Thrust Fault Slip Rates Deduced from Coupled Geomorphic and Tectonic Models of Active Faults and Folds in the San Francisco Bay Area PDF Download

Author: George E. Hilley
Publisher:
ISBN:
Category : Folds (Geology)
Languages : en
Pages : 106

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Author: Sebastiano D'Amico
Publisher: BoD – Books on Demand
ISBN: 9533079916
Category : Science
Languages : en
Pages : 420

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Book Description
This book is devoted to different aspects of earthquake research. Depending on their magnitude and the placement of the hypocenter, earthquakes have the potential to be very destructive. Given that they can cause significant losses and deaths, it is really important to understand the process and the physics of this phenomenon. This book does not focus on a unique problem in earthquake processes, but spans studies on historical earthquakes and seismology in different tectonic environments, to more applied studies on earthquake geology.

Author: Ken McClay
Publisher: AAPG
ISBN: 0891813764
Category : Science
Languages : en
Pages : 404

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Author: Douglas W. Burbank
Publisher: John Wiley & Sons
ISBN: 1444345044
Category : Science
Languages : en
Pages : 494

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Book Description
Tectonic geomorphology is the study of the interplay between tectonic and surface processes that shape the landscape in regions of active deformation and at time scales ranging from days to millions of years. Over the past decade, recent advances in the quantification of both rates and the physical basis of tectonic and surface processes have underpinned an explosion of new research in the field of tectonic geomorphology. Modern tectonic geomorphology is an exceptionally integrative field that utilizes techniques and data derived from studies of geomorphology, seismology, geochronology, structure, geodesy, stratigraphy, meteorology and Quaternary science. While integrating new insights and highlighting controversies from the ten years of research since the 1st edition, this 2nd edition of Tectonic Geomorphology reviews the fundamentals of the subject, including the nature of faulting and folding, the creation and use of geomorphic markers for tracing deformation, chronological techniques that are used to date events and quantify rates, geodetic techniques for defining recent deformation, and paleoseismologic approaches to calibrate past deformation. Overall, this book focuses on the current understanding of the dynamic interplay between surface processes and active tectonics. As it ranges from the timescales of individual earthquakes to the growth and decay of mountain belts, this book provides a timely synthesis of modern research for upper-level undergraduate and graduate earth science students and for practicing geologists. Additional resources for this book can be found at: www.wiley.com/go/burbank/geomorphology.

Author: Justin W. Herbert
Publisher:
ISBN:
Category :
Languages : en
Pages : 171

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This dissertation aims to understand fault system deformation using numerical models and analog experiments. In southern California, the southern Big Bend of the San Andreas fault (SAF) is a zone of transpression that accommodates deformation associated with the Pacific-North American plate boundary. Using three-dimensional boundary element method (BEM) models, I test the sensitivity of fault slip rates to a range of tectonic boundary conditions constrained by Global Positioning System (GPS) studies of the region (45-50 mm/yr and 320°- 325°). I have modified fault configurations derived from the Southern California Earthquake Center Community Fault Model of the San Gorgonio knot and the eastern California shear zone (ECSZ) to better represent the disconnected nature of active faults in southern California. The models with revised fault geometry produce slip rates that better match geologic strike-slip rates, thus validating the revisions. More northerly plate velocity (325°) produces greater transpression along the SAF system associated with greater uplift of the San Bernardino Mountains, greater reverse-slip rates along range bounding reverse thrust faults, lower strike-slip rates along the San Andreas and San Jacinto faults, and greater strike-slip rates along the eastern California shear zone (ECSZ) and Garlock fault. These results suggest that the degree of regional transpression controls the partitioning of deformation between uplift and slip along both the SAF system and the ECSZ. Along the San Bernardino strand of the SAF and across the ECSZ, geologic slip rates differ from those inverted from geodetic measurements, which may partly be due to inaccurate fault connectivity within geodetic models. I compare results from fault networks that follow mapped geologic traces and resemble those used in block model inversions, which connect the San Jacinto fault to the SAF near Cajon Pass and connect distinct faults within the ECSZ. The connection of the SAF with the San Jacinto fault decreases strike-slip rates along the SAF by up to 10% and increases strike-slip rates along the San Jacinto fault by up to 16%; however, slip rate changes are still within the large geologic ranges along the SAF. The insensitivity of modeled interseismic surface velocities near Cajon Pass to fault connection suggests that inverse models may utilize both an incorrect fault geometry and slip rate and still provide an excellent fit to interseismic geodetic data. Similarly, connection of faults within the ECSZ produces 36% greater cumulative strike-slip rates but less than 17% increase in interseismic velocity. Within the models that follow the mapped traces, off-fault deformation accounts for 40% ± 23% of the total strain across the ECSZ. This suggests that a significant portion of the discrepancy between the geologic and geodetically modeled slip rates in the ECSZ could be due to the geodetic inversion model assumption of zero permanent off-fault deformation. When using overconnected models to invert GPS for slip rates, the reduced off-fault deformation within the models can lead to overprediction of slip rates. Analog models of sandbox experiments performed at the Universite de Cergy-Pontoise (UCP) shed light on the amount of work required to create faults (Wgrow) in coarse sand. Casagrande shear experiments calculate a Wgrow that is consistent with that calculated in the sandbox and both values scale properly to crustal calculations. Calculations of Wgrow are higher for thicker sand pack layer experiments. Utilizing different materials within the compressional sandbox (GA39 sand and glass beads) shows the control of material properties on Wgrow as well. Numerical simulations of the UCP sandbox experiments test whether fault growth occurs via work minimization. To the first order, faults observed in sandbox experiments match the model predicted faults that minimize work in two-dimensional BEM simulations. The BEM models and work minimization shed light on fault growth path and timing.

Author: National Research Council
Publisher: National Academies Press
ISBN: 0309065623
Category : Science
Languages : en
Pages : 431

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Book Description
The destructive force of earthquakes has stimulated human inquiry since ancient times, yet the scientific study of earthquakes is a surprisingly recent endeavor. Instrumental recordings of earthquakes were not made until the second half of the 19th century, and the primary mechanism for generating seismic waves was not identified until the beginning of the 20th century. From this recent start, a range of laboratory, field, and theoretical investigations have developed into a vigorous new discipline: the science of earthquakes. As a basic science, it provides a comprehensive understanding of earthquake behavior and related phenomena in the Earth and other terrestrial planets. As an applied science, it provides a knowledge base of great practical value for a global society whose infrastructure is built on the Earth's active crust. This book describes the growth and origins of earthquake science and identifies research and data collection efforts that will strengthen the scientific and social contributions of this exciting new discipline.

Author: Doris Sloan
Publisher: Univ of California Press
ISBN: 0520241266
Category : Nature
Languages : en
Pages : 353

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Book Description
"You can't really know the place where you live until you know the shapes and origins of the land around you. To feel truly at home in the Bay Area, read Doris Sloan's intriguing stories of this region's spectacular, quirky landscapes."—Hal Gilliam, author of Weather of the San Francisco Bay Region "This is a fascinating look at some of the world's most complex and engaging geology. I highly recommend this book to anyone interested in an understanding of the beautiful landscape and dynamic geology of the Bay Area."—Mel Erskine, geological consultant "This accessible summary of San Francisco Bay Area geology is particularly timely. We are living in an age where we must deal with our impact on our environment and the impact of the environment on us. Earthquake hazards, and to a lesser extent landslide hazards, are well known, but the public also needs to be aware of other important engineering and environmental impacts and geologic resources. This book will allow Bay Area residents to make more intelligent decisions about the geological issues affecting their lives."—John Wakabayashi, geological consultant

Author: Keith I. Kelson
Publisher:
ISBN:
Category : Earthquake hazard analysis
Languages : en
Pages : 30

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Author: William R. Lund
Publisher: Utah Geological Survey
ISBN: 1557917272
Category : Science
Languages : en
Pages : 114

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Book Description
This report presents the results of the Utah Quaternary Fault Parameters Working Group (hereafter referred to as the Working Group) review and evaluation of Utah’s Quaternary fault paleoseismic-trenching data. The purpose of the review was to (1) critically evaluate the accuracy and completeness of the paleoseismictrenching data, particularly regarding earthquake timing and displacement, (2) where the data permit, assign consensus, preferred recurrence-interval (RI) and vertical slip-rate (VSR) estimates with appropriate confidence limits to the faults/fault sections under review, and (3) identify critical gaps in the paleoseismic data and recommend where and what kinds of additional paleoseismic studies should be performed to ensure that Utah’s earthquake hazard is adequately documented and understood. It is important to note that, with the exception of the Great Salt Lake fault zone, the Working Group’s review was limited to faults/fault sections having paleoseismic-trenching data. Most Quaternary faults/fault sections in Utah have not been trenched, but many have RI and VSR estimates based on tectonic geomorphology or other non-trench-derived studies. Black and others compiled the RI and VSR data for Utah’s Quaternary faults, both those with and without trenches.

Author: Jascha A. Coddington
Publisher:
ISBN:
Category :
Languages : en
Pages : 336

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Fault-related folding is a widely-observed process in the upper crust associated with growth of mountain ranges within active organic systems. The Tien Shan is one example of an active mountain range where fault-related folding is shaping the landscape. Several intermontane basins within this mountain belt exhibit active faulting and folding including the Jumgal Basin, which is the focus of this study. There are two fault zones determined to be active in the Jumgal Basin including the intra-basin structure and a basin-bounding reverse fault that splays basinward from a principal range-bounding fault. Placing constraints on the type of fault-related deformation is difficult using surface bedrock geometry alone. Studying the geometry of actively deforming fluvial terraces, which give incremental and temporal snapshots of deformation is useful for determining the geometry and kinematics of an active fault. The Jumgal Basin located in the Kyrgyz Tien Shan has a prominent anticline that exhibits well-preserved deformed fluvial terraces within several water gaps along strike. These actively deforming terraces were surveyed using a global positioning system (GPS) unit to quantify the progressive deformation of terraces emplaced over the mapped Neogene and Quaternary stratigraphic units. At the eastern end of the 20-km long project area the abandoned terraces exhibit predominantly limb lengthening, indicative of fault-bend folding with a discrete synclinal axial surface bounding the well-preserved terrace backlimbs. In the central and western portions of the study area the abandoned fluvial terraces exhibit progressive steepening of the older terraces. Progressive limb rotation at Aral is indicative of slip above a broadly curved fault. The zone of fault-related folding broadens westward along strike from less than 400 m at Chaek to roughly 1800 m at Aral. Tilting of terraces increases eastward along strike from roughly 2° at Aral to roughly 18° at Chaek. Slip along the active faults was calculated using kinematic models of fault-bend folding, listric faulting, and emergent thrust-faulting, as appropriate. Uncertainties of the observed bedrock and deformed terrace geometry were also propagated into calculations of dip-slip. Numerical ages of abandoned terraces in the Jumgal basin were correlated using a combination surveyed terrace profiles and 14C ages, which are