THERMAL REMOTE SENSING OF ACTIVE VOLCANOES

Transcription

1 THERMAL REMOTE SENSING OF ACTIVE VOLCANOES A User s Manual Active volcanoes emit heat through lava flows and erupting vents. Remote measurements of heat emission from such active features can provide insights into the physical processes governing volcanic activity. Development of thermal remote sensing, and improved dataprocessing techniques, have enabled operational use of infrared instruments to perform volcano radiometry and to quantify the thermal flux from eruptions and volcanic systems, leading to better detection and measurement of volcanic activity. This book encapsulates over 100 years of research developments, forming a comprehensive manual for measurements of Earth surface temperatures and heat fluxes. With a particular focus on volcanic hot spots, the book explores methodologies and principles used with satellite, radiometer and thermal-camera data. It presents traditional applications using satellite- and ground-based sensors as well as modern applications that have evolved for use with hand-held thermal cameras, and is fully illustrated with case studies, data bases and worked examples. Chapter topics include techniques for thermal mixture modeling and heat flux derivation, and methods for data collection, mapping, and time series generation. Appendices covering specific sensors and their deployment, plus an extensive reference list, provide the reader with a rigorous background. Online supplements present additional specific notes on areas of sensor application and data processing. This book is an invaluable resource for academic researchers and graduate students in the fields of thermal remote sensing, volcanology, geophysics and planetary studies. It is also of interest to anyone involved in the fields of Earth and space science. andrew harris is a professor at Université Blaise Pascal (Clermont Ferrand, France) and holder of the Chaire d Excellence for the Auvergne region. He is a member of the Remote Sensing Society, IAVCEI and AGU, and has worked with a variety of ground- and satellitebased thermal data sets, having deployed experimental equipment at active volcanoes in Africa, Europe, Central America, South America and Hawaii. Dr. Harris has published over 130 publications in international scientific journals dedicated to thermal remote sensing and volcanology. His work has been recognized by several awards, including IAVCEI s Wager medal (2004) and the University of Hawaii Regents Medals for both excellence in research (2003) and teaching (2005).

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3 THERMAL REMOTE SENSING OF ACTIVE VOLCANOES A User s Manual ANDREW HARRIS Université de Clermont-Ferrand II (Université Blaise Pascal)

4 cambridge university press Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, São Paulo, Delhi, Mexico City Cambridge University Press The Edinburgh Building, Cambridge CB2 8RU, UK Published in the United States of America by Cambridge University Press, New York Information on this title: / This publication is in copyright. Subject to statutory exception and to the provisions of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. First published 2013 Printed and bound in the United Kingdom by the MPG Books Group A catalog record for this publication is available from the British Library Library of Congress Cataloging in Publication data Harris, Andrew, 1967 Thermal Remote Sensing of Active Volcanoes : A User s Manual /. p. cm. ISBN (hardback) 1. Volcanic ash, tuff, lava, etc. Temperature Remote sensing. 2. Volcanological research. 3. Terrestrial radiation Measurement. 4. Volcanic activity prediction. I. Title. QE H dc ISBN Hardback Additional resources for this publication at /radiometry Cambridge University Press has no responsibility for the persistence or accuracy of URLs for external or third-party internet websites referred to in this publication, and does not guarantee that any content on such websites is, or will remain, accurate or appropriate.

5 Contents Acknowledgments page ix 0 Introduction: Background, motivation and essential definitions Remote sensing of terrestrial volcanic hot spots: a brief history Thermal remote sensing: What it is and what we have Reviews to date and the value of thermal remote sensing Thermal remote sensing of volcanic hot spots on other planets Aim and use of this book Structure and content of this book Supporting material and companion texts Waveband definitions A final note: hot spots and thermal anomalies what do we mean? 16 Part I Introduction and underlying principles 19 1 History of thermal remote sensing of active volcanism Nimbus, Surtsey and subsequent work A history of satellite infrared sensors A history of the discipline Ground-based and airborne sensors 54 2 Thermal remote sensing of active volcanism: principles The Planck Function, Wein s Displacement Law and Stefan Boltzmann Emissivity Atmospheric effects Brightness temperature and surface temperature: how to obtain surface temperature Summation 111 v

6 vi Contents 3 Satellite orbits and sensor resolution Orbits and temporal resolution The sensor: the basic acquisition system Spatial resolution Spectral resolution and response Selection of an appropriate sensor 150 Part II Space-based volcano radiometry The mixed pixel, the dual-band technique, heat loss and volume flux The problem of the thermally mixed pixel The dual-band method Three-component solutions Heat flux Mass and volume Hot spot detection Detection by eye Detection: physical basis Automated hot spot detection algorithms How can we detect eruption termination? Cool anomalies Operational volcano hot spot detection systems Mapping, classification, time series and profiles Hot spot maps Hot spot classification Types of time series Time series generation Case studies Trends and smoothing Spatial profiles Use of multiple platform data for validation Inventories: the current status of satellite remote sensing 410 Part III Ground-based volcano radiometry and thermography Broad-band radiometers I: instrumentation and application Detector types Broad-band radiometers: capabilities and operation Review of radiometer measurements of volcanic phenomena Permanent deployment Broad-band radiometers II: data collection and analysis principles Lava flows and lakes 453

7 Contents vii 8.2 Vents and fumarole fields Explosive eruptions Thermal waveforms associated with bomb-dominated emission Slope of the waveform and velocity Response time and slew rate Radiometers versus imagers Broad-band thermal imaging cameras Thermal camera: general texts The hand-held thermal camera Thermal camera applications in volcanology: history and classification Measurement principles Deployment principles: making the measurement Methodologies Methodologies II: temperature measurements Methodologies III: dimensional and volume/mass measurements Surveillance and monitoring End note 625 Appendix A Collation and summary of satellite-volcano radiometry: a literature data base 627 Appendix B Estimation of solar zenith angle and contribution of reflected radiation to at-satellite radiance 639 Appendix C TM-class sensors 646 Appendix D AVHRR-class sensors 651 Appendix E GOES-class sensors 661 Appendix F Scan and satellite location geometry 666 Appendix G Automated volcano hot spot detection: worked example 669 Appendix H Optical pyrometers 680 Appendix I Thermal camera options 684 References 688 Index 717 Electronic supplements available at /radiometry ES 1 Detection capabilities of thermal sensors ES 2 Calibration ES 3 Surface temperature retrieval ES 4 Notes on application of emissivity, atmospheric and surface reflection corrections ES 5 The dual-band method: A history of its application to volcanic hot spots ES 6 The dual-band method: worked examples

8 viii Contents ES 7 Conversion from spectral radiance to lava area, heat flux and discharge rate ES 8 Fire detection algorithms, ES 9 Fixed threshold algorithms used for volcano hot spot detection ES 10 Image sharpening and density slicing: An example using an AVHRR image ES 11 Etna eruption: MODIS-derived time series data Color plate section is found between pages 344 and 345

9 Acknowledgments This book was initially an effort led by the thermal remote sensing group of the Hawaii Institute of Planetology and Geophysics (HIGP) at the University of Hawaii. It resulted from a proposal, made to Cambridge University Press in 2005, by Robert Wright, and also involved Luke Flynn and Peter Mouginis-Mark. Figure drafting was completed by Lucia Gurioli, supported by funding provided by the Hawaii Space Grant Consortium. Andrew Harris wrote this book while a faculty member at HIGP and, from 2009 onwards, at the Laboratoire Magmas et Volcans (Université Blaise Pascal). The author is most grateful to Thomas and Daniel Harris for giving up valuable playing time to allow book completion, as well as for making useful suggestions. I am also extremely grateful for the time, effort and careful edits made by each of the chapter reviewers, these being: Dave Rothery (Chapters 0 and 1), Martin Wooster (Chapters 2 and 3), Clive Oppenheimer, Laszlo Keszthelyi and Steve Baloga (Chapter 4), Tania Ganci (Chapter 5), Mike Ramsey (Chapter 6), Harry Pinkerton (Chapter 7), Mike James (Chapter 8), and Letizia Spampinato and Matthew Patrick (Chapter 9). Finally, I thank Fran Van Wyk de Vries for helping with a thorough final check of the delivered text. This work was supported by the Région Auvergne (Chaire d Excellence) and is ClerVolc Center of Excellence contribution no. 41. ix