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Coastal Water Levels
Guidance for Flood Risk Analysis and Mapping Coastal Water Levels May 2016 Requirements for the Federal Emergency Management Agency (FEMA) Risk Mapping, Assessment, and Planning (Risk MAP) Program are specified separately by statute, regulation, or FEMA policy (primarily the Standards for Flood Risk Analysis and Mapping). This document provides guidance to support the requirements and recommends approaches for effective and efficient implementation. Alternate approaches that comply with all requirements are acceptable. For more information, please visit the FEMA Guidelines and Standards for Flood Risk Analysis and Mapping webpage (www.fema.gov/guidelines-and-standards-flood-risk-analysis-and- mapping). Copies of the Standards for Flood Risk Analysis and Mapping policy, related guidance, technical references, and other information about the guidelines and standards development process are all available here. You can also search directly by document title at www.fema.gov/library. Water Levels May 2016 Guidance Document 67 Page i Document History Affected Section or Date Description Subsection Initial version of new transformed guidance. The content was derived from the Guidelines and Specifications for Flood Hazard Mapping Partners, Procedure Memoranda, First Publication May 2016 and/or Operating Guidance documents. It has been reorganized and is being published separately from the standards. Water Levels May 2016 Guidance Document 67 Page ii Table of Contents 1.0 Topic Overview ................................................................................................................. -
Tsunami, Seiches, and Tides Key Ideas Seiches
Tsunami, Seiches, And Tides Key Ideas l The wavelengths of tsunami, seiches and tides are so great that they always behave as shallow-water waves. l Because wave speed is proportional to wavelength, these waves move rapidly through the water. l A seiche is a pendulum-like rocking of water in a basin. l Tsunami are caused by displacement of water by forces that cause earthquakes, by landslides, by eruptions or by asteroid impacts. l Tides are caused by the gravitational attraction of the sun and the moon, by inertia, and by basin resonance. 1 Seiches What are the characteristics of a seiche? Water rocking back and forth at a specific resonant frequency in a confined area is a seiche. Seiches are also called standing waves. The node is the position in a standing wave where water moves sideways, but does not rise or fall. 2 1 Seiches A seiche in Lake Geneva. The blue line represents the hypothetical whole wave of which the seiche is a part. 3 Tsunami and Seismic Sea Waves Tsunami are long-wavelength, shallow-water, progressive waves caused by the rapid displacement of ocean water. Tsunami generated by the vertical movement of earth along faults are seismic sea waves. What else can generate tsunami? llandslides licebergs falling from glaciers lvolcanic eruptions lother direct displacements of the water surface 4 2 Tsunami and Seismic Sea Waves A tsunami, which occurred in 1946, was generated by a rupture along a submerged fault. The tsunami traveled at speeds of 212 meters per second. 5 Tsunami Speed How can the speed of a tsunami be calculated? Remember, because tsunami have extremely long wavelengths, they always behave as shallow water waves. -
Downloaded 09/24/21 11:26 AM UTC 966 JOURNAL of PHYSICAL OCEANOGRAPHY VOLUME 46
MARCH 2016 G R I M S H A W E T A L . 965 Modelling of Polarity Change in a Nonlinear Internal Wave Train in Laoshan Bay ROGER GRIMSHAW Department of Mathematical Sciences, Loughborough University, Loughborough, United Kingdom CAIXIA WANG AND LAN LI Physical Oceanography Laboratory, Ocean University of China, Qingdao, China (Manuscript received 23 July 2015, in final form 29 December 2015) ABSTRACT There are now several observations of internal solitary waves passing through a critical point where the coefficient of the quadratic nonlinear term in the variable coefficient Korteweg–de Vries equation changes sign, typically from negative to positive as the wave propagates shoreward. This causes a solitary wave of depression to transform into a train of solitary waves of elevation riding on a negative pedestal. However, recently a polarity change of a different kind was observed in Laoshan Bay, China, where a periodic wave train of elevation waves converted to a periodic wave train of depression waves as the thermocline rose on a rising tide. This paper describes the application of a newly developed theory for this phenomenon. The theory is based on the variable coefficient Korteweg–de Vries equation for the case when the coefficient of the quadratic nonlinear term undergoes a change of sign and predicts that a periodic wave train will pass through this critical point as a linear wave, where a phase change occurs that induces a change in the polarity of the wave, as observed. A two-layer model of the density stratification and background current shear is developed to make the theoretical predictions specific and quantitative. -
Fault Model of the 12Th Century Southwestern Hokkaido Earthquake
Ioki et al. Earth, Planets and Space (2019) 71:54 https://doi.org/10.1186/s40623-019-1034-6 FULL PAPER Open Access Fault model of the 12th century southwestern Hokkaido earthquake estimated from tsunami deposit distributions Kei Ioki1* , Yuichiro Tanioka2, Gentaro Kawakami3, Yoshihiro Kase3, Kenji Nishina3, Wataru Hirose3, Kei’ichi Hayashi3 and Ryo Takahashi3 Abstract Tsunami deposits were collected along the coast of southwestern Hokkaido and Okushiri Island, northern Japan. The distribution of these deposits suggested that large earthquakes and tsunamis have repeatedly occurred of south- western Hokkaido. Along the southern coast of Okushiri Island, fve tsunami sand/gravel layers have been deposited during the last 3000 years. The latest was deposited by the 1741 Oshima–Oshima landslide tsunami and the second by the 12th century tsunami. The later tsunami was probably generated by a large earthquake because submarine seismo-turbidites with similar age exist in the region and a large inland landslide had occurred in Okushiri Island in approximately the 12th century. The ages of paleo-tsunami events prior to the 12th century are 1.5–1.6, 2.4–2.6, 2.8–3.1 ka. In this study, a fault model of the 12th century earthquake was estimated by comparing tsunami deposit distributions and calculated tsunami inundation areas at fve sites in Okushiri Island and Hiyama region. Fault model F17, a submarine active fault in the Japan Sea near Oshima–Oshima, is a probable source for this tsunami. Numerical simulation of the tsunami was performed based on fault model F17; we modifed the fault parameters (length and slip amount) from the original model to explain tsunami deposit distributions. -
Part II-1 Water Wave Mechanics
Chapter 1 EM 1110-2-1100 WATER WAVE MECHANICS (Part II) 1 August 2008 (Change 2) Table of Contents Page II-1-1. Introduction ............................................................II-1-1 II-1-2. Regular Waves .........................................................II-1-3 a. Introduction ...........................................................II-1-3 b. Definition of wave parameters .............................................II-1-4 c. Linear wave theory ......................................................II-1-5 (1) Introduction .......................................................II-1-5 (2) Wave celerity, length, and period.......................................II-1-6 (3) The sinusoidal wave profile...........................................II-1-9 (4) Some useful functions ...............................................II-1-9 (5) Local fluid velocities and accelerations .................................II-1-12 (6) Water particle displacements .........................................II-1-13 (7) Subsurface pressure ................................................II-1-21 (8) Group velocity ....................................................II-1-22 (9) Wave energy and power.............................................II-1-26 (10)Summary of linear wave theory.......................................II-1-29 d. Nonlinear wave theories .................................................II-1-30 (1) Introduction ......................................................II-1-30 (2) Stokes finite-amplitude wave theory ...................................II-1-32 -
New Constraints on Coseismic Slip During Southern Cascadia Subduction Zone Earthquakes Over the Past 4600 Years Implied by Tsunami Deposits and Marine Turbidites
W&M ScholarWorks VIMS Articles Virginia Institute of Marine Science 2018 New constraints on coseismic slip during southern Cascadia subduction zone earthquakes over the past 4600 years implied by tsunami deposits and marine turbidites GR Priest RC Witter Yinglong J. Zhang Virginia Institute of Marine Science C Goldfinger KL Wang See next page for additional authors Follow this and additional works at: https://scholarworks.wm.edu/vimsarticles Part of the Aquaculture and Fisheries Commons Recommended Citation Priest, GR; Witter, RC; Zhang, Yinglong J.; Goldfinger, C; Wang, KL; and Allen, JC, "New constraints on coseismic slip during southern Cascadia subduction zone earthquakes over the past 4600 years implied by tsunami deposits and marine turbidites" (2018). VIMS Articles. 734. https://scholarworks.wm.edu/vimsarticles/734 This Article is brought to you for free and open access by the Virginia Institute of Marine Science at W&M ScholarWorks. It has been accepted for inclusion in VIMS Articles by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. Authors GR Priest, RC Witter, Yinglong J. Zhang, C Goldfinger, KL Wang, and JC Allen This article is available at W&M ScholarWorks: https://scholarworks.wm.edu/vimsarticles/734 Nat Hazards (2017) 88:285–313 DOI 10.1007/s11069-017-2864-9 ORIGINAL PAPER New constraints on coseismic slip during southern Cascadia subduction zone earthquakes over the past 4600 years implied by tsunami deposits and marine turbidites 1 2 3 George R. Priest • Robert C. Witter • Yinglong J. Zhang • 4 5 1 Chris Goldfinger • Kelin Wang • Jonathan C. Allan Received: 24 August 2016 / Accepted: 8 April 2017 / Published online: 29 April 2017 Ó Springer Science+Business Media Dordrecht (outside the USA) 2017 Abstract Forecasting earthquake and tsunami hazards along the southern Cascadia sub- duction zone is complicated by uncertainties in the amount of megathrust fault slip during past ruptures. -
A Review of Geological Records of Large Tsunamis at Vancouver Island, British Columbia, and Implications for Hazard John J
Quaternary Science Reviews 19 (2000) 849}863 A review of geological records of large tsunamis at Vancouver Island, British Columbia, and implications for hazard John J. Clague! " *, Peter T. Bobrowsky#, Ian Hutchinson$ !Depatment of Earth Sciences and Institute for Quaternary Research, Simon Fraser University, Burnaby, BC, Canada V5A 1S6 "Geological Survey of Canada, 101 - 605 Robson St., Vancouver, BC, Canada V6B 5J3 #Geological Survey Branch, P.O. Box 9320, Stn Prov Govt, Victoria, BC, Canada V8W 9N3 $Department of Geography and Institute for Quaternary Research, Simon Fraser University, Burnaby, Canada BC V5A 1S6 Abstract Large tsunamis strike the British Columbia coast an average of once every several hundred years. Some of the tsunamis, including one from Alaska in 1964, are the result of distant great earthquakes. Most, however, are triggered by earthquakes at the Cascadia subduction zone, which extends along the Paci"c coast from Vancouver Island to northern California. Evidence of these tsunamis has been found in tidal marshes and low-elevation coastal lakes on western Vancouver Island. The tsunamis deposited sheets of sand and gravel now preserved in sequences of peat and mud. These sheets commonly contain marine fossils, and they thin and "ne landward, consistent with deposition by landward surges of water. They occur in low-energy settings where other possible depositional processes, such as stream #ooding and storm surges, can be ruled out. The most recent large tsunami generated by an earthquake at the Cascadia subduction zone has been dated in Washington and Japan to AD 1700. The spatial distribution of the deposits of the 1700 tsunami, together with theoretical numerical modelling, indicate wave run-ups of up to 5 m asl along the outer coast of Vancouver Island and up to 15}20 m asl at the heads of some inlets. -
The Kingdom of Tonga Devastated by a Megatsunami in the Mid-15Th Century
EGU21-5317, updated on 25 Sep 2021 https://doi.org/10.5194/egusphere-egu21-5317 EGU General Assembly 2021 © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. The kingdom of Tonga devastated by a megatsunami in the mid-15th century Franck Lavigne1,2,3, Julie Morin4, Wassmer Patrick2, Weller Olivier5, Kula Taaniela6, Ana V. Maea6, Karim Kelfoun7, Fatima Mokadem2, Raphael Paris7, Mukhamad N. Malawani1,2,8, Faral Audrey1,2, Mhammed Benbakkar7, Ségolène Saulnier-Copard2, Céline M. Vidal4, Tu’I’ahai Tu’I’afitu6, Gomez Christopher9, and Fuka Kitekei’aho10 1Paris 1 Pantheon-Sorbonne University, ([email protected]) 2Laboratory of Physical Geography, UMR 8591 CNRS, Meudon, France 3Institut Universitaire de France, Paris, France 4Department of Geography, University of Cambridge, Cambridge, UK 5Trajectoires, UMR 8215 CNRS, Paris, France 6Ministry of Land and Natural Resources, Natural Resources Division, Nuku'alofa, Kingdom of Tonga 7Laboratoire Magmas et Volcans, Université Clermont Auvergne, CNRS, IRD, OPGC, France 8Faculty of Geography, Universitas Gadjah Mada, Yogyakarta, Indonesia 9Laboratory of Sediment Hazards and Disaster Risk, Kobe University, Japan 10Geocare & Petroleum Consult Ltd, Nuku'alofa, Kingdom of Tonga The pre-colonial history of Tonga and West Polynesia still suffers from major gaps because its reconstruction is essentially based on legends left by oral tradition, and by archaeological evidence somehow difficult to interpret. By the fourteenth century, the powerful Tu'i Tonga kingdom united the islands of the Tongan archipelago under a centralised authority and, according to tradition, extended its influence to neighbouring island groups in the Central Pacific. However, some periods of deep crisis were identified, e.g. -
Historical and Paleo-Tsunami Deposits During the Last 4000 Years and Their
Ishimura and Miyauchi Progress in Earth and Planetary Science (2015) 2:16 DOI 10.1186/s40645-015-0047-4 RESEARCH ARTICLE Open Access Historical and paleo-tsunami deposits during the last 4000 years and their correlations with historical tsunami events in Koyadori on the Sanriku Coast, northeastern Japan Daisuke Ishimura1* and Takahiro Miyauchi2 Abstract Large tsunamis occurring throughout the past several hundred years along the Sanriku Coast on the Pacific coast of northeastern Japan have been documented and observed. However, the risk of large tsunamis like the tsunami generated by the 2011 off the Pacific coast of Tohoku earthquake could not be evaluated from previous studies, because these studies lacked evidence of historical and paleo-tsunami deposits on the coastline. Thus, we first identified event deposits, which are candidates for tsunami deposits, from excavating surveys conducted on the coastal marsh in Koyadori on the Sanriku Coast, northeastern Japan. Second, we determined the physicochemical sediment properties of the deposits (roundness of grains, color, wet and dry densities, and loss on ignition) and established their geochronology by radiocarbon dating and tephra analysis. Third, we identified event deposits as tsunami deposits, based on their sedimentary features and origin, sedimentary environment, paleo-shoreline, and landowner interviews. In this study, we report 11 tsunami deposits (E1–E11) during the past 4000 years, of which E1, E2, E3, and E4 were correlated with the 2011 Tohoku-oki tsunami, the 1896 Meiji Sanriku tsunami, the 1611 Keicho Sanriku tsunami, and the 869 Jogan tsunami, respectively. From age data and the number of tsunami deposits in the trench, we estimated that tsunamis larger than the 1896 Meiji Sanriku tsunami occur and hit the study area on average every 290–390 years. -
Literature Review of Tsunami Sources Affecting Tsunami Hazard Along the US East Coast
Literature review of tsunami sources affecting tsunami hazard along the US East Coast Department of Ocean Engineering, University of Rhode Island Narragansett, USA Feb. 21, 2011 1 TABLE OF CONTENTS 1. BACKGROUND ...................................................................................................................... 3 2. LITERATURE REVIEW OF RELEVANT TSUNAMI SOURCES .................................... 5 2.1 Submarine Mass Failures ........................................................................................................ 5 2.2 Co-seismic tsunamis .................................................................................................................. 8 2.2.1 Review of literature on Caribbean subduction zone ............................................................. 8 2.2.2 NOAA Forecast Source Database for Caribbean subduction zone ............................... 16 2.2.3 Azores-Gibraltar convergence zone .......................................................................................... 17 2.3 Cumbre Vieja Volcano flanK collapse ............................................................................... 21 3. INITIAL SOURCE DEFINITIONS AND TSUNAMI SIMULATIONS .......................... 24 3.1 Modeling methodology .......................................................................................................... 24 3.1.1 Initial conditions for model .......................................................................................................... 24 3.1.2 Co-seismic sources -
Engineering Geology and Seismology for Public Schools and Hospitals in California
The Resources Agency California Geological Survey Michael Chrisman, Secretary for Resources Dr. John G. Parrish, State Geologist Engineering Geology and Seismology for Public Schools and Hospitals in California to accompany California Geological Survey Note 48 Checklist by Robert H. Sydnor, Senior Engineering Geologist California Geological Survey www.conservation.ca.gov/cgs July 1, 2005 316 pages Engineering Geology and Seismology performance–based analysis, diligent subsurface for Public Schools and Hospitals sampling, careful reading of the extensive geologic in California literature, thorough knowledge of the California Building Code, combined with competent professional geological work. by Robert H. Sydnor Engineering geology aspects of hospital and public California Geological Survey school sites include: regional geology, regional fault July 1, 2005 316 pages maps, site-specific geologic mapping, geologic cross- sections, active faulting, official zones of investigation Abstract for liquefaction and landslides, geotechnical laboratory The 446+ hospitals, 1,400+ skilled nursing facilities testing of samples, expansive soils, soluble sulfate ±9,221 public schools, and 109 community college evaluation for Type II or V Portland-cement selection, campuses in California are regulated under California and flooding. Code of Regulations, Title 24, California Building Code. Seismology aspects include: evaluation of historic These facilities are plan–checked by senior–level seismicity, probabilistic seismic hazard analysis of Registered Structural Engineers within the Office of earthquake ground–motion, use of proper code terms Statewide Health Planning and Development (OSHPD) (Upper–Bound Earthquake ground–motion and Design– for hospitals and skilled nursing facilities, and the Basis ground–motion), classification of the geologic Division of the State Architect (DSA) for public schools, subgrade by shear–wave velocity to select the correct community colleges, and essential services buildings. -
Shallow Water Waves and Solitary Waves Article Outline Glossary
Shallow Water Waves and Solitary Waves Willy Hereman Department of Mathematical and Computer Sciences, Colorado School of Mines, Golden, Colorado, USA Article Outline Glossary I. Definition of the Subject II. Introduction{Historical Perspective III. Completely Integrable Shallow Water Wave Equations IV. Shallow Water Wave Equations of Geophysical Fluid Dynamics V. Computation of Solitary Wave Solutions VI. Water Wave Experiments and Observations VII. Future Directions VIII. Bibliography Glossary Deep water A surface wave is said to be in deep water if its wavelength is much shorter than the local water depth. Internal wave A internal wave travels within the interior of a fluid. The maximum velocity and maximum amplitude occur within the fluid or at an internal boundary (interface). Internal waves depend on the density-stratification of the fluid. Shallow water A surface wave is said to be in shallow water if its wavelength is much larger than the local water depth. Shallow water waves Shallow water waves correspond to the flow at the free surface of a body of shallow water under the force of gravity, or to the flow below a horizontal pressure surface in a fluid. Shallow water wave equations Shallow water wave equations are a set of partial differential equations that describe shallow water waves. 1 Solitary wave A solitary wave is a localized gravity wave that maintains its coherence and, hence, its visi- bility through properties of nonlinear hydrodynamics. Solitary waves have finite amplitude and propagate with constant speed and constant shape. Soliton Solitons are solitary waves that have an elastic scattering property: they retain their shape and speed after colliding with each other.