DOCSLIB.ORG

New Concept for Monitoring SO2 Emissions from Tavurvur Volcano in Papua New Guinea

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
New Concept for Monitoring SO2 Emissions from Tavurvur Volcano in Papua New Guinea BACHELOR THESIS 15 CREDITS DEPARTMENT OF GEOPHYSICS New concept for monitoring SO2 emissions from Tavurvur volcano in Papua New Guinea Author: Supervisor: Julia WALLIUS Prof. Olafur GUDMUNDSSON A thesis submitted in fulfillment of the requirements for the degree of Bachelor in Physics December 22, 2017 Sammanfattning Nytt koncept för att övervaka SO2 utsläpp från vulkanen Tavurvur i Papua Nya Guinea Julia Wallius Under en period på 29 dagar under oktober månad 2016 kördes ett dubbelstrålat DOAS instrument med brett synfält på ön Matupit i Papua Nya Guinea. Detta för att mäta svaveldioxidutsläppen från vulkanen Tavurvur, som ligger på Gazelle halvön i provinsen East New Britain. På grund av otillförlitliga inställningar under de första 17 dagarna så utgick de slutgiltliga resultaten från mätningar tagna mellan den 19:e och 30:e oktober med ett två dagars uppehåll under den 25:e och 26:e oktober då instru- mentet användes för att istället erhålla vindhastighetdata. Det genomsnittliga flödet av kg SO2 bestämmdes för denna period till att ligga på 0.27 s med en vindhastighet på m 3.9 s . Användandet av ett dubbelstrålat DOAS instrument med brett synfält rekom- menderas vid Tavurvur när gasutsläppen är låga och vindriktningen är övervägande sydvästlig. En vinkel på 13 grader över horisonten användes för att erhålla refer- ensspektra av himlen för varje skanningsuppsättning men på grund av SO2 spår i dessa spektra så anses denna vinkel vara för liten och att höja denna mellan 5-10 grader för referensspektra rekommenderas för framtida mätningar. Nyckelord: Optisk fjärranalys, DOAS, Vulkanövervakning, SO2-utsläpp Examensarbete C i geofysik, 1GE037, 15 hp, 2017 Handledare: Olafur Gudmundsson Institutionen för geovetenskaper, Uppsala universitet, Villavägen 16, 752 36 Uppsala (www.geo.uu.se) Hela publikationen finns tillgänglig på www.diva-portal.org Abstract New concept for monitoring SO2 emissions from Tavurvur volcano in Papua New Guinea Julia Wallius During a period of 29 consecutive days during the month of October 2016 a dual- beam wide-field-of-view DOAS instrument was deployed at Matupit Island in Papua New Guinea. This was to measure the sulphur dioxide emissions from Tavurvur vol- cano located on the Gazelle Peninsula of the island East New Britain. Due to unreliable settings for the first 17 days the final results used were derived from measurements taken between October 19th and 30th with a two day gap during the 25th and 26th of October when the instrument was used for obtaining wind speed data. The average i kg flux of SO2 was determined for the period to be 0.27 s with a wind speed estimation of m 3.9 s . The use of a dual-beam wide-field-of-view DOAS instrument is recommended at Tavurvur when the degassing levels are low and the wind is predominantly southwest- erly. An angle of 13 degrees above the horizon was used to obtain the sky reference spectrum for each set of scans, but on account of SO2 traces in these spectra this an- gle is considered too low and lifting the sky reference 5-10 degrees is recommended for future measurements. Keywords: Optic remote sensing, DOAS, Volcano monitoring, SO2 emissions Independent Degree Project C in Geophysics, 1GE037, 15 credits, 2017 Supervisor: Olafur Gudmundsson Department of Earth Sciences, Uppsala University, Villavägen 16, SE-752 36 Uppsala (www.geo.uu.se) The whole document is available at www.diva-portal.org ii Acknowledgements This project would not have been possible without the invaluable help from Rabaul Vol- canological Observatory, in particular Kila Mulina and Ima Itikarai. Special thanks also go out to John Bosco and Ezequiel from RVO for their work assembling and installing the instrument on site. And finally, a huge thank you to Bo Galle and Santiago Arel- lano from Chalmers University for allowing me to be a part of their Papua New Guinea field campaign and all the help and support they provided both on site and before de- parture. Funding for this project was provided by a SIDA Minor Field Study grant and DCO-DECADE. iii A note on the text As part of the larger Rabaul caldera Tavurvur in itself is not a volcano but merely a sub-vent. However, for simplification, Tavurvur is referred to as a volcano throughout this thesis. iv Contents Acknowledgements iii List of Abbreviations vii 1 Introduction1 1.1 Rabaul caldera................................1 1.2 Method and purpose of study........................2 2 Background5 2.1 Differential Optical Absorption Spectroscopy................5 2.1.1 Lambert-Beer’s Law.........................6 2.2 DOAS Measurements and Corrections...................7 2.2.1 Fraunhofer spectrum.........................8 2.2.2 Ring effect..............................8 2.2.3 High-pass filtering..........................9 2.2.4 Dark current.............................9 2.2.5 Sky reference.............................9 2.3 Dual-beam wide-field-of-view DOAS....................9 2.4 Elevation angle................................ 11 2.5 Wind speed calculation........................... 12 2.6 Previous DOAS measurements on Tavurvur................ 12 3 Method 13 3.1 Materials and instrument assembling.................... 13 3.2 Configuration and testing of instrument................... 15 3.3 Installation.................................. 15 3.4 Scanner settings and properties...................... 16 3.4.1 Measurement modes........................ 16 Sensitive detection.......................... 16 Average flux............................. 16 3.5 Data evaluation................................ 19 4 Results 21 4.1 Offsets..................................... 21 4.2 SO2 fluxes.................................. 23 v 5 Discussion 25 5.1 Wind direction and speed.......................... 25 5.2 Recommendation............................... 25 6 Conclusions 26 Bibliography 27 vi List of Abbreviations COSPEC Correlation Spectroscopy D Day DB-WFOV Dual-beam wide-field-of-view DCO-DECADE Deep Carbon Observatory, Deep Earth Carbon Degassing DECADE Deep Earth Carbon Degassing DOAS Differential Optical Absorption Spectroscopy GPS Global Positioning System KG Kilogram M Meter NOVAC Network for Observation of Volcanic and Atmospheric Change O3 Ozone PPM Parts Per Million RVO Rabaul Volcanological Observatory S Second SO2 Sulphur dioxide T Ton UV Ultraviolet vii Chapter 1 Introduction For many years, volcanological monitoring has been an important tool used in order to further our understanding of the workings of volcanoes and the degree to which we can accurately predict a coming volcanic eruption (United States Geological Survey 2016). To this end, scientists have long recognized that the surveillance of volcanic gases play an important part, as gases dissolved in magma provide the driving force of volcanic eruptions. The observation of any changes in the release of certain gases from a vol- cano can therefore help forecast volcanic activity and provide insight into the processes behind eruptions (United States Geological Survey 2015). More specifically, the be- havior of magma bodies as they ascent and descent in relation to eruptions can be better understood by conducting high temporal SO2 emission measurements over long time periods (Galle et al., 2010). Together with other geophysical data it is also possi- ble to interpret the relationship between magma ascent and conduit and hydrothermal processes (Olmos et al., 2007) (Sparks, 2003). In fact, the relationship between gas signals and other geophysical measurement methods is conceivably strong, and it is possible that the process of volcanic degassing is responsible for, or at least closely related to, observed ground deformation and seismicity (Oppenheimer and McGonigle, 2004). Volcanoes also contribute to the release of many toxic gases into the atmosphere, which makes them a relevant study in context with the Earth’s climate. During recent years this specific topic has been given more and more attention, as the emission of a wide variety of volatile species, some of which are converted into aerosols during transport in the atmosphere, makes volcanism one of the main climate-forcing agents and a natural volatile source with important impact upon ecosystems at both local and regional scales (Allard et al., 2016). By measuring the gas emissions, evaluating the data and observing any underlying trends, the potential impact of volcanic emissions on the atmosphere and climate can begin to be understood. 1.1 Rabaul caldera Papua New Guinea occupies the eastern half of the island of New Guinea and its offshore islands in Melanesia, placing it in the pacific “Ring of fire” - a name given to the ring of volcanoes around the Pacific Ocean, a result of plate tectonics - which makes it highly prone to disaster. 1 Chapter 1. Introduction At the northeastern end of the province East New Britain lies Rabaul, a small town inside a large caldera known as Rabaul Volcano. For many years Rabaul was consid- ered the most important settlement of the province and served as a popular boating destination for both commercial and recreational purposes (Wikipedia 2017), before the eruptions of the sub-vents Tavurvur and Vulcan in 1994 devastated the town. The present-day shape of the caldera, with a wide opening where the sea forms Blanche Bay to the east, is reckoned to have been formed by a major eruption around 1400 years ago (Volcano Discovery 2017). Besides Tavurvur and Vulcan, other vents along its 14 km length include Turanguna, Rabalanakia, Sulphur Creek, Kombiu and the Beehives. The Rabual Volcanological Observatory (RVO) is a branch
Load more

Recommended publications
  • AGRICULTURAL. SYSTEMS of PAPUA NEW GUINEA Ing Paper No. 14
    AUSTRALIAN AtGENCY for INTERNATIONAL DEVELOPMENT AGRICULTURAL. SYSTEMS OF PAPUA NEW GUINEA ing Paper No. 14 EAST NIEW BRITAIN PROVINCE TEXT SUMMARIES, MAPS, CODE LISTS AND VILLAGE IDENTIFICATION R.M. Bourke, B.J. Allen, R.L. Hide, D. Fritsch, T. Geob, R. Grau, 5. Heai, P. Hobsb21wn, G. Ling, S. Lyon and M. Poienou REVISED and REPRINTED 2002 THE AUSTRALIAN NATIONAL UNIVERSITY PAPUA NEW GUINEA DEPARTMENT OF AGRI LTURE AND LIVESTOCK UNIVERSITY OF PAPUA NEW GUINEA Agricultural Systems of Papua New Guinea Working Papers I. Bourke, R.M., B.J. Allen, P. Hobsbawn and J. Conway (1998) Papua New Guinea: Text Summaries (two volumes). 2. Allen, BJ., R.L. Hide. R.M. Bourke, D. Fritsch, R. Grau, E. Lowes, T. Nen, E. Nirsie, J. Risimeri and M. Woruba (2002) East Sepik. Province: Text Summaries, Maps, Code Lists and Village Identification. 3. Bourke, R.M., BJ. Allen, R.L. Hide, D. Fritsch, R. Grau, E. Lowes, T. Nen, E. Nirsie, J. Risimeri and M. Woruba (2002) West Sepik Province: Text Summaries, Maps, Code Lists and Village Identification. 4. Allen, BJ., R.L. Hide, R.M. Bourke, W. Akus, D. Fritsch, R. Grau, G. Ling and E. Lowes (2002) Western Province: Text Summaries, Maps, Code Lists and Village Identification. 5. Hide, R.L., R.M. Bourke, BJ. Allen, N. Fereday, D. Fritsch, R. Grau, E. Lowes and M. Woruba (2002) Gulf Province: Text Summaries, Maps, Code Lists and Village Identification. 6. Hide, R.L., R.M. Bourke, B.J. Allen, T. Betitis, D. Fritsch, R. Grau. L. Kurika, E. Lowes, D.K. Mitchell, S.S.
    [Show full text]
  • 13. Eruptions at Rabaul: 1994–1999
    13. Eruptions at Rabaul: 1994–1999 Many of our old folk (our patuana) knew that an eruption was imminent. The strength of the earthquakes told them that an eruption was only a matter of days or hours away … . But the government authorities had not said anything about an eruption … . The Volcanological Observatory, as we have always been told, has some of the most modern and sophisticated monitoring equipment which can predict an eruption to the minute. How come these machines have not said anything about an imminent eruption? Derol Ereman, a Boisen High School student from Matupit Island (quoted by Neumann, 1995, pp. 2–3). First Three Weeks Independence Day celebrations for the 19th national birthday of Papua New Guinea were interrupted by earthquake activity over the weekend in Rabaul beginning at 2.50–2.51 am on Sunday 18 September 1994. Two earthquakes about 40 seconds apart — one near Tavurvur the other near Vulcan — were felt strongly throughout the harbour area. Aftershocks and ground shaking continued, particularly in the Vulcan area. Rabaul Volcanological Observatory (RVO) volcanologists suspected, for about 12 hours, that the earthquake activity represented another ‘seismic swarm’, similar to many of those experienced in Rabaul during the 1970s and 1980s. The ground shaking continued and, by Sunday afternoon, villagers near Tavurvur on Matupit Island had begun a spontaneous evacuation into Rabaul town, encouraged by older people who recalled the 1937 volcanic eruption. Hundreds of other Matupits, however, remained on their threatened island.1 The number of people moving along the road grew, fed by other nearby communities, and by evening thousands of evacuees had gathered at oodlit Queen Elizabeth Park, an evacuation assembly point prescribed in the Rabaul Disaster Plan.
    [Show full text]
  • Emulating Volcanic Ash Fall for Multi‑Scale Analysis:Development of The
    MANILA Record 2014/36 | GeoCat 81611 Emulating volcanic ash fall for multi-scale analysis: Development of the VAPAHR tool and application to the Asia-Pacific region for the United Nations Global Assessment Report 2015 Bear-Crozier, A. N.1, Miller, V.1, Newey, V.1, Horspool, N.1 and Weber, R.1 APPLYING GEOSCIENCE TO AUSTRALIA’S MOST IMPORTANT CHALLENGES www.ga.gov.au Emulating volcanic ash fall for multi-scale analysis: Development of the VAPAHR tool and application to the Asia- Pacific region for the United Nations Global Assessment Report 2015 GEOSCIENCE AUSTRALIA RECORD 2014/36 Bear-Crozier, A. N.1, Miller, V.1, Newey, V.1, Horspool, N.1 and Weber, R.1 1. Geoscience Australia Department of Industry Minister for Industry: The Hon Ian Macfarlane MP Parliamentary Secretary: The Hon Bob Baldwin MP Secretary: Ms Glenys Beauchamp PSM Geoscience Australia Chief Executive Officer: Dr Chris Pigram This paper is published with the permission of the CEO, Geoscience Australia © Commonwealth of Australia (Geoscience Australia) 2014 With the exception of the Commonwealth Coat of Arms and where otherwise noted, all material in this publication is provided under a Creative Commons Attribution 3.0 Australia Licence. (http://www.creativecommons.org/licenses/by/3.0/au/deed.en) Geoscience Australia has tried to make the information in this product as accurate as possible. However, it does not guarantee that the information is totally accurate or complete. Therefore, you should not solely rely on this information when making a commercial decision. Geoscience Australia is committed to providing web accessible content wherever possible.
    [Show full text]
  • Global Volcanic Earthquake Swarm Database 1979-1989
    U- S- Department of the Interior U. S. Geological Survey GLOBAL VOLCANIC EARTHQUAKE SWARM DATABASE 1979-1989 by John P. Benoit1 '2 and Stephen R. McNutt1 '2 Open-File Report 96-69 This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards (or with the North American Stratigraphic Code). Any use of trade, product, of firm names is for the descriptive purposes only and does not imply endorsement by the U.S. Government. 1 Geophysical Institute at the University of Alaska Fairbanks 903 Koyukuk Dr. P.O. Box 757320 Fairbanks, Alaska 99775-7320 2 Alaska Volcano Observatory 1996 CONTENTS DEVELOPMENT AND DESCRIPTION OF THE GLOBAL VOLCANIC EARTHQUAKE SWARM DATABASE...................................................................................................^^ INTRODUCTION .......................................................................................................................................................A DATABASE STRUCTURE AND D£5c/?/pr/o^...................................................................................................................5 Volcano Table ....................................................................................................................................................6 Earthquake Swarm Table....................................................................................................................................6 Eruption Table ...................................................................................................................................................7
    [Show full text]
  • An Investigation of International Volcano Monitoring Techniques
    AN INVESTIGATION OF INTERNATIONAL VOLCANO MONITORING TECHNIQUES TO PROVIDE AN EVIDENCE BASE FOR FUTURE SUPPORT OF THE RABAUL VOLCANO OBSERVATORY BY THE AUSTRALIAN GOVERNMENT Amy L Parker – Curtin University 0 <Insert Report Title> COPYRIGHT NOTICE This document, ‘An investigation of international of volcano monitoring techniques: to provide an evidence base for future support of the Rabaul Volcano Observatory by the Australian Government’ 2018 is licensed under the Creative Commons Attribution 4.0 Licence, unless otherwise indicated. Please give attribution to: © Commonwealth of Australia 2018 We also request that you observe and retain any notices that may accompany this material as part of the attribution. Notice Identifying Other Material and/or Rights in this Publication: The author of this document has taken steps to both identify third-party material and secure permission for its reproduction and reuse. However, please note that where these third-party materials are not licensed under a Creative Commons licence, or similar terms of use, you should obtain permission from the rights holder to reuse their material beyond the ways you are permitted to use them under the Copyright Act 1968. Further Information For further information about the copyright in this document, please contact: Intellectual Property and Copyright Manager Geoscience Australia GPO Box 378 CANBERRA ACT 2601 Phone: +61 2 6249 9567 or email: [email protected] Bibliographic reference: Parker, A. 2018. An investigation of international volcano monitoring techniques: to provide an evidence base for future support of the Rabaul Volcano Observatory by the Australian Government. FrontierSI technical report for the Australian Government. Corresponding author: Amy Parker – [email protected] 1 Table of Contents EXECUTIVE SUMMARY…………………………………………………………………………………………………………….4 1.
    [Show full text]
  • Papua New Guinea
    PAPUA NEW GUINEA EMERGENCY PREPAREDNESS OPERATIONAL LOGISTICS CONTINGENCY PLAN PART 1 – RISK PROFILE & DRM GLOBAL LOGISTICS CLUSTER – WFP FEBRUARY – MARCH 2011 1 | P a g e A. Summary A. SUMMARY 2 B. CONTEXT 3 A. INTRODUCTION 3 B. BACKGROUND INFORMATION 3 COORDINATION 4 EMERGENCY PREPAREDNESS AT PROVINCIAL LEVEL 4 C. TYPES OF HAZARDS IN PNG 5 DEFINITION 5 TYPES OF DISASTERS 5 CLASSIFICATION OF DISASTERS 5 DISASTER PROBABILITY 6 D. TYPOLOGY OF HAZARDS 7 A. EARTHQUAKES 7 B. TSUNAMIS 8 C. LANDSLIDE/LAND MOVEMENT 10 D. VOLCANIC ERUPTION 11 RVO APPROVED ALERT WARNING SYSTEM 14 E. FLOODS 14 F. DROUGHTS 15 TYPES OF DROUGHTS 16 G. OUTBREAKS OF COMMUNICABLE DISEASES 17 CHOLERA 17 E. PNG DISASTERS RISK PROFILE 19 A. RECENT DISASTERS 21 F. DISASTER RISK MANAGEMENT FRAMEWORK 23 A. THE NATIONAL DM AGENCIES 23 B. DRM AT THE SUB-NATIONAL LEVEL 24 INSTITUTIONAL ARRANGEMENTS AT THE PROVINCIAL LEVEL 24 2 | P a g e B. Context a. Introduction Situated on the Pacific Ring of Fire, Papua New Guinea (PNG) is facing regular natural disasters. Papua New Guinea is prone to earthquakes, volcanic eruptions, tsunamis, cyclones, river and coastal flooding, landslides and drought. It is ranked 54th among countries most exposed to multiple hazards based on land area, according to the World Bank’s Natural Disaster Hotspot study. Large parts of the country are extremely isolated. Most parts of the Highlands were not accessed until the 1930s and many settlements are still inaccessible except by very difficult overland routes or by air. The capital city is still not connected by road to most of the country and the range of communication, including radio, is extremely limited, increasing the inhabitants’ vulnerability.1 The Operational Logistics Contingency Plan (OLCP) sets out agreed and approved policies in relation to all aspects of humanitarian emergency logistics.
    [Show full text]
  • 205 Itikarai Et Al
    Earthquake Engineering in Australia, Canberra 24-26 November 2006 Volcano-tectonic earthquakes and magma reservoirs; their influences on volcanic eruptions in Rabaul caldera Ima Itikarai, Brian Kennett and Cvetan Sinadinovski Australian National University Abstract Since seismic monitoring began in the late 1960s the seismicity in Rabaul caldera has been marked by intra-caldera high frequency volcano-tectonic earthquakes. The hypocentral distribution of these earthquakes defines an outward-dipping elliptical ring- fault in shallow depths. Before the 1994 eruption other prominent seismicity includes a swarm of earthquakes that occurred in May 1992 away from the caldera in a northeasterly direction. After the eruption the intra-caldera seismicity decreased significantly. The majority of the locatable events have been located on the southern section of the ring-fault. These events have been overshadowed by a group of earthquakes that occurred northeast of the caldera. Observations between the ongoing eruptions at Tavurvur and the periodic episodes of northeasterly earthquakes between 1995 and 2005 show interesting correlations. Notable episodes of northeasterly earthquakes have been followed by intensified or renewed eruptive activity. The lead-time between earthquakes and either one of the types of eruptive activity is between few and several months. We speculate that the northeast earthquakes mark episodes of intrusions of a second magma source into the caldera magma reservoir allowing magma mixing to occur, hence resulting in the ongoing eruption at Tavurvur. The tomographic results suggest up to three possible magma reservoirs. The proximity of the northeast earthquakes to the north-northeasterly low velocity anomaly and other information suggests this anomaly is a magma reservoir and is the source of magma injected into the caldera reservoir.
    [Show full text]
  • Fire Mountains of the Islands a History of Volcanic Eruptions and Disaster Management in Papua New Guinea and the Solomon Islands
    Fire Mountains of the Islands A History of Volcanic Eruptions and Disaster Management in Papua New Guinea and the Solomon Islands Fire Mountains of the Islands A History of Volcanic Eruptions and Disaster Management in Papua New Guinea and the Solomon Islands R. Wally Johnson Published by ANU E Press The Australian National University Canberra ACT 0200, Australia Email: [email protected] This title is also available online at http://epress.anu.edu.au National Library of Australia Cataloguing-in-Publication entry Author: Johnson, R. W. (Robert Wallace) Title: Fire mountains of the islands [electronic resource] : a history of volcanic eruptions and disaster management in Papua New Guinea and the Solomon Islands / R. Wally Johnson. ISBN: 9781922144225 (pbk.) 9781922144232 (eBook) Notes: Includes bibliographical references and index. Subjects: Volcanic eruptions--Papua New Guinea. Volcanic eruptions--Solomon Islands. Emergency management--Papua New Guinea. Emergency management--Solomon Islands. Dewey Number: 363.3495095 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying or otherwise, without the prior permission of the publisher. Cover image: John Siune. ‘Dispela helekopta kisim Praim Minista bilong PNG igo lukim volkenu pairap long Rabaul’. 1996. 85 x 60 cm. Acrylic on paper mounted on board. R.W. Johnson collection. Intellectual property rights are held by the artist. Cover design and layout by ANU E Press Printed by Grin Press This edition © 2013 ANU E Press Contents Tables ix Illustrations xi Foreword xvii Acknowledgements and Sources xxi Volcano Names and Totals xxiii 1.
    [Show full text]
  • World Bank Document
    Building Capacity by Rebuilding Community Assets: Learning from the Gazelle Restoration Authority (GRA) Experience Background Public Disclosure Authorized The purpose of this review is to bring a more locally-relevant perspective to the World Bank‟s understanding of dynamics of statebuilding, development, and governance in Papua New Guinea (PNG) by exploring the specific lessons from the experience of the post-disaster reconstruction program led by the Gazelle Restoration Authority (GRA) in East New Britain province, after a catastrophic dual volcanic eruption in 1994. Three audiences exist for this review: those interested in more effective approaches to public works and service delivery in PNG; specialists in post-disaster reconstruction; and World Bank staff seeking ways to contribute to institutional and state effectiveness through project implementation choices. Given these diverse audiences, specific lessons will be offered at the end, for each group. The GRA is generally considered – both by PNG stakeholders and in the wider development community – as an effective institution that produced quality results, and its success is all the Public Disclosure Authorized more remarkable given the difficulties usually encountered in implementing major public work programs in PNG. Most observers emphasize the pre-existing strength and quality of the East New Britain Provincial Administration (ENBPA) – also widely viewed as an exceptionally capable and effective state institution – and elements of the Tolai culture, dominant in ENB, described as fostering a collaborative, pragmatic, and dedicated style of working across public and private sectors. While the Implementation Completion Report for the World Bank-financed project implemented by GRA acknowledges those two elements, it also highlights a range of other enabling factors that are less unique to the ENB context – and potentially more useful in considering these three questions: 1.
    [Show full text]
  • 7. Eruptions During the Pacific War and Postwar Recovery: 1941–1950
    7. Eruptions during the Pacific War and Postwar Recovery: 1941–1950 It was a most awe inspiring sight to see this great mass of smoke, a greyish orange and purple colour just billowing overheard [sic] and sort of rolling over itself and accompanied by the sound of the roar of hundreds of mighty furnaces. Dennis Taylor (1943) Fisher and Renewed Activity from Tavurvur Concerns expressed in early 1941 about future volcanic activity at Rabaul were to a large extent set aside by the greater anxiety of a likely war in the Pacic. The Second World War had broken out in Europe in September 1939, and Japan in 1941 was expanding militarily in the western Pacic and eastern and south- east Asian regions. Nevertheless, a small but vulnerable Australian garrison, Lark Force, was dispatched to Rabaul in March–April 1941.1 It was made up largely of soldiers of the 2/22nd Battalion of the 23rd Brigade, 8th Division, 2nd Australian Imperial Force. The battalion was supplemented by smaller units, one of them the New Guinea Volunteer Ries which was made up of white residents of Rabaul, including volcanologist N.H. Fisher. Consideration was given by the Australian Government to strengthening Rabaul and its magnicent caldera harbour as a major military base in view of the Japanese threat, but this required the resources of the United States, which had not yet entered the war. Tavurvur and Vulcan volcanoes had not been active since 1937. Fisher, however, had been noticing geothermal changes on parts of Tavurvur since August 1940, and a series of tectonic earthquakes had been taking place in the region — including a particularly powerful one just 30 kilometres west of Rabaul on 14 January 1941— which Fisher related to the increased volcanic unrest.2 Vigorous gas emissions were evident in growing fumarolic areas on Tavurvur and temperatures by April 1941 were in excess of 300 ºC.
    [Show full text]
  • Robertson RM, Kilburn
    Earth and Planetary Science Letters 438 (2016) 86–94 Contents lists available at ScienceDirect Earth and Planetary Science Letters www.elsevier.com/locate/epsl Deformation regime and long-term precursors to eruption at large calderas: Rabaul, Papua New Guinea ∗ Robert M. Robertson, Christopher R.J. Kilburn UCL Hazard Centre, Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK a r t i c l e i n f o a b s t r a c t Article history: Eruptions at large calderas are normally preceded by variable rates of unrest that continue for decades or Received 6 July 2015 more. A classic example is the 1994 eruption of Rabaul caldera, in Papua New Guinea, which began after Received in revised form 26 December 2015 23 years of surface uplift and volcano-tectonic (VT) seismicity at rates that changed unevenly with time Accepted 4 January 2016 by an order of magnitude. Although the VT event rate and uplift rate peaked in 1983–1985, eruptions Available online xxxx only began a decade later and followed just 27 hours of anomalous changes in precursory signal. Here Editor: T.A. Mather we argue that the entire 23 years of unrest belongs to a single sequence of damage accumulation in the Keywords: crust and that, in 1991–1992, the crust’s response to applied stress changed from quasi-elastic (elastic large caldera deformation with minor fault movement) to inelastic (deformation predominantly by fault movement Rabaul alone). The change in behaviour yields limiting trends in the variation of VT event rate with deformation eruption precursors and can be quantified with a mean-field model for an elastic crust that contains a dispersed population eruption forecasts of small faults.
    [Show full text]