing plate convergence. Contemporary vertical deformation in Nankai and Cascadia is largely consistent with the model predictions and features differences mainly related to contrasting D/Hc values in the two margins. These findings suggest that vertical crustal deformation bears fruitful information about subduction‐zone dynamics and is potentially useful for inversions of key subduction‐zone parameters, deserving properly designed monitoring.

show abstract

How Long Can the Postseismic and Interseismic Phases of Great Subduction Earthquake Sustain? Toward an Integrated Earthquake‐Cycle Perspective

Cited by 5 publications

References 113 publications

Heterogeneous Locking and Earthquake Potential on the South Peru Megathrust From Dense GNSS Network

Heterogeneous Locking and Earthquake Potential on the South Peru Megathrust From Dense GNSS Network

Weak, Vertically Stronger Main Himalayan Thrust in the India‐Asia Collision

Vertical Crustal Deformation Due To Viscoelastic Earthquake Cycles at Subduction Zones: Implications for Nankai and Cascadia

Contact Info

Product

Resources

About