Summary and Categorization of Documented Geologic Hazards of the National Park System
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5.4.5 Geological Hazards
Section 5.4.5: Risk Assessment – Geological Hazards 5.4.5 Geological Hazards The following section provides the hazard profile (hazard description, location, extent, previous occurrences and losses, probability of future occurrences, and impact of climate change) and vulnerability assessment for the geological hazards in Sussex County. 2016 Plan Update Changes The hazard profile has been significantly enhanced to include a detailed hazard description, location, extent, previous occurrences, probability of future occurrence, and potential change in climate and its impacts on the geological hazards is discussed. The geological hazards is now located in Section 5 of the plan update. It includes landslide, land subsidence and sinkholes, all of which were profiled separately in the 2011 HMP. New and updated figures from federal and state agencies are incorporated. U.S. 2010 Census data was incorporated, where appropriate. Previous occurrences were updated with events that occurred between 2008 and 2015. A vulnerability assessment was conducted for the geological hazards and it now directly follows the hazard profile. 5.4.5.1 Profile Hazard Description Geological hazards are any geological or hydrological processes that pose a threat to humans and natural properties. Every year, severe natural events destroy infrastructure and cause injuries and deaths. Geologic hazards may include volcanic eruptions and other geothermal related features, earthquakes, landslides and other slope failures, mudflows, sinkhole collapses, snow avalanches, flooding, glacial surges and outburst floods, tsunamis, and shoreline movements. For the purpose of this HMP update, only landslides and land subsidence/sinkholes will be discussed in the Geological Hazard profile. Landslides According to the U.S. -
Beyond the Angle of Repose: a Review and Synthesis of Landslide Processes in Response to Rapid Uplift, Eel River, Northern Eel River, Northern California
Portland State University PDXScholar Geology Faculty Publications and Presentations Geology 2-23-2015 Beyond the Angle of Repose: A Review and Synthesis of Landslide Processes in Response to Rapid Uplift, Eel River, Northern Eel River, Northern California Joshua J. Roering University of Oregon Benjamin H. Mackey University of Canterbury Alexander L. Handwerger University of Oregon Adam M. Booth Portland State University, [email protected] Follow this and additional works at: https://pdxscholar.library.pdx.edu/geology_fac David A. Schmidt Univ Persityart of of the W Geologyashington Commons , Geomorphology Commons, and the Geophysics and Seismology Commons Let us know how access to this document benefits ou.y See next page for additional authors Citation Details Roering, Joshua J., Mackey, Benjamin H., Handwerger, Alexander L., Booth, Adam M., Schmidt, David A., Bennett, Georgina L., Cerovski-Darriau, Corina, Beyond the angle of repose: A review and synthesis of landslide pro-cesses in response to rapid uplift, Eel River, Northern California, Geomorphology (2015), doi: 10.1016/j.geomorph.2015.02.013 This Post-Print is brought to you for free and open access. It has been accepted for inclusion in Geology Faculty Publications and Presentations by an authorized administrator of PDXScholar. Please contact us if we can make this document more accessible: [email protected]. Authors Joshua J. Roering, Benjamin H. Mackey, Alexander L. Handwerger, Adam M. Booth, David A. Schmidt, Georgina L. Bennett, and Corina Cerovski-Darriau This post-print is available at PDXScholar: https://pdxscholar.library.pdx.edu/geology_fac/75 ACCEPTED MANUSCRIPT Beyond the angle of repose: A review and synthesis of landslide processes in response to rapid uplift, Eel River, Northern California Joshua J. -
Geology and Seismicity
SECTIONNINE GEOLOGY AND SEISMICITY 9. Section 9 NINE Geology and Seismicity This section describes the major geologic regions that could be affected by project construction and operation and the potential environmental consequences of the alternatives. 9.1 AFFECTED ENVIRONMENT The following paragraphs summarize the geologic conditions and hazards that may be encountered during the construction and implementation of the alternatives for the San Luis Drainage Feature Re-evaluation. The geologic environment is discussed in greater detail in Appendix H. The focus of this section is the geologic and seismic characteristics of the Great Valley and the Coast Ranges geomorphic provinces, which may influence the comparison of a the action alternatives due to the geologic conditions and potential geologic hazards associated with these regions. 9.1.1 Regulatory Background Several Federal and State regulations govern geology, seismicity, and soils in California. The Federal actions include the Earthquake Hazard Reduction Act of 1977, Executive Order 12699 on Seismic Safety of Federal Buildings, and the Uniform Building Code (superceded in California by the California Building Code). The State actions include the Alquist-Priolo Act, the Field Act, the California Building Code, and the Seismic Hazards Mapping Act. Some State agencies, including California Department of Transportation (Caltrans) and California Department of Water Resources (DWR), Division of Safety of Dams, have their own actions covering seismic and geologic hazards. In addition, municipalities and counties can have general or specific plans that may include the need for permitting. The regulatory background governing geology, seismicity, and soils is discussed further in Section 4.6. SLDFR Final EIS Section 09_Geology 9-1 SECTIONNINE Geology and Seismicity 9.1.2 Geologic Setting The existing San Luis Drain is situated near the western margin of San Joaquin Valley (Figure 9-1), which comprises the southern region of the Great Valley geomorphic province (Harden 1998). -
Coastal and Other Hazards (Se)
Goleta General Plan /Coastal Land Use Plan 5.0 Safety Element CHAPTER 5.0 SAFETY ELEMENT: COASTAL AND OTHER HAZARDS (SE) 5.1 INTRODUCTION General Plan Law Requirements [GP] The Safety Element is one of seven general Safety Element Policies plan elements mandated by state law. The SE 1: Safety in General scope of the Safety Element is specified in SE 2: Bluff Erosion and Retreat Section 65302 (g) of the California SE 3: Beach Erosion and Shoreline Hazards SE 4: Seismic and Seismically Induced Hazards Government Code as follows: SE 5: Soil and Slope Stability Hazards SE 6: Flood Hazards The general plan shall include a safety SE 7: Urban and Wildland Fire Hazards element for the protection of the SE 8: Oil and Gas Industry Hazards community from any unreasonable SE 9: Airport-Related Hazards. SE 10: Hazardous Materials and Facilities risks associated with the effects of SE 11: Emergency Preparedness seismically induced surface rupture, ground shaking, ground failure, tsunami, seiche, and dam failure; slope instability leading to mudslides and landslides; subsidence and other geologic hazards known to the legislative body; flooding; and wild land and urban fires. The safety element shall include mapping of known seismic and other geologic hazards. It shall also address evacuation routes, peak-load water supply requirements, and minimum road widths and clearances around structures, as those items relate to identified fire and geologic hazards. Coastal hazards such as bluff retreat and shoreline erosion are also addressed in this element, as are hazards associated with oil and gas production, processing, and transport. California Coastal Act Requirements [CP] The California Coastal Act (Coastal Act) requires new development to be sited and designed to minimize risks, ensure stability and structural integrity, and neither create nor contribute significantly to erosion or require the construction of new shoreline protective devices that would substantially alter natural landforms along coastal bluffs and cliffs. -
BAER) Assessment Specialist Report, Phase 2 – GEOLOGIC HAZARDS
Burned Area Emergency Response (BAER) Assessment Specialist Report, Phase 2 – GEOLOGIC HAZARDS Thomas Fire, Los Padres National Forest January 2018 Allen King – Geologist, Los Padres NF (retired) Dennis Veich – Forest Geologist, Shasta-Trinity NF Fire-damaged Tree near Chismahoo Mountain “When rain starts to fall, people in higher risk basins should be prepared to evacuate. Do not remain in, near or below burned areas at the base of canyons, even during light rain. Stay away from small streams that could become raging rivers in the blink of an eye. If the forecast calls for heavy rains through the night, homes may not be safe places if they are located in or near drainage areas and within a mile of the mountain front. Roads can suddenly become blocked with mud and debris, and can wash out at stream crossings. It is important to pay strong attention to warnings from local emergency responders and weather advisories.” -Sue Cannon, USGS Landslide Hazards Program, 2003 INTRODUCTION The Thomas Fire started on December 4, 2017, near the Thomas Aquinas College (east end of Sulphur Mountain), Ventura County, California. The fire is still considered to be active and as of January 12th, 2018, it is estimated to have burned 281,900 acres and is 92% contained. Approximately 181,300 acres within the burn area are National Forest lands (~64%); 98,200 acres are private (~35%); and 2,400 acres (~1%) are a combination of state and county properties. Although tremendous down-slope/down-drainage resources and values and lives are recognized and kept in mind during our analysis, this report addresses the effects of the Thomas Fire and the associated Values At Risk (VARs) ONLY on Forest Service lands, since the other lands are being evaluated by teams of Cal Fire scientists and other agencies. -
Mass Wasting and Hill-Slopes Mass Wasting
Mass Wasting and Hill-slopes Mass wasting • Is a collective term addressing all down slope movements of weathered rock (soil) that are created by gravitational forces. • Gravity is the primary component! • Vocabulary – Colluvium – Solifluction (soil flow) The Angle of Repose • The maximum slope at which loose, cohesionless material remains stable. It commonly ranges between 33 and 37 on natural slopes. • Dependent upon size, shape, surface roughness, angularity, of the particles • Wallace Stegner book as well. Dry sand cannot support an angle of >35o from horizontal: this is termed the angle of repose. 35o Moderate amounts of water create Saturation of sediment by increased structural integrity of water eliminates any structural sediment due to surface tension competence. This is the between grains. In this way slopes condition that often leads to steeper than the angle of repose can slope instability and be maintained (e.g., sandcastles). mass wasting. Slope movement types • When defining mass wasting it is necessary to include 1) the type of material in motion, including its coherence and dimensions; and 2) the type and rate of movement including creeping, falling, toppling, sliding, spreading, or flowing (debris flow). Handout Creep • Barely perceptible down slope movement. • Particle creep, individual particle movement due to wetting/drying, heating/cooling • Soil creep, dependent on changing SMR and climates. Creepy drawing Creep (or soil creep) works at a pace of mm/yr. It is generally related to (seasonal) wet-dry or freeze thaw changes. Fall • A fall is a mass movement where singular or multiple blocks of rock plunge from a height. Yosemite, CA Looks like an ideal place for a rock fall or a rock slide, thanks to exfoliation of granite batholiths. -
Mass Wasting and Landslides
Mass Wasting and Landslides Mass Wasting 1 Introduction Landslide and other ground failures posting substantial damage and loss of life In U.S., average 25–50 deaths; damage more than $3.5 billion For convenience, definition of landslide includes all forms of mass-wasting movements Landslide and subsidence: naturally occurred and affected by human activities Mass wasting Downslope movement of rock and soil debris under the influence of gravity Transportation of large masses of rock Very important kind of erosion 2 Mass wasting Gravity is the driving force of all mass wasting Effects of gravity on a rock lying on a hillslope 3 Boulder on a hillside Mass Movement Mass movements occur when the force of gravity exceeds the strength of the slope material Such an occurrence can be precipitated by slope-weakening events Earthquakes Floods Volcanic Activity Storms/Torrential rain Overloading the strength of the rock 4 Mass Movement Can be either slow (creep) or fast (landslides, debris flows, etc.) As terrain becomes more mountainous, the hazard increases In developed nations impacts of mass-wasting or landslides can result in millions of dollars of damage with some deaths In less developed nations damage is more extensive because of population density, lack of stringent zoning laws, scarcity of information and inadequate preparedness **We can’t always predict or prevent the occurrence of mass- wasting events, a knowledge of the processes and their relationship to local geology can lead to intelligent planning that will help -
Seismic Design Guidelines Appendix B: Geotechnical
Mandatory Retrofit Program for Non-Ductile Concrete Buildings And Pre-Northridge Steel Moment Frame Buildings Ordinance 17-1011 SEISMIC DESIGN GUIDELINES APPENDIX B ISSUED NOVEMBER 8, 2019 REVISED SEPTEMBER 25, 2020 APPENDIX B: GEOTECHNICAL / GEOLOGICAL REPORT REQUIREMENTS 1.0 INTRODUCTION ASCE 41 geotechnical/geological report requirements for seismic evaluation and retrofit design varies greatly based on the amount of as-built information obtained and type of existing foundation system. The following document is intended to help clarify geotechnical / geological requirements of Ordinance 17-1011 for Non-Ductile Concrete and Pre-Northridge Steel Moment Frames. It is noted that all geotechnical / geological reports shall be signed and stamped by a California licensed Geotechnical Engineer and by a California licensed Geologist (if applicable). 2.0 SEISMIC SITE HAZARD The following frequently asked questions and answers are intended to clarify the scope and requirements of the seismic site hazard requirements of Ordinance 17-1011. 2.1 When is a site-specific seismic hazard determination required? A site-specific seismic hazard procedure is required when: a. The building is located on Site Class E soils and the mapped BSE-2N Sxs>2.0 or b. The building is located on Site Class F soils, unless Ss<0.20. In addition, a site-specific hazard is required to scale records when performing a non- linear dynamic time-history analysis. [Ref. ASCE 41 Section 2.4]. 2.2 When scaling a suite of acceleration records, is there a required or preferred scaling method? A site-specific response spectra shall be developed per ASCE 41 Section 2.4.2.1 requirements. -
Mass-Wasting, Classification and Damage in Ohio C
MASS-WASTING, CLASSIFICATION AND DAMAGE IN OHIO C. N. SAVAGE Department of Geography and Geology, Kent State University, Kent, Ohio The sudden and often spectacular free fall, slide, flow, creep or subsidence of earth materials may be costly in terms of human lives and property damage. Phenomena of this type, variously called "landslide, earthflow or subsidence" are assigned by geologists to gravity controlled movement or referred to collectively as "mass-wasting." This category also includes movement of dry or hard-frozen masses, or snow-laden debris when moved by gravity. Figure 1 illustrates some of these types of movement. This paper is intended to bring to the attention of laymen and professional men the importance and widespread occurrence of these destructive forces. A brief discussion of damage, origin, prevention and classification is presented, followed by examples in Ohio. It is hoped that the suggested classification will prove useful as an aid to the recognition of different types of mass-movement. Annually, many highways are blocked or destroyed, soils are ruined and buried in rubble, forest lands are ripped apart, and bridges, dams, buildings and other structures are wrecked or buried by landslides. Every year, especially in southern and eastern Ohio, many thousands of dollars are lost because of this type of calamity. There is scarcely a spring which does not bring reports of landslides in the local press. It seems obvious that this is a subject of grave concern to construction engineers, soils experts, conservation men and many others including the tax paying citizen. Wherever there are slopes that are steep enough, and wherever there is loose rock material, mass-wasting is a potential threat. -
Identification and Mitigation of Geologic Hazards
AIPGprofessional geologists in all specialties of the science Identification and Mitigation of Geologic Hazards An important and practical application of and because earthquakes geology is identifying hazardous natural are of such a scale that phenomena and isolating their causes in they can affect several order to safeguard communities. According communities si-multane- to the USGS, the average economic toll ously, the risk to human life from natural hazards in the United States is is obvious.2 The largest approximately $52 billion per year, while recorded earthquake to hit the average annual death toll is approxi- the North American conti- mately 200.1 The primary causes are nent had a magnitude of earthquakes, landslides, and flooding, but 9.2, which occurred on other events, such as subsidence, volcanic March 27, 1964 in eruptions, and exposure to radon or asbes- Anchorage, Alaska. It dev- tos, also pose considerable danger. astated the town and sur- Awareness of the potential hazards that rounding area, and could persist in areas under consideration for be felt over an area of half Figure 2. Volcano Zones both private and community development a million square miles.2 is critical, and so geological consultants Land-slides caused most of the average global temperature by 2 and engineers are called in to survey land the damage, while a 30-foot high tsunami degrees Fahrenheit for 2 years.3 development sites and assist building con- generated by an underwater quake leveled tractors in designing structures that will coastal villages around the Gulf of Alaska, The role of geologists in mitigating such stand the test of time. -
Weathering: Big Ideas Mass Wasting
Weathering: Big Ideas • Humans cannot eliminate natural hazards but can engage in activities that reduce their impacts by identifying high-risk locations, improving construction methods, and developing warning systems. • Water’s unique physical and chemical properties are essential to the dynamics of all of Earth’s systems • Understanding geologic processes active in the modern world is crucial to interpreting Earth’s past • Earth’s systems are dynamic; they continually react to changing influences from geological, hydrological, physical, chemical, and biological processes. Mass Wasting Process by which material moves downslope under the force of gravity http://www.youtube.com/watch?v=qEbYpts0Onw Factors Influencing Mass Movement Nature of Steepness of Water Slope Slope Material Slope Content Stability 1 Mass Movement Depends on Nature of Material Angle of Repose: the maximum angle at which a pile of unconsolidated particles can rest The angle of repose increases with increasing grain size Fig. 16.13 Weathered shale forms rubble at base of cliff Angle of Repose Fig. 16.15 Origin of Surface Tension Water molecules in a …whereas surface liquids interior are molecules have a net attracted in all inward attraction that directions… results in surface tension… Fig. 16.13 2 …that acts like a membrane, allowing objects to float. Fig. 16.13 Mass Movement Depends on Water Content Surface tension in damp sand increases Dry sand is bound Saturated sand flows easily cohesion only by friction because of interstitial water Fig. 16.13 Steep slopes in damp sand maintained by moisture between grains Fig. 16.14 3 Loss of vegetation and root systems increases susceptibility of soils to erosion and mass movement Yellowstone National Park Before the 1964 Alaska Earthquake Water saturated, unconsolidated sand Fig. -
Type of Services Current Conditions Soils, Geology, and Geologic Hazards Envision San José 2040 General Plan Update
Type of Services Current Conditions Soils, Geology, and Geologic Hazards Envision San José 2040 General Plan Update Client David J. Powers & Associates Client Address 1885 The Alameda, Suite 204 San José, CA 95126 Project Number 118-13-2 Date March 20, 2009 Prepared Scott E. Fitinghoff, P.E., G.E. by Principal Geotechnical Engineer Philip A. Frame, C.E.G. Senior Engineering Geologist Laura C. Knutson, P.E., G.E. Principal Geotechnical Engineer Quality Assurance Reviewer Table of Contents SECTION 1: INTRODUCTION ......................................................................................... 1 1.1 PURPOSE ......................................................................................................... 1 SECTION 2: SOILS AND GEOLOGIC CONDITIONS ..................................................... 1 2.1 GEOLOGIC OVERVIEW OF SAN JOSÉ ......................................................... 1 2.2 LANDSLIDES ................................................................................................... 2 2.3 WEAK/EXPANSIVE SOILS .............................................................................. 3 2.4 NATURALLY-OCCURRING ABESTOS (NOA) ............................................... 4 2.5 EROSION .......................................................................................................... 4 2.6 ARTIFICIAL FILL .............................................................................................. 4 2.7 GROUND SUBSIDENCE DUE TO GROUND WATER REMOVAL ................. 4 2.8 MINERAL RESOURCES