• Login
    View Item 
    •   Home
    • Theses and Dissertations
    • PhD Dissertations
    • View Item
    •   Home
    • Theses and Dissertations
    • PhD Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of KAUSTCommunitiesIssue DateSubmit DateThis CollectionIssue DateSubmit Date

    My Account

    Login

    Quick Links

    Open Access PolicyORCID LibguideTheses and Dissertations LibguideSubmit an Item

    Statistics

    Display statistics

    Earthquake ground-motion in presence of source and medium heterogeneities

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    JagdishVyasThesis.pdf
    Size:
    8.688Mb
    Format:
    PDF
    Description:
    JagdishVyas Dissertation
    Download
    Type
    Dissertation
    Authors
    Vyas, Jagdish Chandra cc
    Advisors
    Mai, Paul Martin cc
    Committee members
    Jonsson, Sigurjon cc
    Hadwiger, Markus cc
    Cotton, Fabrice
    Program
    Earth Science and Engineering
    KAUST Department
    Physical Science and Engineering (PSE) Division
    Date
    2017
    Embargo End Date
    2017-05-14
    Permanent link to this record
    http://hdl.handle.net/10754/623617
    
    Metadata
    Show full item record
    Access Restrictions
    At the time of archiving, the student author of this dissertation opted to temporarily restrict access to it. The full text of this dissertation became available to the public after the expiration of the embargo on 2017-05-14.
    Abstract
    This dissertation work investigates the effects of earthquake rupture complexity and heterogeneities in Earth structure on near-field ground-motions. More specifically, we address two key issues in seismology: (1) near-field ground-shaking variability as function of distance and azimuth for unilateral directive ruptures, and (2) impact of rupture complexity and seismic scattering on Mach wave coherence associated with supershear rupture propagation. We examine earthquake ground-motion variability associated with unilateral ruptures based on ground-motion simulations of the MW 7.3 1992 Landers earthquake, eight simplified source models, and a MW 7.8 rupture simulation (ShakeOut) for the San Andreas fault. Our numerical modeling reveals that the ground-shaking variability in near-fault distances (< 20 km) is larger than that given by empirical ground motion prediction equations. In addition, the variability decreases with increasing distance from the source, exhibiting a power-law decay. The high near-field variability can be explained by strong directivity effects whose influence weaken as we move away from the fault. At the same time, the slope of the power-law decay is found to be dominantly controlled by slip heterogeneity. Furthermore, the ground-shaking variability is high in the rupture propagation direction whereas low in the directions perpendicular to it. However, the variability expressed as a function of azimuth is not only sensitive to slip heterogeneity, but also to rupture velocity. To study Mach wave coherence for supershear ruptures, we consider heterogeneities in rupture parameters (variations in slip, rise time and rupture speed) and 3D scattering media having small-scale random heterogeneities. The Mach wave coherence is reduced at near-fault distances (< 10 km) by the source heterogeneities. At the larger distances from the source, medium scattering plays the dominant role in reducing the Mach wave coherence. Combined effect of the source and medium heterogeneities on the supershear ruptures produce peak ground accelerations consistent with the estimates from empirical ground motion prediction equations. Therefore, we suggest that supershear ruptures may be more common in nature than detected.
    Citation
    Vyas, J. C. (2017). Earthquake ground-motion in presence of source and medium heterogeneities. KAUST Research Repository. https://doi.org/10.25781/KAUST-IMX76
    DOI
    10.25781/KAUST-IMX76
    ae974a485f413a2113503eed53cd6c53
    10.25781/KAUST-IMX76
    Scopus Count
    Collections
    PhD Dissertations; Physical Science and Engineering (PSE) Division; Earth Science and Engineering Program

    entitlement

     
    DSpace software copyright © 2002-2022  DuraSpace
    Quick Guide | Contact Us | KAUST University Library
    Open Repository is a service hosted by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items. For anonymous users the allowed maximum amount is 50 search results.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.