DOCSLIB.ORG

Earthquakes Increase Flood Hazard in Christchurch, New Zealand

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Earthquakes Increase Flood Hazard in Christchurch, New Zealand MARCH/APRIL | VOL. 25, 3–4 2015 NO. A PUBLICATION OF THE GEOLOGICAL SOCIETY OF AMERICA® The sinking city: Earthquakes increase flood hazard in Christchurch, New Zealand MARCH/APRIL 2015 | VOLUME 25, NUMBER 3–4 Featured Article GSA TODAY (ISSN 1052-5173 USPS 0456-530) prints news and information for more than 26,000 GSA member readers and subscribing libraries, with 11 monthly issues (March/ April is a combined issue). GSA TODAY is published by The SCIENCE ARTICLE: Geological Society of America® Inc. (GSA) with offices at 3300 Penrose Place, Boulder, Colorado, USA, and a mail- 4 The sinking city: Earthquakes increase ing address of P.O. Box 9140, Boulder, CO 80301-9140, USA. flood hazard in Christchurch, New Zealand GSA provides this and other forums for the presentation of diverse opinions and positions by scientists worldwide, Matthew W. Hughes et al. regardless of race, citizenship, gender, sexual orientation, Cover: Aerial view of the suburbs of Bexley and New religion, or political viewpoint. Opinions presented in this Brighton in eastern Christchurch, New Zealand, looking publication do not reflect official positions of the Society. east to the Pacific Ocean on the day after the 22 February © 2015 The Geological Society of America Inc. All rights 2011 M 6.2 Christchurch earthquake. Expulsion of sand reserved. Copyright not claimed on content prepared W wholly by U.S. government employees within the scope of and groundwater during earthquake-induced liquefaction their employment. Individual scientists are hereby granted and related surface subsidence of >30 cm caused flooding in permission, without fees or request to GSA, to use a single this area and increased long-term flood hazard. Residential figure, table, and/or brief paragraph of text in subsequent dwellings built in Bexley until 2005 (shown in foreground) work and to make/print unlimited copies of items in GSA TODAY for noncommercial use in classrooms to further are being demolished, and the land has been purchased and education and science. In addition, an author has the right “Red Zoned” by the New Zealand central government. to use his or her article or a portion of the article in a thesis Photo by M.C. Quigley. See related article, p. 4–10. or dissertation without requesting permission from GSA, provided the bibliographic citation and the GSA copyright credit line are given on the appropriate pages. For any other use, contact [email protected]. Subscriptions: GSA members: Contact GSA Sales & Service, +1-888-443-4472; +1-303-357-1000 option 3; gsaservice@ geosociety.org for information and/or to place a claim for non-receipt or damaged copies. Nonmembers and institutions: GSA News GSA TODAY is US$88/yr; to subscribe, or for claims for non-receipt and damaged copies, contact gsaservice@ geosociety.org. Claims are honored for one year; please 11 Elections: GSA Officers and Councilors allow sufficient delivery time for overseas copies. Peri- odicals postage paid at Boulder, Colorado, USA, and at 12 How to Successfully Apply to GSA Education & Outreach Programs additional mailing offices. Postmaster: Send address changes to GSA Sales & Service, P.O. Box 9140, Boulder, CO 80301-9140. 13 On To the Future (OTF) 2015 GSA TODAY STAFF 13 GeoCorpsTM America Fall/Winter 2015–2016 Interum Executive Director and Publisher: Judith Totman Parrish 14 Get into the Field: GSA/ExxonMobil Awards Science Editors: Steven Whitmeyer, James Madison University Dept. of Geology & Environmental Science, 800 S. Main Street, MSC 6903, Harrisonburg, VA 22807, 16 Second Announcement: GSA Cordilleran Section Meeting USA, [email protected]; Gerald Dickens, Rice University School of Earth Science, MS-126, 6100 Main Street, Houston, Texas 77005, USA, [email protected]. 18 Education & Outreach Programs: 2015 Section Meetings Managing Editor: K.E.A. “Kea” Giles, [email protected], [email protected] 19 Call for Nominations: GSA Division Awards Graphics Production: Margo McGrew 20 Call for Nominations: John C. Frye Environmental Geology Award Advertising (classifieds & display): Ann Crawford, +1-800-472-1988 ext. 1053; +1-303-357-1053; Fax: +1-303- 357-1070; [email protected]; acrawford@ 20 New and Revised GSA Position Statements geosociety.org GSA Online: www.geosociety.org 21 Call for GSA Committee Service GSA TODAY: www.geosociety.org/gsatoday/ Printed in the USA using pure soy inks. 22 Penrose Conference Announcement 24 2014–2015 Congressional Science Fellow Report: A Geoscientist on “The Hill” 26 Geoscience Jobs & Opportunities 27 GSA Today : The Choice is Yours 29 GSA Foundation Update: Education & Outreach Career and Mentor Programs The sinking city: Earthquakes increase flood hazard in Christchurch, New Zealand Matthew W. Hughes, Dept. of Civil & Natural Resources Engineering, (e.g., sea-level rise, storm surges, tsunamis) and terrestrial hazards University of Canterbury, Private Bag 4800, Ilam, Christchurch, New (e.g., surface subsidence and compaction, flooding, erosion, sedi- Zealand; Mark C. Quigley, Dept. of Geological Sciences, University of ment supply changes, groundwater table changes) induced by Canterbury, Private Bag 4800, Ilam, Christchurch, New Zealand; natural and/or anthropogenic processes (Syvitski et al., 2009; Sjoerd van Ballegooy, Bruce L. Deam, Tonkin & Taylor Ltd, PO Box Nicholls and Cazenave, 2010). Coastal population growth and 5271, Wellesley Street, Auckland 1141, New Zealand; Brendon A. concentration, economic development, and urbanization are Bradley, Dept. of Civil & Natural Resources Engineering, University of expected to greatly increase exposure and loss to the impacts of rela- Canterbury, Private Bag 4800, Ilam, Christchurch, New Zealand; tive sea-level rise (Nicholls and Cazenave, 2010; IPCC, 2014) and Deirdre E. Hart, Dept. of Geography, University of Canterbury, Private coastal flooding (Hanson et al., 2011; Hallegatte et al., 2013) through Bag 4800, Ilam, Christchurch, New Zealand; and Richard Measures, the next century, defining one of society’s greatest challenges. National Institute of Water & Atmospheric Research (NIWA), PO Box Geospatial data, such as satellite-based synthetic aperture radar and 8602, Christchurch, New Zealand airborne light detection and ranging (LiDAR), are increasingly being used to measure surface subsidence and delineate areas prone ABSTRACT to flood and sea-level rise hazards (Dixon et al., 2006; Wang et al., 2012; Webster et al., 2006), thereby assisting land-use planning Airborne light detection and ranging (LiDAR) data were and management decisions (Brock and Purkis, 2009). acquired over the coastal city of Christchurch, New Zealand, prior Great (MW ≥ 8.5) earthquakes on subduction zones may cause to and throughout the 2010 to 2011 Canterbury Earthquake abrupt and dramatic elevation changes to coastal environments. Sequence. Differencing of pre- and post-earthquake LiDAR data The 1964 MW 9.0 Alaska earthquake caused tidal marshes and reveals land surface and waterway deformation due to seismic wetlands to subside up to 2 m (Shennan and Hamilton, 2006); the shaking and tectonic displacements above blind faults. Shaking 2005 MW 8.7 Nias earthquake caused up to 3 m in coastal uplift caused floodplain subsidence in excess of 0.5 to 1 m along tidal proximal to the trench and 1 m of more distal coastal subsidence stretches of the two main urban rivers, greatly enhancing the (Briggs et al., 2006); and the 2011 MW 9.0 Tohoku earthquake spatial extent and severity of inundation hazards posed by caused subsidence up to 1.2 m along the Pacific Coast of north- 100-year floods, storm surges, and sea-level rise. Additional eastern Japan (Geospatial Information Authority of Japan, 2011, shaking effects included river channel narrowing and shallowing, cited in IPCC, 2014). However, the influence of moderate magni- due primarily to liquefaction, and lateral spreading and sedimen- tude (i.e., MW 6–7) earthquakes, which can occur in both inter- tation, which further increased flood hazard. Differential tectonic plate and intraplate settings, on coastal flood and sea-level movement and associated narrowing of downstream river chan- hazards is not well characterized and not typically included in nels decreased channel gradients and volumetric capacities and studies that assess the future vulnerability of coastal populations increased upstream flood hazards. Flood mitigation along the (McGranahan et al., 2007). large regional Waimakariri River north of Christchurch may have, In this paper, we summarize differential vertical and horizontal paradoxically, increased the long-term flood hazard in the city by ground movements in Christchurch, New Zealand, using airborne halting long-term aggradation of the alluvial plain upon which LiDAR survey data captured prior to, during, and after the 2010 to Christchurch is situated. Our findings highlight the potential for 2011 Canterbury Earthquake Sequence (CES). Differential LiDAR moderate magnitude (MW 6–7) earthquakes to cause major topo- applications in earthquake studies have been used to map defor- graphic changes that influence flood hazard in coastal settings. mation along fault zones (e.g., Duffy et al., 2013; Oskin et al., INTRODUCTION 2012); however, this is the first differential LiDAR study showing the cumulative surface effects of earthquake shaking and faulting 2015 Approximately 10% of the world’s population inhabits low- on an urban environment. Here we show that earthquakes lying (≤10 m above sea level) coastal areas, and most of this popu- sourced from blind and/or
Load more

Recommended publications
  • Novel Habitats, Rare Plants and Root Traits
    Lincoln University Digital Thesis Copyright Statement The digital copy of this thesis is protected by the Copyright Act 1994 (New Zealand). This thesis may be consulted by you, provided you comply with the provisions of the Act and the following conditions of use: you will use the copy only for the purposes of research or private study you will recognise the author's right to be identified as the author of the thesis and due acknowledgement will be made to the author where appropriate you will obtain the author's permission before publishing any material from the thesis. Novel Habitats, Rare Plants and Roots Traits A thesis submitted in partial fulfilment of the requirements for the Degree of Master of Applied Science at Lincoln University by Paula Ann Greer Lincoln University 2017 Abstract of a thesis submitted in partial fulfilment of the requirements for the Degree of Master of Applied Science. Abstract Novel habitats, rare plants and root traits. by Paula Ann Greer The loss of native plant species through habitat loss has been happening in NZ since the arrival of humans. This is especially true in Canterbury where less than 1% of the lowland plains are believed to be covered in remnant native vegetation. Rural land uses are changing and farm intensification is creating novel habitats, including farm irrigation earth dams. Dam engineers prefer not to have plants growing on dams. Earth dams are consented for 100 years, they could be used to support threatened native plants. Within the farm conversion of the present study dams have created an average of 1.7 hectares of ‘new land’ on their outside slope alone, which is the area of my research.
    [Show full text]
  • Earthquakes Increase Flood Hazard in Christchurch, New Zealand
    The sinking city: Earthquakes increase flood hazard in Christchurch, New Zealand Matthew W. Hughes, Dept. of Civil & Natural Resources Engineering, (e.g., sea-level rise, storm surges, tsunamis) and terrestrial hazards University of Canterbury, Private Bag 4800, Ilam, Christchurch, New (e.g., surface subsidence and compaction, flooding, erosion, sedi- Zealand; Mark C. Quigley, Dept. of Geological Sciences, University of ment supply changes, groundwater table changes) induced by Canterbury, Private Bag 4800, Ilam, Christchurch, New Zealand; natural and/or anthropogenic processes (Syvitski et al., 2009; Sjoerd van Ballegooy, Bruce L. Deam, Tonkin & Taylor Ltd, PO Box Nicholls and Cazenave, 2010). Coastal population growth and 5271, Wellesley Street, Auckland 1141, New Zealand; Brendon A. concentration, economic development, and urbanization are Bradley, Dept. of Civil & Natural Resources Engineering, University of expected to greatly increase exposure and loss to the impacts of rela- Canterbury, Private Bag 4800, Ilam, Christchurch, New Zealand; tive sea-level rise (Nicholls and Cazenave, 2010; IPCC, 2014) and Deirdre E. Hart, Dept. of Geography, University of Canterbury, Private coastal flooding (Hanson et al., 2011; Hallegatte et al., 2013) through Bag 4800, Ilam, Christchurch, New Zealand; and Richard Measures, the next century, defining one of society’s greatest challenges. National Institute of Water & Atmospheric Research (NIWA), PO Box Geospatial data, such as satellite-based synthetic aperture radar and 8602, Christchurch, New Zealand airborne light detection and ranging (LiDAR), are increasingly being used to measure surface subsidence and delineate areas prone ABSTRACT to flood and sea-level rise hazards (Dixon et al., 2006; Wang et al., 2012; Webster et al., 2006), thereby assisting land-use planning Airborne light detection and ranging (LiDAR) data were and management decisions (Brock and Purkis, 2009).
    [Show full text]
  • Physical Modelling of a High Energy Coastal Lake Outflow, Canterbury, New Zealand
    Ocean Engineering 109 (2015) 181–191 Contents lists available at ScienceDirect Ocean Engineering journal homepage: www.elsevier.com/locate/oceaneng Physical modelling of a high energy coastal lake outflow, Canterbury, New Zealand Crile Doscher a,n, Timothy R.H. Davies b a Faculty of Environment, Society and Design Lincoln University, PO Box 85084 Lincoln, 7647 Canterbury, New Zealand b Department of Geological Sciences University of Canterbury, Christchurch, New Zealand article info abstract Article history: A 1:50 scale laboratory physical model was constructed to simulate canal outflows from Wairewa/Lake Received 4 December 2014 Forsyth, Canterbury, New Zealand, in order to assess the propensity for canal blockage due to beach Accepted 19 August 2015 sediment transport. A terrestrial survey, depth soundings and side scan sonar surveys were carried out to establish baseline topographic data. These data were used to derive a high-resolution digital elevation Keywords: model (DEM) of the area. Profiles derived from the DEM were used to cut metal guides to represent Physical modelling beach topography. These were placed in the model tank and a beach was shaped of fine, silica sand to Longshore drift represent the area of the canal opening. Canal outflows were simulated using flow through a polystyrene Coastal processes channel with a rectangular cross-section. A thin-plate wave generator was built for simulating waves. Sediment transport The model was initially designed to simulate sediment transport by longshore drift from south-westerly swells but was later adapted to also simulate south-south-easterly swells. Testing was carried out simulating the base conditions with and without the existing groyne configuration.
    [Show full text]
  • Significant Coastal Lagoon Systems in the South Island, New Zealand
    Significant coastal lagoon systems in the South Island, New Zealand Coastal processes and lagoon mouth closure SCIENCE FOR CONSERVATION 146 R.M. Kirk and G.A. Lauder Published by Department of Conservation P.O. Box 10-420 Wellington, New Zealand Science for Conservation presents the results of investigations by DOC staff, and by contracted science providers outside the Department of Conservation. Publications in this series are internally and externally peer reviewed. Publication was approved by the Manager, Science & Research Unit, Science Technology and Information Services, Department of Conservation, Wellington. © April 2000, Department of Conservation ISSN 11732946 ISBN 0478219474 Cataloguing-in-Publication data Kirk, R. M. Significant coastal lagoon systems in the South Island, New Zealand : coastal processes and lagoon mouth closure / R.M. Kirk and G.A. Lauder. Wellington, N.Z. :Dept. of Conservation, 2000. 1 v. ; 30 cm. (Science for conservation, 1173-2946 ; 146.) Includes bibliographical references. ISBN 0478219474 1. LagoonsNew ZealandSouth Island. I. Lauder, G. A. II. Title. Series: Science for conservation (Wellington, N.Z.) ; 146. CONTENTS Abstract 5 1. Introduction 6 2. What is a lagoon? 8 2.1 Distinguishing coastal lagoons from estuaries 8 2.2 Definition of types of coastal lagoon 9 2.3 Distribution of coastal lagoons 10 3. Two types of coastal lagoon, South Island, New Zealand 11 3.1 River mouth lagoonshapua 11 3.2 Coastal lakesWaituna-type lagoons 15 3.2.1 Coastal geomorphic character and development 16 3.2.2 Wairau Lagoons 18 3.2.3 Waihora/Lake Ellesmere 18 3.2.4 Waituna Lagoon, Southland 24 3.3 Conclusions 27 4.
    [Show full text]
  • Possibilities and Problems for Nature Conservation in a Closely Settled Area
    MOLLOY: PROBLEMS FOR NATURE CONSERVATION IN A CLOSELY SETTI.ED AREA POSSIBILITIES AND PROBLEMS FOR NATURE CONSERVATION IN A CLOSELY SETTLED AREA Botany Division, Department of Scientific and Industrial Re,lcarch, Christchurch SUMMARY: The distribution of parks and reserves in the Canterbury Land District is outlined, and attention is drawn to the predominance of forest and Ir.oun.tainvegetation within the present network of nature conservation. Other natural communities in the land district are then described, and their Dotential as ecological or scientific reserves is reviewed. In this paper, emphasis is placed on some of the lesser-known communities that still survive in the closely settled environment of the Canterbury Plains. The problems associated with the acquisition and maintenance of reserves are briefly discussed. EXISTING PARKS AND RESERVES Scenic and allied reserves in the Canterbury Land District are concentrated on Banks Peninsula and in the foothills, front ranges and intermontane areas of the Southern Alps. In addition, there are two National Parks (Mount Cook and Arthurs Pass), the new Craigieburn State Forcst Park and Peel Forest Park (also listed here as Scenic Re- serve No. 45), all in mountain districts (Figs. I Arlhu.~ Pass and 2 and accompanying legend). {Nat;onal Pa.k Most of these parks and reserves concern forest communities and associated scrub and grass]and of sparsely populated upland areas. Of the 56 scenic Cra;giebu.n ., and allied reserves, 51 include various forest com- Stale fa.est Pa.k munities, and of these more than half occur on Banks Peninsula. The distribution of parks and Peel Fo.est MtCaok National Pa.k FIGURES I and 2.
    [Show full text]
  • A Review of Archaeological Site Records for the Canterbury Region
    SCIENCE & RESEARCH SERIES NO.45 A REVIEW OF ARCHAEOLOGICAL SITE RECORDS FOR THE CANTERBURY REGION by Aidan J. Challis Published by Head Office, Department of Conservation, P O Box 10-420, Wellington, New Zealand ISSN 0113-3713 ISBN 0-478-01370-1 © April 1992, Department of Conservation National Library of New Zealand Cataloguing-in-Publication data Challis, Aidan J. (Aidan John), 1948- A review of archaeological site records for the Canterbury Region / by Aidan J. Challis. Wellington, N.Z. : Head Office, Dept. of Conservation, c1992. 1 v. (Science & research series, 0113-3713 ; no. 45) Includes bibliographical references. ISBN 0-478-01370-1 1. Historic sites--New Zealand--Canterbury Region— Conservation and restoration. 2. Excavations (Archaeology)— New Zealand--Canterbury Region. 3. Maori (New Zealand people)--New Zealand--Canterbury Region--Antiquities. 4. Canterbury Region (N.Z.)--Antiquities. I. New Zealand. Dept. of Conservation. II. Title. III. Series: Science & research series ; no. 45. 363.6909937 Keywords: Canterbury, archaeology, site recording, site distribution, site destruction, archaeological strategy. CONTENTS ABSTRACT 1 1.THE PROGRESS OF SITE RECORDING 1 2.THE PATTERN OF RESULTS 2 3.THE LIMITATIONS OF LOCATION DATA 6 4.THE SURVIVAL OF THE EVIDENCE 8 5.RECORDED SITES ON PROTECTED LAND 10 6.RECOMMENDATIONS 11 6.1Procedural recommendations 12 6.1.1General strategy 12 6.1.2Land held or managed by DOC 12 6.1.3Private land 13 6.1.4Records 13 6.2Priorities for site recording 13 6.2.1Programmes which should begin as soon as possible 13 6.2.2Programmes which should begin within 3 to 5 years 13 6.2.3Other areas where inventory should be encouraged and assisted 14 6.2.4Other research which should be encouraged 14 7.ACKNOWLEDGEMENTS 14 8.REFERENCES 14 APPENDIX 1 Recorded archaeological sites possibly on Canterbury conservation land units 18 A REVIEW OF ARCHAEOLOGICAL SITE RECORDS FOR THE CANTERBURY REGION By Aidan J.
    [Show full text]
  • Canterbury Protection Strategy
    CANTERBURY LAND PROTECTION STRATEGY A REPORT TO THE NATURE HERITAGE FUND COMMITTEE M.A. HARDING CANTERBURY LAND PROTECTION STRATEGY Published by the Nature Heritage Fund PO Box 10-420 Wellington June 2009 Hard Copy ISBN: 978-0-478-14626-4 PDF ISBN: 978-0-478-14627-1 CD-ROM ISBN: 978-0-478-14630-1 CONTENTS 1.0 Introduction ........................................................................................ 1 2.0 Method............................................................................................... 2 3.0 Original Vegetation of Canterbury..................................................... 4 4.0 The Indigenous Vegetation of each Ecological District..................... 8 5.0 Analysis of Representativeness........................................................ 93 6.0 Criteria for Assessing Protection Proposals................................... 103 7.0 Land Protection Strategy................................................................ 108 8.0 Species Cited by Common Name in Text ...................................... 109 9.0 References Cited in Text................................................................ 111 Appendix 1 Plant Communities by Ecological District............................ 118 The Nature Heritage Fund was established (as the Forest Heritage Fund) in June 1990 following the release of Government’s Indigenous Forest Policy. The objective of this policy is to “ maintain or enhance, in perpetuity, the current area of indigenous forest, either by protection, sustainable management or reafforestation
    [Show full text]
  • Late Quaternary Stratigraphy and Sedimentation of the Canterbury Continental Shelf, New Zealand
    ISSN 0083-7903, 89 (Print) ISSN 2538-1016; 89 (Online) Late Quaternary Stratigraphy and Sedimentation.. of the Canterbury Continental Shelf, New Zealand by R. H. HERZER New Zealand Oceanographic Institute Memoir 89 1981 NEW ZEALAND DEPARTMENT OF SCIENTIFIC AND INDUSTRIAL RESEARCH Late Quaternary Stratigraphy and Sedimentation of the Canterbury Continental Shelf, New Zealand by R. H. HERZER Geology Department, Victoria University of Wellington, Private Bag, Wellington New Zealand Oceanographic Institute Memoir 89 1981 This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-nd/3.0/ ISSN 0083-7903 Received for publication: March 1980 © Crown Copyright 1981 This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-nd/3.0/ CONTENTS Page LIST OF FIGURES 5 LIST OF TABLES 5 ABSTRACT 7 INTRODUCTION 8 BATHYMETRY 9 Methods 9 Geomorphic Zones of the Continental Shelf 11 Zone A 11 ZoneB 11 ZoneC 11 ZoneD 11 ZoneE 16 SEDIMENTSZoneF 16 16 Sampling 16 Analytical Methods 16 Selection of Significant Tex.turalParameters 20 Sediment Map 26 Gravel 26 Sand 28 Mud 28 Distribution of Modes ... 28 Lithic Gravel (Mode I) Distribution 28 Shell GravelDistribution 31 Concretions 31 Sand (Modes II, III, and IV) Distribution 31 Distinction of Sand Modes ... 31 Distribution of Modes III and IV 31 Some Surface Features of the Sediment 34 Origin of the Sediments 34 Provenance of the Gravel 34 Provenance of the Sands 38 The Fauna .
    [Show full text]
  • Environmental and Sea-Level Changes on Banks Peninsula (Canterbury, New Zealand) Through Three Glaciation±Interglaciation Cycles
    ELSEVIER Palaeogeography, Palaeoclimatology, Palaeoecology 152 (1999) 101±127 Environmental and sea-level changes on Banks Peninsula (Canterbury, New Zealand) through three glaciation±interglaciation cycles James Shulmeister a,Ł, Jane M. Soons b,GlennW.Bergerc, Margaret Harper a, Sarah Holt a, Neville Moar d, John A. Carter a a School of Earth Sciences, Victoria University, P.O. Box 600, Wellington, New Zealand b Department of Geography, University of Canterbury, Private Bag 4800, Christchurch, New Zealand c Quaternary Sciences Centre, Desert Research Institute, Reno, NE, USA d Landcare Research, P.O. Box 69, Lincoln, New Zealand Received 4 November 1997; accepted 7 January 1999 Abstract A greater than 200 ka record of marine transgressions and regressions is recorded from a 75 m core from Banks Peninsula, Canterbury, New Zealand. This record comprises thick suites of muddy sediments attributed to back barrier, lake and lagoonal environments alternating with thin soil and loess complexes. These deposits have been dated using radio- carbon and thermoluminescence (TL) techniques supported by proxy data (diatoms, phytoliths, pollen and sedimentology). The aqueous deposits are attributed to three interglacials and an interstadial (Marine Isotope Stages 1, 5a, 5c, 6, and 7). The loesses and paleosols date to the intervening stadials (Isotope Stages 2, 5d (or 6?) and probably 8). On the basis of transgressive beach facies, back barrier swamps and barrier-blocked lake deposits, a partial sea-level curve including data from Isotope Stage 5 is presented. Our data indicate that Banks Peninsula has been tectonically stable over that period and we provide sea-level points that support the existing isotope curve during Stages 5 and 6.
    [Show full text]
  • The Vulnerability of Tuhaitara Coastal Park to Rising Sea-Levels
    The Vulnerability of Tuhaitara Coastal Park to Rising Sea-levels S. Whitelaw October 13, 2011 The Vulnerability of Tuhaitara Coastal Park to Rising Sea-levels. S. Whitelaw, 2011. 1 Table of Contents Summary ..............................................................................................................................3 1. Introduction......................................................................................................................4 2. Background ......................................................................................................................4 2.1 Tuhaitara Coastal Park ..........................................................................................................4 2.2 Planning framework ...............................................................................................................6 2.3 Summary of sea-level drivers.................................................................................................7 2.4 Overview of climate change....................................................................................................8 2.5 Geomorphology and coastal processes of Pegasus Bay .....................................................13 Recent Quaternary evolution .............................................................................................13 Contemporary morphology................................................................................................14 Dunelands .....................................................................................................................15
    [Show full text]
  • The Evolution and Environmental History of Wainono Lagoon, New Zealand
    The Evolution and Environmental History of Wainono Lagoon, New Zealand A Thesis submitted in fulfilment of the requirements for the degree of Master of Science in Geography at the University of Canterbury Maki Norman Student number: 31612830 Geography Department University of Canterbury Christchurch 2016 Table of Contents Abstract ............................................................................................................................................ i Glossary of key Māori Terms ........................................................................................................ iii Acknowledgements ........................................................................................................................ iv Chapter 1. Introduction ............................................................................................................... 1 1.1 Thesis statement ................................................................................................................ 1 1.2 Conceptual context ........................................................................................................... 2 1.2.1 Coastal lagoons ......................................................................................................... 2 1.2.2 Coastal barriers ......................................................................................................... 4 1.2.3 Long-term lagoon stability status............................................................................ 10 1.2.4 Classification
    [Show full text]
  • Principal Sources of Summer Sediment to Lake Forsyth/Wairewa
    Principal Sources of Summer Sediment to Lake Forsyth/Wairewa Summer Scholarship Report WCFM Report 2013-003 REPORT: WCFM Report 2013-003 TITLE: Principal sources of summer sediment input to Lake Forsyth/ Wairewa PREPARED FOR: Waterways Centre for Freshwater Management PREPARED BY: Jordan Miller (BSc Geography) EDITED & REVISED BY: Professor Jenny Webster-Brown (WCFM) REVIEWED BY: Dr Tom Cochrane (Civil and Natural Resources Engineering) AFFILIATION: Waterways Centre for Freshwater Management University of Canterbury & Lincoln University Private Bag 4800 Christchurch New Zealand DATE: 29 March, 2013 2 Executive Summary Lake Forsyth/Wairewa is a shallow eutrophic lake on the southern coast of Banks Peninsula, Canterbury, New Zealand. It has suffered from sporadic algal blooms over the last century, which have affected water quality and lake ecology. The high phosphorus content of the lake sediment has been identified as a key driver for the algal blooms. The purpose of this study was to quantify the volume of sediment entering Wairewa through tributary rivers and streams, and via direct runoff during storms, over the summer of 2012-13. The results will contribute to a concurrent assessment of sediment-associated phosphorus input to the lake. There are only two permanent tributaries to Wairewa; the Okana and the Okuti Rivers. The remaining tributaries are all ephemeral, flowing only during heavy rainfall. Sampling and analysis for total suspended sediment (TSS) was carried out immediately following rainfall events on four occasions in December 2012 and January 2013. There were only three days when the daily rainfall exceeded 20 mm. Water loggers were installed in the Okuti and Okana Rivers and in Catons Culvert, to continuously record water level.
    [Show full text]