WITHDRAWN Decade-to-Century Scale Vertical Earthquake-Cycle Deformation at Subduction Zones: Implications for Cascadia and Nankai
Description:
WITHDRAWN Despite significant progresses in studying subduction earthquake cycles, their vertical deformation is still not well understood.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. Subjective to 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 extent D to elastic upper plate thickness Hc (D/Hc)), our modeled viscoelastic deformation shows 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 the two parameter spaces, we further investigate three vertical characteristics, i.e., the pivot line near the coast (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 they all can be time-dependent, influenced by D/Hc and T/tM. CPL location and UZ width are mainly controlled by D/Hc and T/tM, respectively. The presence of SSZ is found prevalent during the interseismic phase due to viscous mantle flow driven by ongoing megathrust locking, consistent with observations in Cascadia and Nankai. The maximum uplifting rate of UZ and maximum subsiding rate of SSZ are likely controlled by the plate convergence rate inferred from the observations in Cascadia and Nankai. These findings suggest that vertical crustal deformation bears fruitful information about subduction-zone dynamics and are potentially used for inversions after careful forward validations, deserving properly-designed monitoring.
Session: Seismic Cycle-Driven Sea-Level Change Over Decades to Centuries: Observations and Projections [Poster Session]
Type: Poster
Date: 5/3/2024
Presentation Time: 08:00 AM (local time)
Presenting Author: Shaoyang
Student Presenter: No
Invited Presentation:
Authors
Shaoyang Li Presenting Author Corresponding Author shaoyangli@mail.iggcas.ac.cn Chinese Academy of Sciences |
Ling Chen lchen@mail.iggcas.ac.cn Chinese Academy of Sciences |
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WITHDRAWN Decade-to-Century Scale Vertical Earthquake-Cycle Deformation at Subduction Zones: Implications for Cascadia and Nankai
Category
Seismic Cycle-Driven Sea-Level Change Over Decades to Centuries: Observations and Projections