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Structural and Seismologic Characterization of the Newport-Inglewood Fault of Los Angeles, California, and the Seattle Fault Zone and Basin Edge of Seattle, Washington: Implications for Urban Seismic Hazard Assessment
Structural and Seismologic Characterization of the Newport-Inglewood Fault of Los Angeles, California, and the Seattle Fault Zone and Basin Edge of Seattle, Washington: Implications for Urban Seismic Hazard Assessment
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20260202103605
- ISBN
- 9798280718302
- DDC
- 551
- 서명/저자
- Structural and Seismologic Characterization of the Newport-Inglewood Fault of Los Angeles, California, and the Seattle Fault Zone and Basin Edge of Seattle, Washington: Implications for Urban Seismic Hazard Assessment
- 발행사항
- [Sl] : Harvard University, 2025
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2025
- 형태사항
- 193 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 86-12, Section: B.
- 주기사항
- Advisor: Shaw, John.
- 학위논문주기
- Thesis (Ph.D.)--Harvard University, 2025.
- 초록/해제
- 요약Active fault systems located in densely-populated urban settings, especially those set within sedimentary basins that are known to amplify earthquake ground motions, pose some of the greatest seismic hazards in the world. Understanding these faults' 3D structure and subsurface geometries is a critical element of understanding these hazards, including the expected patterns of surface faulting and levels of strong seismic shaking during future earthquakes. In this work, we characterize two active, complex, and hazardous fault systems located in densely populated U.S. cities. We define the 3D geometry of the Newport-Inglewood fault in the Los Angeles basin, California, using an unprecedented dataset of surface trace maps, oil wells, geophysical surveys, and seismicity. In contrast to simplified representations of the fault in current hazard maps and fault models, we show that the system contains 300 distinct fault segments that define a broad (up to 8 km wide) zone of surface faulting that poses significant fault displacement hazards. In addition, we show that the complex network of fault segments contains several potential earthquake gates that may accommodate or limit ruptures, thus informing our assessment of future earthquake magnitudes. Using an array of densely-spaced nodal seismometers we deployed as part of this study, we help define the location of the Seattle fault zone and basin edge by resolving seismological effects with high spatial resolution. We pinpoint where the SFZ scatters and diffracts earthquake waves, as well as where seismic wave velocities measurably change in the SFZ. We perform P wave polarization analysis and ambient noise cross-correlation processing to constrain shallow shear and surface wave velocities, which are critical values for seismic hazard and geotechnical assessments. These results help us understand the future basin-edge effects expected to contribute to strong seismic shaking in future earthquakes in Seattle.The Newport-Inglewood fault (NIF)The Newport-Inglewood fault (NIF) is a complex, active right-lateral strike-slip fault system that extends over 60 km in length across metropolitan Los Angeles, California. The NIF forms the western boundary of the central Los Angeles sedimentary basin, and in current hazard maps has a complex pattern of disconnected active surface fault traces that are distributed over a broad area (USGS QFaults). The southern portion of the NIF generated the 1933 M 6.4 Long Beach earthquake, the deadliest seismic event in southern California history. The California Division of Mines and Geology (1988) and other sources describe a future earthquake on the NIF as one of the greatest hazards to life and property in the United States. Along the NIF are ten large anticlines, which include some of the largest and most productive oil fields in southern California. These oil fields have been intensively explored by petroleum operations for over a century, which now provides one of the densest and highest-resolution subsurface datasets for any active fault system in the world. Many other geologic and seismologic datasets help define the NIF, including: mapped surface fault traces, 31 2D seismic reflection profiles that cross the fault system, comprehensive regional seismicity catalogs that collectively include over 1 million earthquakes, and petroleum industry contour maps of subsurface rock units deformed by the fault system. These datasets span a remarkable depth range, from the Earth's surface down to a depth of ~20 km. We integrate and analyze all of these datasets in a computer-aided design (CAD) modeling environment to build a comprehensive 3D representation of the fault system.We find that the NIF is comprised of 300 distinct, individual faults. These faults fall generally into two classes: large, NW-trending strike-slip faults, many of which are over 10 km in length, and smaller linking faults, which have diverse orientations and physically connect the strike-slip faults. The complete NIF system extends over a broad zone of surface faulting, reaching over ~8 km in some areas. This fault zone width is largely maintained at depth. Faults do not coalesce into a narrow master system-rather, large throughgoing strike-slip faults extend to the base of the seismogenic crust (~15 km depth), interpenetrating each other, and forming a ~5-8 km wide zone of throughgoing strike-slip faults at the base of the seismogenic crust. The 3D fault geometry of the NIF resolved in our model has critical implications for seismic hazard in Los Angeles. Ground surface rupture is defined by the extent of potentially active faults that may rupture the surface in an earthquake on a given fault system. Potential rupture magnitude is dictated by the total available surface area of viable fault rupture patches, and by the connectivity of distinct fault planes, which can enable ruptures to pass across multiple fault segments. Surface rupture on complex, multi-fault systems pose significant fault displacement. (Abstract shortened by ProQuest).
- 일반주제명
- Geology
- 일반주제명
- Geophysics
- 기타저자
- Harvard University Earth and Planetary Sciences
- 기본자료저록
- Dissertations Abstracts International. 86-12B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■006m o d
■007cr#unu||||||||
■020 ▼a9798280718302
■035 ▼a(MiAaPQ)AAI32042702
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a551
■1001 ▼aToghramadjian, Natasha Elyse.▼0(orcid)0000-0003-4436-6058
■24510▼aStructural and Seismologic Characterization of the Newport-Inglewood Fault of Los Angeles, California, and the Seattle Fault Zone and Basin Edge of Seattle, Washington: Implications for Urban Seismic Hazard Assessment
■260 ▼a[Sl]▼bHarvard University▼c2025
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2025
■300 ▼a193 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 86-12, Section: B.
■500 ▼aAdvisor: Shaw, John.
■5021 ▼aThesis (Ph.D.)--Harvard University, 2025.
■520 ▼aActive fault systems located in densely-populated urban settings, especially those set within sedimentary basins that are known to amplify earthquake ground motions, pose some of the greatest seismic hazards in the world. Understanding these faults' 3D structure and subsurface geometries is a critical element of understanding these hazards, including the expected patterns of surface faulting and levels of strong seismic shaking during future earthquakes. In this work, we characterize two active, complex, and hazardous fault systems located in densely populated U.S. cities. We define the 3D geometry of the Newport-Inglewood fault in the Los Angeles basin, California, using an unprecedented dataset of surface trace maps, oil wells, geophysical surveys, and seismicity. In contrast to simplified representations of the fault in current hazard maps and fault models, we show that the system contains 300 distinct fault segments that define a broad (up to 8 km wide) zone of surface faulting that poses significant fault displacement hazards. In addition, we show that the complex network of fault segments contains several potential earthquake gates that may accommodate or limit ruptures, thus informing our assessment of future earthquake magnitudes. Using an array of densely-spaced nodal seismometers we deployed as part of this study, we help define the location of the Seattle fault zone and basin edge by resolving seismological effects with high spatial resolution. We pinpoint where the SFZ scatters and diffracts earthquake waves, as well as where seismic wave velocities measurably change in the SFZ. We perform P wave polarization analysis and ambient noise cross-correlation processing to constrain shallow shear and surface wave velocities, which are critical values for seismic hazard and geotechnical assessments. These results help us understand the future basin-edge effects expected to contribute to strong seismic shaking in future earthquakes in Seattle.The Newport-Inglewood fault (NIF)The Newport-Inglewood fault (NIF) is a complex, active right-lateral strike-slip fault system that extends over 60 km in length across metropolitan Los Angeles, California. The NIF forms the western boundary of the central Los Angeles sedimentary basin, and in current hazard maps has a complex pattern of disconnected active surface fault traces that are distributed over a broad area (USGS QFaults). The southern portion of the NIF generated the 1933 M 6.4 Long Beach earthquake, the deadliest seismic event in southern California history. The California Division of Mines and Geology (1988) and other sources describe a future earthquake on the NIF as one of the greatest hazards to life and property in the United States. Along the NIF are ten large anticlines, which include some of the largest and most productive oil fields in southern California. These oil fields have been intensively explored by petroleum operations for over a century, which now provides one of the densest and highest-resolution subsurface datasets for any active fault system in the world. Many other geologic and seismologic datasets help define the NIF, including: mapped surface fault traces, 31 2D seismic reflection profiles that cross the fault system, comprehensive regional seismicity catalogs that collectively include over 1 million earthquakes, and petroleum industry contour maps of subsurface rock units deformed by the fault system. These datasets span a remarkable depth range, from the Earth's surface down to a depth of ~20 km. We integrate and analyze all of these datasets in a computer-aided design (CAD) modeling environment to build a comprehensive 3D representation of the fault system.We find that the NIF is comprised of 300 distinct, individual faults. These faults fall generally into two classes: large, NW-trending strike-slip faults, many of which are over 10 km in length, and smaller linking faults, which have diverse orientations and physically connect the strike-slip faults. The complete NIF system extends over a broad zone of surface faulting, reaching over ~8 km in some areas. This fault zone width is largely maintained at depth. Faults do not coalesce into a narrow master system-rather, large throughgoing strike-slip faults extend to the base of the seismogenic crust (~15 km depth), interpenetrating each other, and forming a ~5-8 km wide zone of throughgoing strike-slip faults at the base of the seismogenic crust. The 3D fault geometry of the NIF resolved in our model has critical implications for seismic hazard in Los Angeles. Ground surface rupture is defined by the extent of potentially active faults that may rupture the surface in an earthquake on a given fault system. Potential rupture magnitude is dictated by the total available surface area of viable fault rupture patches, and by the connectivity of distinct fault planes, which can enable ruptures to pass across multiple fault segments. Surface rupture on complex, multi-fault systems pose significant fault displacement. (Abstract shortened by ProQuest).
■590 ▼aSchool code: 0084.
■650 4▼aGeology
■650 4▼aGeophysics
■653 ▼aActive fault systems
■653 ▼aSedimentary basins
■653 ▼aGeophysical surveys
■690 ▼a0372
■690 ▼a0373
■690 ▼a0467
■71020▼aHarvard University▼bEarth and Planetary Sciences.
■7730 ▼tDissertations Abstracts International▼g86-12B.
■790 ▼a0084
■791 ▼aPh.D.
■792 ▼a2025
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17357829▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
