DOCSLIB.ORG

The Development of Rock Coast Morphology on Lord Howe Island, Australia Mark Edward Dickson University of Wollongong

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Development of Rock Coast Morphology on Lord Howe Island, Australia Mark Edward Dickson University of Wollongong University of Wollongong Research Online University of Wollongong Thesis Collection University of Wollongong Thesis Collections 2002 The development of rock coast morphology on Lord Howe Island, Australia Mark Edward Dickson University of Wollongong Recommended Citation Dickson, Mark Edward, The development of rock coast morphology on Lord Howe Island, Australia, Doctor of Philosophy thesis, School of Geosciences, University of Wollongong, 2002. http://ro.uow.edu.au/theses/1987 Research Online is the open access institutional repository for the University of Wollongong. For further information contact the UOW Library: [email protected] THE DEVELOPMENT OF ROCK COAST MORPHOLOGY ON LORD HOWE ISLAND, AUSTRALIA A thesis submitted in fulfilment of the requirements for the award of the degree of DOCTOR OF PHILOSOPHY from UNIVERSITY OF WOLLONGONG by MARK EDWARD DICKSON (BSc. Hons, Massey University) SCHOOL OF GEOSCIENCES UNIVERSITY OF WOLLONGONG 2002 This work has not been submitted for a higher degree at any other academic institution and, unless otherwise acknowledged, is my own work. Mark Edward Dickson Lord Howe Island, southwest Pacific 1 Abstract Lord Howe Island, situated 600 km east of Australia, provides a unique opportunity to study the development of rock coast landforms and the long-term planation of an oceanic island. The island is a remnant of a large shield volcano that was built by late-Miocene hotspot volcanism. Since this time, the island has gradually migrated northward into warmer seas, and marine planation, operating at a decreasing rate over time, has reduced the island to a vestige of the original volcano. Lord Howe Island currently lies at the southern limit to coral growth. A fringing coral reef has developed on only the western side of the island, such that one side of the island is very effectively sheltered from wave attack, while the other side is exposed to waves of unlimited fetch. The contrast between landforms on each of these coastlines provides a clear illustration of the importance of wave erosion in rock coast evolution: the reef-protected coastline consists of depositional beaches, vegetated hillslopes, diminutive cliffs, and basalt shore platforms that are veneered with talus, whereas the exposed coastline includes precipitous basalt cliffs up to 800 m high that are plunging or have cliff-foot talus slopes, and cliffs 200 m or less high that have actively eroding shore platforms. Variation in rock resistance also exerts a clear control on coastal morphology at Lord Howe Island. Rock resistance was assessed through Schmidt Hammer testing as well as measurements taken on discontinuities within rocks, and wave characteristics were assessed with bathymetric data and data on the local wave climate. At Lord Howe Island, talus slopes occur beneath cliffs where a critical size of cliff face has supplied sufficient talus to offset wave abrasion and removal of talus during the Holocene highstand. Plunging cliffs or shore platforms occur where source areas are smaller. In some areas, a critical depth of water prevents waves from breaking against the cliff face and plunging cliffs occur irrespective of rock resistance. Where water depths are shallower, however, plunging cliffs only exist if the resistance of rocks exceeds the assailing force of waves. In this respect, time is a crucial factor, as rock resistance is gradually degraded by weathering processes. Type B shore platforms have developed along sections of coast where the assailing force of waves has exceeded rock resistance. There is a close positive correlation between the elevation of shore platforms and nearshore water depth, and this indicates the important role of breaking waves in shore platform formation at Lord Howe Island. Several other factors indicate that platforms at Lord Howe Island have been strongly influenced by wave erosion, particularly the fact that platforms on the exposed coastline are wider than platforms on the lagoonal coastline. However, weathering processes become more important as platform width increases, and platforms become lower and flatter as they become wider. This thesis proposes a four-stage model of Type B, microtidal shore platform development at Lord Howe Island. The model attempts to synthesise divergent hypotheses in the literature with a time-based perspective of platform evolution. 11 Acknowledgements This thesis has benefited enormously from the excellent supervision provided by Assc. Prof. Colin Woodroffe. Colin has been enthusiastic for the project throughout its course and has been a ready source of advice and debate. I am particularly thankful for his rapid and critical appraisals of draft chapters. Two of my postgraduate colleagues, Dr. Brendan Brooke and Dr. David Kennedy, have each completed PhD theses on aspects of the geology/geomorphology of Lord Howe Island. Both have spent time with me in the field, and both have been a tremendous source of information and discussion. I am particularly grateful to Dave for his assistance and advice through several weeks of fieldwork. Assc. Prof. Brian Jones accompanied me in the field for a period and had an important influence on my understanding of rock coasts. I am also thankful for the fieldwork assistance provided by Sunayani Dey, John de Carli, and the crews of RV Franklin and Advance II. The Lord Howe Island Board has provided much-needed technical support throughout my research. In this capacity, particular thanks are due to Cristopher Haselden and Dean Hiscox. From time to time I have discussed aspects of my research with academics at the University of Wollongong and other institutions. In particular, I would like to acknowledge the advice of Assc. Prof. Edward Bryant, Prof. Robert Young, Prof. Ian McDougall, Dr. Wayne Stephenson, Dr. Paul Augustinus, and Prof. John Chappell. The extensive postgraduate community at the University of Wollongong has also been a source of advice and discussion. In particular, I would like to acknowledge Daniel Palamara, for his technical and analytical dexterity on a number of matters. Sue Murray has been a ready source of advice, and Ben Ackerman prepared laboratory samples. Bathymetric data was provided under license from the Royal Australian Navy (Hydrographic Office); thanks are due to Patrick Roche for his assistance with the difficult task of merging this data. Climate and wave data was purchased from the Australian Bureau of Meteorology, Environment Australia supplied regional satellite wave data, and the National Tidal Facility (Flinders University) and Manly Hydraulics Laboratory provided tidal data. Thanks are due to Col Nalty (MHL) for calculating tidal planes, and also Edward Bryant and Milena Mascarenhes for the use of a spreadsheet for calculating wave characteristics. Aerial photographs were purchased from the Land Information Centre, and some oblique photographs were provided by Edward Bryant, Ian Ul Hutton, David Kennedy, and Colin Woodroffe; special thanks are due to Ian Hutton for the use of his collection of slides. Financial support throughout my tenure has been provided by a University Postgraduate Award, and research costs were covered by a grant from the Australian Research Council to Colin Woodroffe and Brian Jones. On a personal note, I would like to acknowledge the support of my parents throughout my education, and the support of my fiancee Sunayani during the course of this thesis. Sunayani provided cheerful assistance in the field, despite sometimes trying conditions, helped to correct a number of chapter drafts, and provided a source of encouragement and discussion that is very much appreciated. iv Table of Contents Abstract i Acknowledgements ii Table of Contents iv List of Figures viii List of Tables xiii List of Appendices xiv 1. Introduction 1 2. Literature review 8 2.1 Introduction 8 2.2 Erosion of oceanic islands 8 2.2.1 The process of marine cliff cutting 11 2.2.2 Giant landslides and tsunami 14 2.2.3 Summary of erosion of oceanic islands 17 2.3 Processes 18 2.3.1 Wave erosion 19 Erosive processes generated by waves 22 2.3.2 Subaerial weathering 25 2.3.3 Solution and biological erosion 26 2.4 Rock coast morphology 28 2.4.1 Shore platforms 30 Synopsis of a long-standing debate 31 Incipient platforms 34 The elevation at which shore platforms develop 37 Cliff retreat and shore platform widening 44 Weathering of shore platforms 53 2.4.2 Plunging cliffs 57 Formation of plunging cliffs 59 Destruction of plunging cliffs 61 V Demarcation between shore platforms and plunging cliffs 63 2.4.3 Summary of rock coast morphologies 65 3. Geological and geomorphological evolution of Lord Howe Island 66 3.1 Tectonic setting 66 3.2 Geological evolution 67 3.2.1 Roach Island Tuff 67 3.2.2 North Ridge Basalt 67 3.2.3 Boat Harbour Breccia 70 3.2.4 Mount Lidgbird Basalt 73 3.2.5 Summary of geological evolution 75 3.3 Marine planation following volcanic activity .75 3.4 History of aeolianite deposition 77 3.5 Holocene shoreline evolution 81 3.6 Summary 83 4. Description of rock coast landforms 84 4.1 Introduction 84 4.2 Roach Island Tuff 86 4.3 North Ridge Basalt 91 4.3.1 North Ridge cliffs 91 4.3.2 Dawsons Point 96 4.3.3 Clear Place Point and Blinky Point 96 4.3.4 Sail Rock and Mutton Bird Island 99 4.4 Boat Harbour Breccia 102 4.5 Mount Lidgbird Basalt 106 4.6 Calcarenite 112 4.7 Summary 117 5. Resistance of rocks and erosive force of waves 118 5.1 Introduction 118 5.2 Rock resistance 118 5.2.1 Rock hardness 120 5.2.2 Geomorphological applications of the Schmidt Hammer 123 vi 5.2.3 Discontinuities 124 5.2.4 Methodology for evaluating rock resistance 125 5.2.5 Rock resistance results 128 Spatial distribution of Schmidt Hammer tests, outliers, and repeatability of tests 128 Rock hardness overview 132 Hardness of rocks and the extent of weathering 134 Roach Island Tuff.
Load more

Recommended publications
  • Regional Development Australia Mid North Coast
    Mid North Coast [Connected] 14 Prospectus Contents Mid North Coast 3 The Regional Economy 5 Workforce 6 Health and Aged Care 8 Manufacturing 10 Retail 12 Construction 13 Education and Training 14 The Visitor Economy 16 Lord Howe Island 18 Financial and Insurance Services 19 Emerging Industries 20 Sustainability 22 Commercial Land 23 Transport Options 24 Digitally Connected 26 Lifestyle and Housing 28 Glossary of Terms 30 Research Sources 30 How can you connect ? 32 Cover image: Birdon Group Image courtesy of Port Macquarie Hastings Council Graphic Design: Revive Graphics The Mid North Coast prospectus was prepared by Regional Development Australia Mid North Coast. Content by: Justyn Walker, Communications Officer Dr Todd Green, Research & Project Officer We wish to thank the six councils of the Mid North Coast and all the contributors who provided images and information for this publication. MID NORTH COAST NSW RDA Mid North Coast is a not for profit organisation funded by the Federal Government and the NSW State Government. We are made up of local people, developing local solutions for the Mid North Coast. Birdon boat building Image2 Mid cou Northrtesy of PortCoast Macquarie Prospectus Hastings Council Mid North Coast The Mid North Coast is the half-way point connecting Sydney and Brisbane. It comprises an area of 15,070 square kilometres between the Great Divide and the east coast. Our region is made up of six local government areas: Coffs Harbour, Bellingen, Nambucca, Kempsey, Port Macquarie – Hastings and Greater Taree. It also includes the World Heritage Area of Lord Howe Island. It is home to an array of vibrant, modern and sometimes eclectic townships that attract over COFFS 4.9 million visitors each year.
    [Show full text]
  • AMS112 1978-1979 Lowres Web
    --~--------~--------------------------------------------~~~~----------~-------------- - ~------------------------------ COVER: Paul Webber, technical officer in the Herpetology department searchers for reptiles and amphibians on a field trip for the Colo River Survey. Photo: John Fields!The Australian Museum. REPORT of THE AUSTRALIAN MUSEUM TRUST for the YEAR ENDED 30 JUNE , 1979 ST GOVERNMENT PRINTER, NEW SOUTH WALES-1980 D. WE ' G 70708K-1 CONTENTS Page Page Acknowledgements 4 Department of Palaeontology 36 The Australian Museum Trust 5 Department of Terrestrial Invertebrate Ecology 38 Lizard Island Research Station 5 Department of Vertebrate Ecology 38 Research Associates 6 Camden Haven Wildlife Refuge Study 39 Associates 6 Functional Anatomy Unit.. 40 National Photographic Index of Australian Director's Research Laboratory 40 Wildlife . 7 Materials Conservation Section 41 The Australian Museum Society 7 Education Section .. 47 Letter to the Premier 9 Exhibitions Department 52 Library 54 SCIENTIFIC DEPARTMENTS Photographic and Visual Aid Section 54 Department of Anthropology 13 PublicityJ Pu bl ications 55 Department of Arachnology 18 National Photographic Index of Australian Colo River Survey .. 19 Wildlife . 57 Lizard Island Research Station 59 Department of Entomology 20 The Australian Museum Society 61 Department of Herpetology 23 Appendix 1- Staff .. 62 Department of Ichthyology 24 Appendix 2-Donations 65 Department of Malacology 25 Appendix 3-Acknowledgements of Co- Department of Mammalogy 27 operation. 67 Department of Marine
    [Show full text]
  • Evaluation of the Coastal Inundation and Erosion Process in the Mid-West Coast of Western Australia
    Faculty of Science and Engineering School of Civil and Mechanical Engineering Evaluation of the coastal inundation and erosion process in the Mid-West coast of Western Australia Withanage Sajantha Lakmali Perera This thesis is presented for the Degree of Master of Philosophy (Civil Engineering) of Curtin University September 2016 Abstract At present the coastal inundation and erosion is a major problem all around the world and this issue will be more severe in the future due to sea level rise. Australia has a long coastline around the country, thus it focus on the coastal vulnerability due to sea level rise. Taking these facts into account, this research was focused on the evaluation of the coastal inundation and erosion process in the Mid-West coast of Western Australia. Within the Mid-West region, a seventy five kilometre stretch was selected for the study. The major highlight of this research is the integrated modelling approach and the result of the modelling carried out for evaluation of the coastal inundation and erosion process. Widely used coastal model, MIKE 21 was selected as the dynamic model for the study. As data plays very important part for this research, an intensive data collection campaign was conducted to collect the required data. Bathymetry data, coastal boundary data, topography data, wave, water levels and wind data, were collected using discrete data sources from variety of government, local and private organizations. Extreme value analysis for water levels, wind and wave was done using Gumbel and Weibull distributions. The final results of the inundation and erosion extends have been presented in terms of spatial maps.
    [Show full text]
  • A Guide to the Birds of Barrow Island
    A Guide to the Birds of Barrow Island Operated by Chevron Australia This document has been printed by a Sustainable Green Printer on stock that is certified carbon in joint venture with neutral and is Forestry Stewardship Council (FSC) mix certified, ensuring fibres are sourced from certified and well managed forests. The stock 55% recycled (30% pre consumer, 25% post- Cert no. L2/0011.2010 consumer) and has an ISO 14001 Environmental Certification. ISBN 978-0-9871120-1-9 Gorgon Project Osaka Gas | Tokyo Gas | Chubu Electric Power Chevron’s Policy on Working in Sensitive Areas Protecting the safety and health of people and the environment is a Chevron core value. About the Authors Therefore, we: • Strive to design our facilities and conduct our operations to avoid adverse impacts to human health and to operate in an environmentally sound, reliable and Dr Dorian Moro efficient manner. • Conduct our operations responsibly in all areas, including environments with sensitive Dorian Moro works for Chevron Australia as the Terrestrial Ecologist biological characteristics. in the Australasia Strategic Business Unit. His Bachelor of Science Chevron strives to avoid or reduce significant risks and impacts our projects and (Hons) studies at La Trobe University (Victoria), focused on small operations may pose to sensitive species, habitats and ecosystems. This means that we: mammal communities in coastal areas of Victoria. His PhD (University • Integrate biodiversity into our business decision-making and management through our of Western Australia)
    [Show full text]
  • Developing Impact-Based Thresholds for Coastal Inundation from Tide Gauge Observations
    CSIRO PUBLISHING Journal of Southern Hemisphere Earth Systems Science, 2019, 69, 252–272 https://doi.org/10.1071/ES19024 Developing impact-based thresholds for coastal inundation from tide gauge observations Ben S. HagueA,B,C, Bradley F. MurphyA, David A. JonesA and Andy J. TaylorA ABureau of Meteorology, GPO Box 1289, Melbourne, Vic. 3001, Australia. BSchool of Earth, Atmosphere and Environment, Monash University, Clayton, Vic., Australia. CCorresponding author. Email: [email protected] Abstract. This study presents the first assessment of the observed frequency of the impacts of high sea levels at locations along Australia’s northern coastline. We used a new methodology to systematically define impact-based thresholds for coastal tide gauges, utilising reports of coastal inundation from diverse sources. This method permitted a holistic consideration of impact-producing relative sea-level extremes without attributing physical causes. Impact-based thresh- olds may also provide a basis for the development of meaningful coastal flood warnings, forecasts and monitoring in the future. These services will become increasingly important as sea-level rise continues.The frequency of high sea-level events leading to coastal flooding increased at all 21 locations where impact-based thresholds were defined. Although we did not undertake a formal attribution, this increase was consistent with the well-documented rise in global sea levels. Notably, tide gauges from the south coast of Queensland showed that frequent coastal inundation was already occurring. At Brisbane and the Sunshine Coast, impact-based thresholds were being exceeded on average 21.6 and 24.3 h per year respectively. In the case of Brisbane, the number of hours of inundation annually has increased fourfold since 1977.
    [Show full text]
  • FF Directory
    Directory WFF (World Flora Fauna Program) - Updated 30 November 2012 Directory WorldWide Flora & Fauna - Updated 30 November 2012 Release 2012.06 - by IK1GPG Massimo Balsamo & I5FLN Luciano Fusari Reference Name DXCC Continent Country FF Category 1SFF-001 Spratly 1S AS Spratly Archipelago 3AFF-001 Réserve du Larvotto 3A EU Monaco 3AFF-002 Tombant à corail des Spélugues 3A EU Monaco 3BFF-001 Black River Gorges 3B8 AF Mauritius I. 3BFF-002 Agalega is. 3B6 AF Agalega Is. & St.Brandon I. 3BFF-003 Saint Brandon Isls. (aka Cargados Carajos Isls.) 3B7 AF Agalega Is. & St.Brandon I. 3BFF-004 Rodrigues is. 3B9 AF Rodriguez I. 3CFF-001 Monte-Rayses 3C AF Equatorial Guinea 3CFF-002 Pico-Santa-Isabel 3C AF Equatorial Guinea 3D2FF-001 Conway Reef 3D2 OC Conway Reef 3D2FF-002 Rotuma I. 3D2 OC Conway Reef 3DAFF-001 Mlilvane 3DA0 AF Swaziland 3DAFF-002 Mlavula 3DA0 AF Swaziland 3DAFF-003 Malolotja 3DA0 AF Swaziland 3VFF-001 Bou-Hedma 3V AF Tunisia 3VFF-002 Boukornine 3V AF Tunisia 3VFF-003 Chambi 3V AF Tunisia 3VFF-004 El-Feidja 3V AF Tunisia 3VFF-005 Ichkeul 3V AF Tunisia National Park, UNESCO-World Heritage 3VFF-006 Zembraand Zembretta 3V AF Tunisia 3VFF-007 Kouriates Nature Reserve 3V AF Tunisia 3VFF-008 Iles de Djerba 3V AF Tunisia 3VFF-009 Sidi Toui 3V AF Tunisia 3VFF-010 Tabarka 3V AF Tunisia 3VFF-011 Ain Chrichira 3V AF Tunisia 3VFF-012 Aina Zana 3V AF Tunisia 3VFF-013 des Iles Kneiss 3V AF Tunisia 3VFF-014 Serj 3V AF Tunisia 3VFF-015 Djebel Bouramli 3V AF Tunisia 3VFF-016 Djebel Khroufa 3V AF Tunisia 3VFF-017 Djebel Touati 3V AF Tunisia 3VFF-018 Etella Natural 3V AF Tunisia 3VFF-019 Grotte de Chauve souris d'El Haouaria 3V AF Tunisia National Park, UNESCO-World Heritage 3VFF-020 Ile Chikly 3V AF Tunisia 3VFF-021 Kechem el Kelb 3V AF Tunisia 3VFF-022 Lac de Tunis 3V AF Tunisia 3VFF-023 Majen Djebel Chitane 3V AF Tunisia 3VFF-024 Sebkhat Kelbia 3V AF Tunisia 3VFF-025 Tourbière de Dar.
    [Show full text]
  • Impact of Sea Level Rise on Coastal Natural Values in Tasmania
    Impact of sea level rise on coastal natural values in Tasmania JUNE 2016 Department of Primary Industries, Parks, Water and Environment Acknowledgements Thanks to the support we received in particular from Clarissa Murphy who gave six months as a volunteer in the first phase of the sea level rise risk assessment work. We also had considerable technical input from a range of people on various aspects of the work, including Hans and Annie Wapstra, Richard Schahinger, Tim Rudman, John Church, and Anni McCuaig. We acknowledge the hard work over a number of years from the Sea Level Rise Impacts Working Group: Oberon Carter, Louise Gilfedder, Felicity Faulkner, Lynne Sparrow (DPIPWE), Eric Woehler (BirdLife Tasmania) and Chris Sharples (University of Tasmania). This report was compiled by Oberon Carter, Felicity Faulkner, Louise Gilfedder and Peter Voller from the Natural Values Conservation Branch. Citation DPIPWE (2016) Impact of sea level rise on coastal natural values in Tasmania. Natural and Cultural Heritage Division, Department of Primary Industries, Parks, Water and Environment, Hobart. www.dpipwe.tas.gov.au ISBN: 978-1-74380-009-6 Cover View to Mount Cameron West by Oberon Carter. Pied Oystercatcher by Mick Brown. The Pied Oystercatcher is considered to have a very high exposure to sea level rise under both a national assessment and Tasmanian assessment. Its preferred habitat is mudflats, sandbanks and sandy ocean beaches, all vulnerable to inundation and erosion. Round-leaved Pigface (Disphyma australe) in flower in saltmarsh at Lauderdale by Iona Mitchell. Three saltmarsh communities are associated with the coastal zone and are considered at risk from sea level rise.
    [Show full text]
  • MELBOURNE Bushwalkers Inc
    THE NEWS OFTiffi MELBOURNE BUSHWALKERS MELBOURNE BusHWALKERS INc. EDmoN 633 NOVEMBER 2003 60 CENTS Lavender Fest Weekend: 22 & 23 November Warratina Lavender Farm Quayle Road, Wandin Yallock (Me/way: 121 El.) Featuring: musical and dancing entertainment, alpacas, market stalls, animal farm, craft demonstrations and Club Barbeque wine and food of the Yarra Valley. Entry is $5 Wednesday 26 November ($3 cone.) and children under 12 years are free. Spit roast dinner on Saturday night (b.y.o.): 7- 11 pm. 7- 9 pm, Clubrooms There will be late night jazz and rock. Tickets are $35 per person. Summer is just around the comer.. Come along to this Bushies barbeque in late November. The club will Anyone interested in going on the Saturday please provide all the food and drinks for just $10 per head. speak to Lynda Larkin in advance so we can organize a car pool. Please phone +Letter Writing Night If you'd rather eat a cow than walk with one .. We will also have a letter writing campaign on this barbeque night regarding: 1) cows in the Alpine National Park and 2) the ACF campaign for the River Murray asking for a national management plan. MBWChristmas Party It's easy: pre-written letters will be available which can be signed and sent and there will also be paper if you Wednesday 17 December wish to use your own words. Come and have your say on these issues that affect both the enjoyment of club walks and the health of Australian wildlife. See William Cone, Secretary in the clubrooms if you would like to take part.
    [Show full text]
  • Chevron-Shaped Accumulations Along the Coastlines of Australia As Potential Tsunami Evidences?
    CHEVRON-SHAPED ACCUMULATIONS ALONG THE COASTLINES OF AUSTRALIA AS POTENTIAL TSUNAMI EVIDENCES? Dieter Kelletat Anja Scheffers Geographical Department, University of Duisburg-Essen Universitätsstr. 15 D-45141 Essen, Germany e-mail: [email protected] ABSTRACT Along the Australian coastline leaf- or blade-like chevrons appear at many places, sometimes similar to parabolic coastal dunes, but often with unusual shapes including curvatures or angles to the coastline. They also occur at places without sandy beaches as source areas, and may be truncated by younger beach ridges. Their dimensions reach several kilometers inland and altitudes of more than 100 m. Vegetation development proves an older age. Judging by the shapes of the chevrons at some places, at least two generations of these forms can be identified. This paper dis- cusses the distribution patterns of chevrons (in particular for West Australia), their various appearances, and the possible genesis of these deposits, based mostly on the interpretations of aerial photographs. Science of Tsunami Hazards, Volume 21, Number 3, page 174 (2003) 1. INTRODUCTION The systematic monitoring of tsunami during the last decades has shown that they are certainly not low frequency events: on average, about ten events have been detected every year – or more than 1000 during the last century (Fig. 1, NGDC, 2001) – many of which were powerful enough to leave imprints in the geological record. Focusing only on the catastrophic events, we find for the last 400 years (Fig. 2, NGDC, 2001) that 92 instances with run up of more than 10 m have occurred, 39 instances with more than 20 m, and 14 with more than 50 m, or – statistically and without counting the Lituya Bay events – one every 9 years with more than 20 m run up worldwide.
    [Show full text]
  • Lepidorrhachis Mooreana (H
    Palm Conservation – Palm Specialist Group Lepidorrhachis mooreana (H. Wendl. & Drude) O. F. Cook Status: Not Evaluated in IUCN Red List. Vulnerable according to Dowe in Johnson (1996). Preliminary evaluation based on IUCN 2001 criteria: Endangered (EN B1a,bv) Common name Little Mountain Palm. Natural range Lepidorrhachis mooreana is restricted to the summits of Mt. Gower (875 m) and Mt. Lidgbird (777 m) on the remote Lord Howe Island. It occurs only above 750 m in dwarf mossy forest that dominates the summit plateau of Mt. Gower and the narrow summit ridge of Mt. Lidgbird. This forest is home to numerous remarkable endemic species including the pumpkin tree (Negria rhabdothamnoides), an arborescent member of the Gesneriaceae, and Dracophyllum fitzgeraldii (Ericaceae). It is also the primary nesting locality of the providence petrel (Pterodroma solandri) and is a stronghold for the woodhen (Tricholimnas sylvestris), an endemic member of the rail family that was recently rescued from the brink of extinction. However, less that 0.5 km2 of Lord Howe’s total surface area of 12 km2 is found above 750 m. The total area of suitable habitat available to Lepidorrhachis is thus extremely limited. Recognition characteristics Lepidorrhachis is very easily distinguished from the two other endemic palm genera on Lord Howe Island, Howea and Hedyscepe. It is a short solitary palm with a stem that rarely exceeds 2 m in height. It has stiff, arching leaves with short, deeply split leaf sheaths that do not form a distinct crownshaft. The sheaths are also covered with buff indumentum. Its bushy inflorescences are born below the leaves and are unisexual, both male and female inflorescences occurring on the same plant.
    [Show full text]
  • The Role of Fieldwork in Rock Decay Research
    Geomorphology 200 (2013) 59–74 Contents lists available at ScienceDirect Geomorphology journal homepage: www.elsevier.com/locate/geomorph The role of fieldwork in rock decay research: Case studies from the fringe Ronald I. Dorn a,⁎, Steven J. Gordon b, Casey D. Allen c, Niccole Cerveny d, John C. Dixon e, Kaelin M. Groom e, Kevin Hall f, Emma Harrison a, Lisa Mol g, Thomas R. Paradise e, Paul Sumner h, Tyler Thompson a, Alice V. Turkington i a School of Geographical Sciences and Urban Planning, Box 875302, Arizona State University, Tempe, AZ 85287–5302, USA b Department of Economics and Geography, United States Air Force Academy, 2354 Fairchild Drive, Colorado Springs, CO 80840–6299, USA c Department of Geography and Environmental Sciences, University of Colorado Denver, P.O. Box 173364, Campus Box 172, Denver, CO 80217–3364, USA d Cultural Sciences Department, Mesa Community College, 7110 East McKellips Road, Mesa, AZ 85207, USA e Department of Geosciences, University of Arkansas, Fayetteville, AR 72701, USA f Department of Geography, University of Northern British Columbia, Prince George, British Columbia, Canada V2N 4Z9 g School of Geography and the Environment, South Parks Road, University of Oxford, OX1 3QY, UK h Department of Geography, Geoinfomatics and Meteorology, University of Pretoria, South Africa i Department of Geography, University of Kentucky, 1457 Patterson Office Tower, Lexington, KY 40506–0027, USA article info abstract Article history: Researchers exploring rock decay hail from chemistry, engineering, geography, geology, paleoclimatology, Received 22 September 2012 soil science, and other disciplines and use laboratory, microscopic, theoretical, and field-based strategies. Received in revised form 12 December 2012 We illustrate here how the tradition of fieldwork forms the core knowledge of rock decay and continues to Accepted 12 December 2012 build on the classic research of Blackwelder, Bryan, Gilbert, Jutson, King, Linton, Twidale, and von Humboldt.
    [Show full text]
  • Discover the History of Warrnambool's Streets
    Discover the history of Warrnambool's streets Street Name Description Locality Length Origin of Street Name Abbey Lane A laneway running between Hyland and Hart Streets, south of Timor Warrnambool 495m Benjamin Abbey (1862-1943) served two terms as Councillor 1913-16 and 1920-30. Served as Mayor 1924-26 during the Street. building of the Municipal Chambers. He was Manager of the Warrnambool branch of the Co-Operative Box Works of Victoria situated in South Warrnambool and a Trustee of the Methodist Church. His first wife Annie (nee Newman) died in Appears, unnamed, on an 1890 map. 1916 and his 2nd wife, Anastasia, died in 1994. This unnamed road was named Abbey Lane by the City of Warrnambool on 29th April 1991. The Council minutes and Government Gazette specifically name only the section between Hart and Hyland Streets which means the section between Hart and Ryot Streets is technically still unnamed. Aberline Road A northerly continuation of McKiernan Road, running from the Moore Warrnambool 1917m Joseph Aberline (1809-1874) arrived in Warrnambool in 1849 after spending some years in New Zealand. His property, Street/Dales Road intersection north to Wangoom Road. "The Grove", built on Wangoom Road in the 1860s was the site of a brick-making enterprise established by his son, John (1854-1940) in 1891. It was from the Wangoom Road property that large boulders were taken for use as some of the filling A very old road that appears on an 1856 map of Warrnambool. for the Warrnambool breakwater. Some older maps call it Aberlines Road.
    [Show full text]