DOCSLIB.ORG

Sea Hazards” Atmospheric Atmospheric Measurement Measurement E

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

EGU Journal Logos (RGB) Open Access Open Access Open Access Advances in Annales Nonlinear Processes Geosciences Geophysicae in Geophysics Open Access Open Access Nat. Hazards Earth Syst. Sci., 13, 1063–1067, 2013 Natural Hazards Natural Hazards www.nat-hazards-earth-syst-sci.net/13/1063/2013/ doi:10.5194/nhess-13-1063-2013 and Earth System and Earth System © Author(s) 2013. CC Attribution 3.0 License. Sciences Sciences Discussions Open Access Open Access Atmospheric Atmospheric Chemistry Chemistry and Physics and Physics Preface Discussions Open Access Open Access “Sea hazards” Atmospheric Atmospheric Measurement Measurement E. Pelinovsky1, I. Didenkulova2,3, F. Mendez4, D. Rybski5, and S. Tinti6 Techniques Techniques 1 Department of Nonlinear Geophysical Processes, Institute of Applied Physics, Nizhny Novgorod, Russia Discussions 2 Open Access Laboratory of Wave Engineering, Institute of Cybernetics, Tallinn University of Technology, Tallinn, Estonia Open Access 3Nizhny Novgorod State Technical University, Nizhny Novgorod, Russia 4 Environmental Hydraulics Institute “IH Cantabria”, Universidad de Cantabria, Santander,Biogeosciences Spain Biogeosciences 5Potsdam Institute for Climate Impact Research, Potsdam, Germany Discussions 6Dipartimento di Fisica e Astronomia, Universita` di Bologna, Bologna, Italy Open Access Correspondence to: I. Didenkulova ([email protected]) Open Access Climate Climate 1 Tsunamis finding on tsunami coastal distributionof the Past by Van Dorn (1965) of the Past and by Kajiura (1983) who studied tsunami events in Hawaii Discussions and in Japan, respectively. What is new in Choi et al.’s (2012) Tsunamis are the most known and most disastrous sea haz- Open Access analysis is that the log-normal distribution was proven to be Open Access ards and can occur in all world oceans as well as in closed fitted by the experimental data only when they are statisti- Earth System or almost closed seas like the Mediterranean. Interest in cally independent. This issueEarth was notSystem evident while handling tsunamis has substantially increased in the last few years, es- data of the historical tsunamisDynamics (1896 and 1933) since those Dynamics pecially after the case of the 2004 Indian Ocean tsunami that data were too few and referring to coastal places usually Discussions devastated the coasts of several near-field and far-field coun- several kilometers apart (which ensures their independence). tries and that claimed a death toll of about 220 thousands Instead, it came to light with the 2011 tsunami where the Open Access Open Access human lives mostly in Indonesia, India, Sri Lanka and Thai- space density of data is quiteGeoscientific larger (many observations were Geoscientific land. Since then and even more after the big Japan tsunami taken in locations very closeInstrumentation to each other). It was found that Instrumentation of 11 March 2011, the issues of what we can learn from to get statistical independence and log-normal distribution, past experiences and of how coastal communities can be pro- Methods and Methods and data should be averaged overData a scale Systems not smaller than 7.5 km, tected from the attack of catastrophic tsunamis have become which therefore can be taken as a sort of data correlation dis- Data Systems of paramount importance. tance. How this distance is related to basic geomorphologi- Discussions Open Access This SI collects a number of papers on the Tohoku tsunami Open Access cal features of the bathymetry and topography of the coastal Geoscientific that address different aspects of this event. Choi et al. (2012) zone is an issue still unresolved.Geoscientific study the run-up heights of the 2011 tsunami and compare The Tohoku tsunami hit the Japan coasts catastrophically, Model Development them with the data from the largest tsunamis that attacked Model Development but also reached significant wave heights in very distant Discussions the east Japanese coast in the last 150 yr, namely the Meiji coasts after travelling across the Pacific. Numerical codes Sanriku tsunami of 1896 and the Showa Sanriku tsunami Open Access for tsunami generation and propagation are indispensableOpen Access of 1933. The main interest of the authors was the study of tools to compute tsunamiHydrology radiation from and the source areas Hydrology and the space distribution of the run-up heights along the coast. and to provide adequate estimates of tsunami amplitude and Data are very abundant for the 2011 tsunami (more than travel times. In operationalEarth tsunami System warning systems, one Earth System 5000 data points) since the post-event surveys carried out by of the main constraints is time,Sciences since obviously predictions Sciences local experts and by international teams investigated the af- should be made and transmitted to the threatened commu- fected coastal areas (about 300 km long) with great accuracy. Discussions Open Access nities before the tsunami attacks. To meet thisOpen Access requirement, In contrast, the available observations for the 1896 and 1933 the most common strategy is to pre-compute a database of tsunamis are quite less (132 and 205, respectively). It was tsunami scenarios and, in case of tsunami occurrence, to ex- Ocean Science found that the space distribution of the observed run-ups is Ocean Science tract the case or cases that are most suited to (i.e. best fit) Discussions basically log-normal, which is a confirmation of the original Open Access Published by Copernicus Publications on behalf of the European Geosciences Union. Open Access Solid Earth Solid Earth Discussions Open Access Open Access The Cryosphere The Cryosphere Discussions 1064 E. Pelinovsky et al.: Preface “Sea hazards” the data from the monitoring networks. This strategy is moti- and Tinti noted that, though the highest values were mea- vated by the fact that tsunami simulations are usually very sured in the Japanese stations (close to the source; notice time-consuming and there would be no time to run simu- however that the tide gauges were destroyed and their data lations under an impending tsunami. Popinet (2012) argues went lost), there is no clear decrease of the tsunami height that adaptive codes can be used instead of fixed-grid numeri- with distance and very large heights (in excess of 2 m) were cal codes to cut down the computation time significantly even measured in some of the Hawaiian and of Chilean stations. for propagation over large oceanic areas, which can possibly Regional tsunami warning systems worldwide are today allow also real-time computations. Indeed Popinet uses an based on first reaction to large earthquakes. Though in gen- adaptive quadtree-based discretization algorithm to densify eral warning operations are quite complex and though dif- cells where it is dynamically needed, i.e. depending on the ferent procedures are established and followed by different characteristics of the tsunami waves, which reduces the total warning systems, the starting point of the operational proto- number of grid cells and hence of the required mathematical col is quite standard for most of them: i.e. the first decision operations. Whereas the computational cost of typical non- on tsunami occurrence is based on seismic data, more specif- flexible tsunami codes increases by a factor of 4 when the ically on the earthquake magnitude and hypocentral location, grid resolution doubles, adaptive methods tend to confine the since these determinations can be made in a few minutes cost increase to a factor of 2.60–2.65 (Popinet, 2011), which (less than 2–3 min) with the present level of technology by is a remarkable advantage. The application of this code to using seismic networks and seismic processing procedure of the Tohoku tsunami propagation in the near-field (with 250 m standard quality. Practically, a decision matrix is defined in resolution during flooding) and over long oceanic distances a way that, on entering earthquake magnitude, hypocentral (where cells size can be as big as 250 km) also provides re- depth and epicentral distance from the coast, it provides the sults in satisfactory agreement with the observations as re- alert level for the countries in the area covered by the warn- gards inundation on the Japan coasts and DART buoy records ing center. This first raw-decision bulletin can be later up- in the far-field. dated as a consequence of more sophisticated analyses made As already noted above, data for the 2011 Japan tsunami possible by the availability of more data. This strategy has are very abundant and indeed this is the tsunami event with also been defined and approved in the European region, i.e. the largest base of data recorded in the whole tsunami his- the last region in the world where tsunami warning centers tory, including coastal tide gauge and offshore buoy records. have been established and have started to be operational. Bressan and Tinti (2012) analyzed as many as 123 records of Here, the coordination body of the tsunami warning sys- tide gauges from most of the countries of the Pacific ocean to tems, called ICG/NEAMTWS (Intergovernmental Coordina- study tsunami changes in coastal waters and to test the per- tion Group for the North-East Atlantic and Mediterranean formance of the tsunami detection algorithm called TEDA: Tsunami Warning System), operating in the frame of the this is devised for real-time detection and is the combination IOC (Intergovernmental Oceanographic Commission) within of two threshold algorithms one based on time gradient and UNESCO, has adopted a specific decision
Recommended publications
  • Wind-Caused Waves Misleads Us Energy Is Transferred to the Wave

    Wind-Caused Waves Misleads Us Energy Is Transferred to the Wave

    WAVES IN WATER is quite similar. Most waves are created by the frictional drag of wind blowing across the water surface. A wave begins as Tsunami can be the most overwhelming of all waves, but a tiny ripple. Once formed, the side of a ripple increases the their origins and behaviors differ from those of the every­ day waves we see at the seashore or lakeshore. The familiar surface area of water, allowing the wind to push the ripple into waves are caused by wind blowing over the water surface. a higher and higher wave. As a wave gets bigger, more wind Our experience with these wind-caused waves misleads us energy is transferred to the wave. How tall a wave becomes in understanding tsunami. Let us first understand everyday, depends on (1) the velocity of the wind, (2) the duration of wind-caused waves and then contrast them with tsunami. time the wind blows, (3) the length of water surface (fetch) the wind blows across, and (4) the consistency of wind direction. Once waves are formed, their energy pulses can travel thou­ Wind-Caused Waves sands of kilometers away from the winds that created them. Waves transfer energy away from some disturbance. Waves moving through a water mass cause water particles to rotate in WHY A WIND-BLOWN WAVE BREAKS place, similar to the passage of seismic waves (figure 8.5; see Waves undergo changes when they move into shallow water­ figure 3.18). You can feel the orbital motion within waves by water with depths less than one-half their wavelength.
  • Tsunami, Seiches, and Tides Key Ideas Seiches

    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.
  • Tsunamis in Alaska

    Tsunamis in Alaska

    Tsunami What is a Tsunami? A tsunami is a series of traveling waves in water that are generated by violent vertical displacement of the water surface. Tsunamis travel up to 500 mph across deep water away from their generation zone. Over the deep ocean, there may be very little displacement of the water surface; but since the wave encompasses the depth of the water column, wave amplitude will increase dramatically as it encounters shallow coastal waters. In many cases, a El Niño tsunami wave appears like an endlessly onrushing tide which forces its way around through any obstacle. The image on the left illustrates how the amplitude of a tsunami wave increases as it moves from the deep ocean water to the shallow coast. Over deep water, the wave length is long, and the wave velocity is very fast. By the time the wave reaches the coast, wave length decreases quickly and wave speed slows dramatically. As this takes place, wave height builds up as it prepares to inundate the shore. Why do Tsunamis occur in Alaska? Subduction-zone mega-thrust earthquakes, the most powerful earthquakes in the world, can produce tsunamis through fault boundary rupture, deformation of an overlying plate, and landslides induced by the earthquake (IRIS, 2016). Megathrust earthquakes occur along subduction zones, such as those found along the ring of fire (see image to the right). The ring of fire extends northward along the coast of western North America, then arcs westward along the southern side of the Aleutians, before curving southwest along the coast of Asia.
  • 2018 NOAA Science Report National Oceanic and Atmospheric Administration U.S

    2018 NOAA Science Report National Oceanic and Atmospheric Administration U.S

    2018 NOAA Science Report National Oceanic and Atmospheric Administration U.S. Department of Commerce NOAA Technical Memorandum NOAA Research Council-001 2018 NOAA Science Report Harry Cikanek, Ned Cyr, Ming Ji, Gary Matlock, Steve Thur NOAA Silver Spring, Maryland February 2019 NATIONAL OCEANIC AND NOAA Research Council noaa ATMOSPHERIC ADMINISTRATION 2018 NOAA Science Report Harry Cikanek, Ned Cyr, Ming Ji, Gary Matlock, Steve Thur NOAA Silver Spring, Maryland February 2019 UNITED STATES NATIONAL OCEANIC National Oceanic and DEPARTMENT OF AND ATMOSPHERIC Atmospheric Administration COMMERCE ADMINISTRATION Research Council Wilbur Ross RDML Tim Gallaudet, Ph.D., Craig N. McLean Secretary USN Ret., Acting NOAA NOAA Research Council Chair Administrator Francisco Werner, Ph.D. NOAA Research Council Vice Chair NOTICE This document was prepared as an account of work sponsored by an agency of the United States Government. The views and opinions of the authors expressed herein do not necessarily state or reflect those of the United States Government or any agency or Contractor thereof. Neither the United States Government, nor Contractor, nor any of their employees, make any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, product, or process disclosed, or represents that its use would not infringe privately owned rights. Mention of a commercial company or product does not constitute an endorsement by the National Oceanic and Atmospheric Administration.
  • Experimental Observation of Modulational Instability in Crossing Surface Gravity Wavetrains

    Experimental Observation of Modulational Instability in Crossing Surface Gravity Wavetrains

    fluids Article Experimental Observation of Modulational Instability in Crossing Surface Gravity Wavetrains James N. Steer 1 , Mark L. McAllister 2, Alistair G. L. Borthwick 1 and Ton S. van den Bremer 2,* 1 School of Engineering, The University of Edinburgh, King’s Buildings, Edinburgh EH9 3DW, UK; [email protected] (J.N.S.); [email protected] (A.G.L.B.) 2 Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK; [email protected] * Correspondence: [email protected] Received: 3 April 2019; Accepted: 30 May 2019; Published: 4 June 2019 Abstract: The coupled nonlinear Schrödinger equation (CNLSE) is a wave envelope evolution equation applicable to two crossing, narrow-banded wave systems. Modulational instability (MI), a feature of the nonlinear Schrödinger wave equation, is characterized (to first order) by an exponential growth of sideband components and the formation of distinct wave pulses, often containing extreme waves. Linear stability analysis of the CNLSE shows the effect of crossing angle, q, on MI, and reveals instabilities between 0◦ < q < 35◦, 46◦ < q < 143◦, and 145◦ < q < 180◦. Herein, the modulational stability of crossing wavetrains seeded with symmetrical sidebands is determined experimentally from tests in a circular wave basin. Experiments were carried out at 12 crossing angles between 0◦ ≤ q ≤ 88◦, and strong unidirectional sideband growth was observed. This growth reduced significantly at angles beyond q ≈ 20◦, reaching complete stability at q = 30–40◦. We find satisfactory agreement between numerical predictions (using a time-marching CNLSE solver) and experimental measurements for all crossing angles.
  • Atlantic Hurricane Activity During the Last Millennium

    Atlantic Hurricane Activity During the Last Millennium

    www.nature.com/scientificreports OPEN Atlantic hurricane activity during the last millennium Michael J. Burn1 & Suzanne E. Palmer2 Received: 13 February 2015 Hurricanes are a persistent socio-economic hazard for countries situated in and around the Accepted: 10 July 2015 Main Development Region (MDR) of Atlantic tropical cyclones. Climate-model simulations have Published: 05 August 2015 attributed their interdecadal variability to changes in solar and volcanic activity, Saharan dust flux, anthropogenic greenhouse gas and aerosol emissions and heat transport within the global ocean conveyor belt. However, the attribution of hurricane activity to specific forcing factors is hampered by the short observational record of Atlantic storms. Here, we present the Extended Hurricane Activity (EHA) index, the first empirical reconstruction of Atlantic tropical cyclone activity for the last millennium, derived from a high-resolution lake sediment geochemical record from Jamaica. The EHA correlates significantly with decadal changes in tropical Atlantic sea surface temperatures (SSTs; r = 0.68; 1854–2008), the Accumulated Cyclone Energy index (ACE; r = 0.90; 1851–2010), and two annually-resolved coral-based SST reconstructions (1773–2008) from within the MDR. Our results corroborate evidence for the increasing trend of hurricane activity during the Industrial Era; however, we show that contemporary activity has not exceeded the range of natural climate variability exhibited during the last millennium. The extent to which the climate dynamics of the Main Development Region (MDR) of Atlantic tropical cyclone activity are controlled by natural or anthropogenic climatic forcing factors remains unclear1,2. This uncertainty has arisen because of the reliance on historical meteorological records, which are too short to capture the natural long-term variability of climatic phenomena as well as a lack of understand- ing of the physical link between tropical Atlantic SSTs and tropical cyclone variability3,4.
  • Downloaded 09/27/21 06:58 AM UTC 3328 JOURNAL of the ATMOSPHERIC SCIENCES VOLUME 76 Y 2

    Downloaded 09/27/21 06:58 AM UTC 3328 JOURNAL of the ATMOSPHERIC SCIENCES VOLUME 76 Y 2

    NOVEMBER 2019 S C H L U T O W 3327 Modulational Stability of Nonlinear Saturated Gravity Waves MARK SCHLUTOW Institut fur€ Mathematik, Freie Universitat€ Berlin, Berlin, Germany (Manuscript received 15 March 2019, in final form 13 July 2019) ABSTRACT Stationary gravity waves, such as mountain lee waves, are effectively described by Grimshaw’s dissipative modulation equations even in high altitudes where they become nonlinear due to their large amplitudes. In this theoretical study, a wave-Reynolds number is introduced to characterize general solutions to these modulation equations. This nondimensional number relates the vertical linear group velocity with wave- number, pressure scale height, and kinematic molecular/eddy viscosity. It is demonstrated by analytic and numerical methods that Lindzen-type waves in the saturation region, that is, where the wave-Reynolds number is of order unity, destabilize by transient perturbations. It is proposed that this mechanism may be a generator for secondary waves due to direct wave–mean-flow interaction. By assumption, the primary waves are exactly such that altitudinal amplitude growth and viscous damping are balanced and by that the am- plitude is maximized. Implications of these results on the relation between mean-flow acceleration and wave breaking heights are discussed. 1. Introduction dynamic instabilities that act on the small scale comparable to the wavelength. For instance, Klostermeyer (1991) Atmospheric gravity waves generated in the lee of showed that all inviscid nonlinear Boussinesq waves are mountains extend over scales across which the back- prone to parametric instabilities. The waves do not im- ground may change significantly. The wave field can mediately disappear by the small-scale instabilities, rather persist throughout the layers from the troposphere to the perturbations grow comparably slowly such that the the deep atmosphere, the mesosphere and beyond waves persist in their overall structure over several more (Fritts et al.
  • EARTH SCIENCE ACTIVITY #1 Tsunami in a Bottle

    EARTH SCIENCE ACTIVITY #1 Tsunami in a Bottle

    EARTH SCIENCE ACTIVITY #1 Grades 3 and Up Tsunami in a Bottle This activity is one of several in a basic curriculum designed to increase student knowledge about earthquake science and preparedness. The activities can be done at any time in the weeks leading up to the ShakeOut drill. Each activity can be used in classrooms, museums, and other educational settings. They are not sequence-bound, but when used together they provide an overview of earthquake information for children and students of various ages. All activities can be found at www.shakeout.org/schools/resources/. Please review the content background (page 3) to gain a full understanding of the material conducted in this activity. OBJECTIVE: For students to learn that tsunamis can be caused by earthquakes and to understand the effects of tsunamis on the shoreline MATERIALS/RESOURCES NEEDED: 2-liter plastic soda bottles Small gravel (fish tank gravel) Water source Empty water bottle (16 oz) Overhead projector Transparency of Tsunami Facts “What Do I See?” handout PRIOR KNOWLEDGE: In order to conduct this activity, students need to know how fault slippage can generate earthquakes. ACTIVITY: Set-Up (Time varies) Collect as many 2-liter soda bottles as possible or ask students to bring in bottles for this activity (3 students can share one bottle). Obtain an empty water bottle (about 16 oz). Remove labels from all bottles. Purchase or gather enough small gravel to fit through the mouth of the soda bottles. Students will fill up their soda bottles with gravel to create at least a 2 inch layer on the bottom of the bottle.
  • Modelling of Ocean Waves with the Alber Equation: Application to Non-Parametric Spectra and Generalisation to Crossing Seas

    Modelling of Ocean Waves with the Alber Equation: Application to Non-Parametric Spectra and Generalisation to Crossing Seas

    fluids Article Modelling of Ocean Waves with the Alber Equation: Application to Non-Parametric Spectra and Generalisation to Crossing Seas Agissilaos G. Athanassoulis 1,* and Odin Gramstad 2 1 Department of Mathematics, University of Dundee, Dundee DD1 4HN, UK 2 Hydrodynamics, MetOcean & SRA, Energy Systems, DNV, 1363 Høvik, Norway; [email protected] * Correspondence: [email protected] Abstract: The Alber equation is a phase-averaged second-moment model used to study the statistics of a sea state, which has recently been attracting renewed attention. We extend it in two ways: firstly, we derive a generalized Alber system starting from a system of nonlinear Schrödinger equations, which contains the classical Alber equation as a special case but can also describe crossing seas, i.e., two wavesystems with different wavenumbers crossing. (These can be two completely independent wavenumbers, i.e., in general different directions and different moduli.) We also derive the associated two-dimensional scalar instability condition. This is the first time that a modulation instability condition applicable to crossing seas has been systematically derived for general spectra. Secondly, we use the classical Alber equation and its associated instability condition to quantify how close a given nonparametric spectrum is to being modulationally unstable. We apply this to a dataset of 100 nonparametric spectra provided by the Norwegian Meteorological Institute and find that the Citation: Athanassoulis, A.G.; vast majority of realistic spectra turn out to be stable, but three extreme sea states are found to be Gramstad, O. Modelling of Ocean Waves with the Alber Equation: unstable (out of 20 sea states chosen for their severity).
  • Santa Rosa County Tsunami/Rogue Wave

    Santa Rosa County Tsunami/Rogue Wave

    SANTA ROSA COUNTY TSUNAMI/ROGUE WAVE EVACUATION PLAN Banda Aceh, Indonesia, December 2004, before/after tsunami photos 1 Table of Contents Introduction …………………………………………………………………………………….. 3 Purpose…………………………………………………………………………………………. 3 Definitions………………………………………………………………………………………… 3 Assumptions……………………………………………………………. ……………………….. 4 Participants……………………………………………………………………………………….. 4 Tsunami Characteristics………………………………………………………………………….. 4 Tsunami Warning Procedure…………………………………………………………………….. 6 National Weather Service Tsunami Warning Procedures…………………………………….. 7 Basic Plan………………………………………………………………………………………….. 10 Concept of Operations……………………………………………………………………………. 12 Public Awareness Campaign……………………………………………………………………. 10 Resuming Normal Operations…………………………………………………………………….13 Tsunami Evacuation Warning Notice…………………………………………………………….14 2 INTRODUCTION: Santa Rosa County Emergency Management developed a Santa Rosa County-specific Tsunami/Rogue wave Evacuation Plan. In the event a Tsunami1 threatens Santa Rosa County, the activation of this plan will guide the actions of the responsible agencies in the coordination and evacuation of Navarre Beach residents and visitors from the beach and other threatened areas. The goal of this plan is to provide for the timely evacuation of the Navarre Beach area in the event of a Tsunami Warning. An alternative to evacuating Navarre Beach residents off of the barrier island involves vertical evacuation. Vertical evacuation consists of the evacuation of persons from an entire area, floor, or wing of a building
  • Re-Mapping the 2004 Boxing Day Tsunami Inundation in the Banda Aceh Region with Attention to Probable Sea Level Rise

    Re-Mapping the 2004 Boxing Day Tsunami Inundation in the Banda Aceh Region with Attention to Probable Sea Level Rise

    Re-mapping the 2004 Boxing Day Tsunami Inundation in the Banda Aceh Region with Attention to Probable Sea Level Rise Elizabeth E. Webb Senior Integrative Exercise April 21, 2009 Submitted in partial fulfillment of the requirements for a Bachelor of Arts degree from Carleton College, Northfield, Minnesota. TABLE OF CONTENTS Abstract Introduction …………………………………………………………………… 1 Tectonic Background …………………………………………………………. 2 Geologic Background ……………………………………………………...…. 4 Tsunami Models ……………………………………………………………… 5 Sea Level Rise ………………………………………………………………... 8 Astronomical Tides Subsidence Climate Change Mechanisms Data Collection Models Sea Level Rise in the 20th and 21st Centuries Globally Regionally Data …………………………………………………………………………. 14 Methods ……………………………………………………………………... 16 Results ………………..……………………………………………………… 19 Linear Model Exponential Model Discussion …………………………………………………………………… 21 Conclusion ………………………………………………………………….. 23 Acknowledgements …………………………………………………………. 23 References …………………………………………………………………... 24 Re-mapping the 2004 Boxing Day Tsunami Inundation in the Banda Aceh Region with Attention to Probable Sea Level Rise Elizabeth Webb Senior Integrative Exercise, March 2009 Carleton College Advisors: Mary Savina, Carleton College Susan Sakimoto, University of Notre Dame ABSTRACT The effects of the Great Sumatra-Andaman Earthquake and the resulting tsunami on December 26, 2004 were greatest in the Banda Aceh region of northern Sumatra, where wave heights reached between 9 and 12 meters. Studies of the Sumatra-Andaman fault indicate that
  • Modulational Instability in Linearly Coupled Asymmetric Dual-Core Fibers

    Modulational Instability in Linearly Coupled Asymmetric Dual-Core Fibers

    applied sciences Article Modulational Instability in Linearly Coupled Asymmetric Dual-Core Fibers Arjunan Govindarajan 1,†, Boris A. Malomed 2,3,*, Arumugam Mahalingam 4 and Ambikapathy Uthayakumar 1,* 1 Department of Physics, Presidency College, Chennai 600 005, Tamilnadu, India; [email protected] 2 Department of Physical Electronics, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978, Israel 3 Laboratory of Nonlinear-Optical Informatics, ITMO University, St. Petersburg 197101, Russia 4 Department of Physics, Anna University, Chennai 600 025, Tamilnadu, India; [email protected] * Correspondence: [email protected] (B.A.M.); [email protected] (A.U.) † Current address: Centre for Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirappalli 620 024, Tamilnadu, India. Academic Editor: Christophe Finot Received: 25 April 2017; Accepted: 13 June 2017; Published: 22 June 2017 Abstract: We investigate modulational instability (MI) in asymmetric dual-core nonlinear directional couplers incorporating the effects of the differences in effective mode areas and group velocity dispersions, as well as phase- and group-velocity mismatches. Using coupled-mode equations for this system, we identify MI conditions from the linearization with respect to small perturbations. First, we compare the MI spectra of the asymmetric system and its symmetric counterpart in the case of the anomalous group-velocity dispersion (GVD). In particular, it is demonstrated that the increase of the inter-core linear-coupling coefficient leads to a reduction of the MI gain spectrum in the asymmetric coupler. The analysis is extended for the asymmetric system in the normal-GVD regime, where the coupling induces and controls the MI, as well as for the system with opposite GVD signs in the two cores.