Macquarie University
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Offshore bathymetry and sediment patterns of Sydney beaches

posted on 2022-03-28, 12:08 authored by John Hann
The submarine topography and the pattern of surface sediment has been examined for twelve Sydney beaches in an attempt to define the seaward boundary of the active sediment zone for each beach. -- The bathymetry is dominated by inherited bedrock forms and the basement topography exhibits evidence of prolonged periods of low sea level and former still stands. The sand bodies associated with each beach fill relict drainage channels and the channel interfluves form extensive areas of exposed rock. -- Two texturally distinct sand bodies are identified. An inshore sequence of seaward fining grain size and an offshore belt of coarser material. A textural discontinuity marking the interface between these two sand bodies and the seaward boundary of the active zone is manifest at only three beaches. The seaward boundary at the other beaches is marked by rock. -- Each beach has strongly individual textural characteristics. Grain size gradings occur along the coast, and along individual beaches. This pattern can be related to the irregular nature of the bathymetry, causing an uneven distribution of wave height at the shoreline. A model of offshore bathymetry and sediment patterns for the Sydney beaches is presented.


Table of Contents

1. Introduction -- 2. The Sydney Coast: solid boundaries, quaternary history and sediments -- 3. The Sydney Coast: marine energy and sediment dynamics -- 4. Bathymetry: survey methods and coverage and submarine topography -- 5. Sediments: methods of sampling and analysis and sediment patterns -- 6. The relationship between wave energy, bathymetry and sediments -- APPENDICES -- 1. Map compilation -- 2. M.W.S.D.B. surveys -- 3. Sediment data: a. Total sample b. Carbonate removed -- 4. Assumptions made for wave refraction calculations.


Bibliography: p. 116-121

Awarding Institution

Macquarie University

Degree Type

Thesis bachelor honours


Thesis (BA (Hons)), Macquarie University

Year of Award


Principal Supervisor

J. L. Davies

Additional Supervisor 1

Andy Short


Copyright disclaimer: Copyright John Hann 1979. This thesis was digitised for the purposes of Document Delivery. Macquarie University ResearchOnline attempted to locate the author but where this has not been possible; we are making available, open access, the thesis which may be used for the purposes of private research and study. If you have any enquiries or issues regarding this work being made available please contact Macquarie University ResearchOnline - If you wish to access the complete thesis, on receipt of a Document Supply Request, placed with Macquarie University Library by another library, we will consider supplying a copy of this thesis. For more information on Document Supply, please contact




New South Wales


1 online resource (xi, 121 p.) ill. (some col.) , maps (some col.)

Former Identifiers

mq:25461 1860343