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On the Use of the Coda of Seismic Noise Autocorrelations to Compute H/V Spectral Ratios Flomin Tchawe Nziaha, Berenice Froment, Michel Campillo, Ludovic Margerin
On the use of the coda of seismic noise autocorrelations to compute H/V spectral ratios Flomin Tchawe Nziaha, Berenice Froment, Michel Campillo, Ludovic Margerin To cite this version: Flomin Tchawe Nziaha, Berenice Froment, Michel Campillo, Ludovic Margerin. On the use of the coda of seismic noise autocorrelations to compute H/V spectral ratios. Geophysical Journal International, Oxford University Press (OUP), 2019, 220 (3), pp.1956-1964. 10.1093/gji/ggz553. hal-02635754 HAL Id: hal-02635754 https://hal.archives-ouvertes.fr/hal-02635754 Submitted on 27 May 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Geophysical Journal International Geophys. J. Int. (2020) 220, 1956-1964 doi: 10.1093/gji/ggz553 Advance Access publication 2019 December 06 GJI Seismology On the use of the coda of seismic noise autocorrélations to compute H/V spectral ratios F.N. Tchawe,1 B. Froment,1 M. Campillo2 and L. Margerin3 1 Institut de Radioprotection et de Surete Nucléaire, Fontenay-aux-Roses, France. E-mail: [email protected] 2Institut des Sciences de la Terre, Universite Grenoble Alpes, CNRS, IRD, Grenoble, France 3Institut de Recherche en Astrophysique et Planetologie, Observatoire Midi-Pyrenees, Universite Paul Sabatier, CNRS, Toulouse, France Downloaded Accepted 2019 December 4. -
Geography) 2018
IASbaba’s 60 Days Plan – Day 46 (Geography) 2018 Q.1) Consider the following statements. 1. A mid-oceanic ridge is composed of two chains of mountains separated by a large depression. 2. Mid-oceanic ridges are formed at convergent boundary of two plates. Which of the above statements is/are correct? a) 1 only b) 2 only c) Both 1 and 2 d) None Q.1) Solution (a) A mid-oceanic ridge is composed of two chains of mountains separated by a large depression. The mountain ranges can have peaks as high as 2,500 m and some even reach above the ocean’s surface. Running for a total length of 75,000 km, these ridges form the largest mountain systems on earth. These ridges are either broad, like a plateau, gently sloping or in the form of steep- sided narrow mountains. These oceanic ridge systems are of tectonic origin formed at divergent plate boundaries and provide evidence in support of the theory of Plate Tectonics. Do you know? A land bridge, in biogeography, is an isthmus or wider land connection between otherwise separate areas, over which animals and plants are able to cross and colonise new lands. A land bridge can be created by marine regression, in which sea levels fall, exposing shallow, previously submerged sections of continental shelf; or when new land is created by plate tectonics; or occasionally when the sea floor rises due to post-glacial rebound after an ice age. THINK! Straits Q.2) ‘Insular shelf’ means a) A continental shelf allocated to landlocked countries. -
Nori Nakata, Lucia Gualtieri and Andreas Fichtner
SEISMIC AMBIENT NOISE E D I T E D B Y Nori Nakata, Lucia Gualtieri and Andreas Fichtner Cambridge University Press 978-1-108-41708-2 — Seismic Ambient Noise Edited by Nori Nakata , Lucia Gualtieri , Andreas Fichtner Frontmatter More Information SEISMIC AMBIENT NOISE The seismic ambient field allows us to study interactions between the atmosphere, the oceans, and the solid Earth. The theoretical understanding of seismic ambi- ent noise has improved substantially over recent decades, and the number of its applications has increased dramatically. With chapters written by eminent scien- tists from the field, this book covers a range of topics including ambient noise observations, generation models of their physical origins, numerical modeling, and processing methods. The later chapters focus on applications in imaging and monitoring the internal structure of the Earth, including interferometry for time- dependent imaging and tomography. This volume thus provides a comprehensive overview of this cutting-edge discipline for graduate students studying geophysics and for scientists working in seismology and other imaging sciences. NORI NAKATA is a principal research scientist in geophysics at the Mas- sachusetts Institute of Technology. He received the Mendenhall Prize from the Colorado School of Mines in 2013 and the Young Scientist Award from the Seismo- logical Society of Japan in 2017. His research interests include crustal and global seismology, exploration geophysics, volcanology, and civil engineering. LUCIA GUALTIERI is a postdoctoral research associate at Princeton Univer- sity, mainly interested in studying the coupling between the solid Earth and the other Earth systems, and in using seismic signals to image the Earth’s structure. -
Impulse Response of Civil Structures from Ambient Noise Analysis by German A
Bulletin of the Seismological Society of America, Vol. 100, No. 5A, pp. 2322–2328, October 2010, doi: 10.1785/0120090285 Ⓔ Short Note Impulse Response of Civil Structures from Ambient Noise Analysis by German A. Prieto, Jesse F. Lawrence, Angela I. Chung, and Monica D. Kohler Abstract Increased monitoring of civil structures for response to earthquake motions is fundamental to reducing seismic risk. Seismic monitoring is difficult because typically only a few useful, intermediate to large earthquakes occur per decade near instrumented structures. Here, we demonstrate that the impulse response function (IRF) of a multistory building can be generated from ambient noise. Estimated shear- wave velocity, attenuation values, and resonance frequencies from the IRF agree with previous estimates for the instrumented University of California, Los Angeles, Factor building. The accuracy of the approach is demonstrated by predicting the Factor build- ing’s response to an M 4.2 earthquake. The methodology described here allows for rapid, noninvasive determination of structural parameters from the IRFs within days and could be used for state-of-health monitoring of civil structures (buildings, bridges, etc.) before and/or after major earthquakes. Online Material: Movies of IRF and earthquake shaking. Introduction Determining a building’s response to earthquake an elastic medium from one point to another; traditionally, it motions for risk assessment is a primary goal of seismolo- is the response recorded at a receiver when a unit impulse is gists and structural engineers alike (e.g., Cader, 1936a,b; applied at a source location at time 0. Çelebi et al., 1993; Clinton et al., 2006; Snieder and Safak, In many studies using ambient vibrations from engineer- 2006; Chopra, 2007; Kohler et al., 2007). -
Passive Seismic Interferometry in the Real World: Application with Microseismic and Traffic Noise
Passive seismic interferometry in the real world: Application with microseismic and traffic noise By Yang Zhao A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Engineering - Civil and Environmental Engineering in the Graduate Division of the University of California, Berkeley Committee in charge: Professor James W. Rector III, Chair Professor Steven D. Glaser Professor Doug Dreger Fall 2013 Passive seismic interferometry in the real world: Application with microseismic and traffic noise © 2013 by Yang Zhao Abstract Passive seismic interferometry in the real world: Application with microseismic and traffic noise by Yang Zhao Doctor of Philosophy in Civil and Environmental Engineering University of California, Berkeley Professor James Rector III, Chair The past decade witnessed rapid development of the theory of passive seismic interferometry followed by numerous applications of interferometric approaches in seismic exploration and exploitation. Developments conclusively demonstrates that a stack of cross- correlations of traces recorded by two receivers over sources appropriately distributed in three-dimensional heterogeneous earth can retrieve a signal that would be observed at one receiver if another acted as a source of seismic waves. The main objective of this dissertation was to review the mathematical proof of passive seismic interferometry, and to develop innovative applications using microseismicity induced by hydraulic fracturing and near-surface void characterization. We began this dissertation with the definitions and mathematical proof of Green’s function representation, together with the description of the physical mechanisms of passive seismic interferometry. Selected computational methods of passive seismic interferometry are also included. The first application was to extract body waves and perform anisotropy analysis from passive downhole microseismic noise acquired in hydrocarbon-bearing reservoirs. -
Ambient Vibration Modal Analysis of Rock
https://doi.org/10.5194/esurf-2021-36 Preprint. Discussion started: 6 May 2021 c Author(s) 2021. CC BY 4.0 License. Short Communication: Ambient Vibration Modal Analysis of Rock Arches using Enhanced Frequency Domain Decomposition and Covariance-driven Stochastic Subspace Identification Mauro Häusler1, Paul R. Geimer2, Riley Finnegan2, Donat Fäh1, Jeffrey R. Moore2 5 1Swiss Seismological Service, ETH Zurich, Zurich, 8092, Switzerland 2Department of Geology and Geophysics, University of Utah, Salt Lake City, 84112, USA Correspondence to: Mauro Häusler ([email protected]) Abstract Natural rock arches are rare and beautiful geologic landforms with important cultural value. As such, their 10 management requires periodic assessment of structural integrity to understand environmental and anthropogenic influences on arch stability. Measurements of passive seismic vibrations represent a rapid and non-invasive technique to describe the dynamic properties of natural arches, including resonant frequencies, modal damping ratios, and mode shapes, which can be monitored over time for structural health assessment. However, commonly applied spectral analysis tools are often limited in their ability to resolve characteristics of closely spaced or complex higher-order modes. Therefore, we investigate two 15 algorithms well-established in the field of civil engineering through application to a set of natural arches previously characterized using conventional seismological techniques. Results from enhanced frequency domain decomposition and parametric covariance-driven stochastic subspace identification modal analyses showed generally good agreement with spectral peak-picking and frequency-dependent polarization analyses. However, we show that these advanced techniques offer the capability to resolve closely spaced modes and provide stable damping estimates. In addition, due to preservation of phase 20 information, enhanced frequency domain decomposition allows for direct and convenient three-dimensional visualization of mode shapes. -
Tutorial on Seismic Interferometry: Part 1 — Basic Principles and Applications
GEOPHYSICS, VOL.75, NO. 5 ͑SEPTEMBER-OCTOBER 2010͒; P.75A195–75A209, 15 FIGS. 10.1190/1.3457445 Tutorial on seismic interferometry: Part 1 — Basic principles and applications Kees Wapenaar1, Deyan Draganov1, Roel Snieder2, Xander Campman3, and Arie Verdel3 ABSTRACT retrieval of seismic surface-wave responses from ambient noise and the subsequent tomographic determination of the surface- Seismic interferometry involves the crosscorrelation of re- wave velocity distribution of the subsurface. Seismic interferom- sponses at different receivers to obtain the Green’s function be- etry is not restricted to retrieving direct waves between receivers. tween these receivers. For the simple situation of an impulsive In a classic paper, Claerbout shows that the autocorrelation of the plane wave propagating along the x-axis, the crosscorrelation of transmission response of a layered medium gives the plane-wave the responses at two receivers along the x-axis gives the Green’s reflection response of that medium. This is essentially 1D reflect- function of the direct wave between these receivers. When the ed-wave interferometry. Similarly, the crosscorrelation of the source function of the plane wave is a transient ͑as in exploration transmission responses, observed at two receivers, of an arbitrary seismology͒ or a noise signal ͑as in passive seismology͒, then the inhomogeneous medium gives the 3D reflection response of that crosscorrelation gives the Green’s function, convolved with the medium. One of the main applications of reflected-wave interfer- autocorrelation of the source function. Direct-wave interferome- ometry is retrieving the seismic reflection response from ambient try also holds for 2D and 3D situations, assuming the receivers noise and imaging of the reflectors in the subsurface. -
Low-Frequency Ambient Noise Autocorrelations: Waveforms and Normal Modes by M
SRL Early Edition ○E Low-Frequency Ambient Noise Autocorrelations: Waveforms and Normal Modes by M. Schimmel, E. Stutzmann, and S. Ventosa ABSTRACT Seismic interferometry by ambient noise autocorrelations is free oscillations of the Earth. The corresponding frequencies a special case of Green’s function retrieval for single-station are functionals of the Earth structure, shape, and movement. analysis. Although high-frequency noise autocorrelations are The free oscillations are built up by the interference of propa- now used to extract the reflectivity beneath seismic stations, gating waves, which therefore relate to the modes by mode low-frequency autocorrelations are hardly applied. Here, we superposition (e.g., Woodhouse and Deuss, 2015). At the present the observation of the Earth orbiting surface waves lowermost frequencies, these are mostly the Earth orbiting sur- from low-frequency noise autocorrelations which are used to face waves. These waves are excited by strong earthquakes or extract normal-mode frequencies for the Hum. The perfor- strong ambient noise sources. mances of the classical and phase autocorrelations are analyzed The low-frequency noise sources cause continuous free using seismic data from GEOSCOPE station TAM in Algeria. background oscillations, called Hum, which are observed dur- Both approaches are independent and perform differently for ing the absence of strong earthquakes on land (Kobayashi and data with large amplitude variability. We show that the phase Nishida, 1998; Nawa et al., 1998; Suda et al., 1998; Tanimoto autocorrelation can robustly extract Rayleigh waves and nor- et al., 1998) and since recently at the ocean bottom (Deen et al., mal modes because it is not biased by large amplitude signals 2017). -
Draft IEE: Viet Nam: Water Sector Investment Program
Initial Environmental Examination Project Number: 41456-033 March 2011 MFF 0054-VIE: Water Sector Investment Program – Tranche 2 This initial environmental examination is a document of the borrower. The views expressed herein do not necessarily represent those of ADB’s Board of Directors, Management, or staff, and may be preliminary in nature. Your attention is directed to the “terms of use” section of this website. In preparing any country program or strategy, financing any project, or by making any designation of or reference to a particular territory or geographic area in this document, the Asian Development Bank does not intend to make any judgments as to the legal or other status of any territory or area. Rehabilitating and Upgrading Project of Haiphong Water Supply System – Stage II: Final Report - Draft Supplementary Appendix 19-a Initial Environmental Examination Construction of Kim Son Water Supply System AECOM Asia Company Ltd. Supplementary Appendix 19-a Rehabilitating and Upgrading Project of Haiphong Water Supply System – Stage II: Final Report - Draft Table of Contents Abbreviations, Weights and Measures, Currency Equivalent iii I. EXECUTIVE SUMMARY 1 A. Purpose of the Report 1 B. Rehabilitating & Upgrading Project of the Hai Phong Water Supply System - 1 Stage II C. Construction of Kim Son Water System 2 D. Summary of Impacts and Mitigation Measures 3 E. Information Disclosure, Consultation and Participation 4 F. Grievance Redress Mechanism 4 G. Environmental Management Plan 5 H. Conclusion 6 II. POLICY, LEGAL & ADMINISTRATIVE FRAMEWORK 7 A. Policy and Legal Framework 7 B. Assessment and Approval Requirements 8 III. DESCRIPTION OF THE SUBPROJECT 8 A. -
Full Scale Dynamic Response of a Rc Building Under Weak Seismic Motions Using Earthquake Recordings, Ambient Vibrations and Modelling
FULL SCALE DYNAMIC RESPONSE OF A RC BUILDING UNDER WEAK SEISMIC MOTIONS USING EARTHQUAKE RECORDINGS, AMBIENT VIBRATIONS AND MODELLING Clotaire MICHEL1, Philippe GUEGUEN2 Saber EL AREM3, Jacky MAZARS3, Panagiotis KOTRONIS3 1 Applied Computing and Mechanics Laboratory (IMAC), Ecole Polytechnique Fédérale de Lausanne, Switzerland 2 LGIT, University Joseph Fourier, CNRS, LCPC, France 3 3S-R, University Joseph Fourier, CNRS, INPG, France submitted for Earthquake Engineering and Structural Dynamics Laboratoire de Géophysique Interne et Tectonophysique (LGIT) Université de Grenoble 1381 rue de la Piscine 38041 Grenoble Cedex 9 FRANCE Corresponding author P. Guéguen LGIT BP 53 38041 Grenoble cedex 9 France [email protected] 1/20 Abstract In countries with a moderate seismic hazard, the classical methods developed for strong motion prone countries to estimate the seismic behaviour and subsequent vulnerability of existing build- ings are often inadequate and not financially realistic. The main goals of this paper are to show how the modal analysis can contribute to the understanding of the seismic building response and the good relevancy of a modal model based on ambient vibrations for estimating the structural deformation under moderate earthquakes. We describe the application of an enhanced modal analysis technique (Frequency Domain Decomposition) to process ambient vibration recordings taken at the Grenoble City Hall building (France). The frequencies of ambient vibrations are compared with those of weak earthquakes recorded by the French permanent accelerometric net- work (RAP) that was installed to monitor the building. The frequency variations of the building under moderate earthquakes are shown to be slight (~2%) and therefore ambient vibration fre- quencies are relevant over the elastic domain of the building. -
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ANNALS OF GEOPHYSICS, 63, 2, DM215, 2020; doi:10.4401/ag-7857 The Earth Lab 5s (ETL3D/5s) seismic sensor. Design and test Gioacchino Fertitta1, Antonio Costanza1, Giuseppe D’anna*,1, Domenico Patanè2 (1) Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Nazionale Terremoti, Rome, Italy (2) Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo, Sezione di Catania, Italy Article history: received July 12, 2018; accepted November 13, 2019 Abstract This work presents a new low cost and low power consumption wide-band (5s) three-component seismic sensor, named ETL3D/5s. The sensor is suitable for seismic regional monitoring (local and regional earthquakes), HVSR measurements, seismic microzonation studies and Structural Health Monitoring (SHM) of civil structures. ETL3D/5s includes a set of three 4.5 Hz geophones and an electronic circuit that increases the geophone’s natural period. The sensor exhibits a period of 5 s and a power consumption as low as 75 mW. Changes in ambient temperature have a small effect on the frequency response because a temperature compensation system is also implemented. A small and sturdy cylindrical housing contains the electronic boards and geophones. The housing design was supported by a modal FEM analysis, in order not to affect the frequency response. The chosen materials and parts guarantee protection against atmospheric agents and watertightness (IP68 degree). The sensor noise model, partially confirmed by a field test, predicts a power spectral density of 10 (nm/s)/√Hz at 1Hz. Keywords: Seismic sensor; Lippman method; Low cost seismology; Induced seismicity; Building monitoring; Urban Seismic Observatory; FEM modal analysis. 1. Introduction Seismic sensors are classified according to what form of ground motion they measure, namely ground velocity (geophones) or ground acceleration (accelerometers). -
Financial Management of Earthquake Risk
Financial Management of Earthquake Risk Please cite this publication as: OECD (2018), Financial Management of Earthquake Risk, www.oecd.org/finance/Financial-Management-of-Earthquake-Risk.htm. This work is published under the responsibility of the Secretary-General of the OECD. The opinions expressed and arguments employed herein do not necessarily reflect the official views of the OECD or of the governments of its member countries or those of the European Union. This document and any map included herein are without prejudice to the status of or sovereignty over any territory, to the delimitation of international frontiers and boundaries and to the name of any territory, city or area. © OECD 2018 FOREWORD │ 5 Foreword Disasters present a broad range of human, social, financial, economic and environmental impacts, with potentially long-lasting, multi-generational effects. The financial management of these impacts is a key challenge for individuals, businesses and governments in developed and developing countries. The Financial Management of Earthquake Risk applies the lessons from the OECD’s analysis of disaster risk financing practices and the application of its guidance to the specific case of earthquakes. The report provides an overview of the approaches that economies facing various levels of earthquake risk and economic development have taken to managing the financial impacts of earthquakes. The OECD supports the development of strategies and the implementation of effective approaches for the financial management of natural and man-made disaster risks under the guidance of the OECD High-Level Advisory Board on Financial Management of Catastrophic Risks and the OECD Insurance and Private Pensions Committee.