L.Goil Gravity Core 5 04/02/76

https://theses.gla.ac.uk/ Theses Digitisation: https://www.gla.ac.uk/myglasgow/research/enlighten/theses/digitisation/ This is a digitised version of the original print thesis. Copyright and moral rights for this work are retained by the author A copy can be downloaded for personal non-commercial research or study, without prior permission or charge This work cannot be reproduced or quoted extensively from without first obtaining permission in writing from the author The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the author When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given Enlighten: Theses https://theses.gla.ac.uk/ [email protected] TRACER APPLICATIONS OF RADIOCAESIUM IN A COASTAL MARINE ENVIRONMENT Thesis submitted to the University of Glasgow in fulfilment of the requirements for the degree of Doctor of Philosophy By IAN GERARD MC KINLEZ AUGUST 1979 CHEMISTRY DEPARTMENT UNIVERSITY OF GLASGOW GLASGOW G12 8QQ ProQuest Number: 10984294 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a com plete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest ProQuest 10984294 Published by ProQuest LLC(2018). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States C ode Microform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106- 1346 Acknowledgements I gratefully acknowledge the invaluable supervision ,encouragement and advice given by Dr.M.S.Baxter throughout this project.Special mention must also be made of the continual assistance and provision of counting facilities by Dr.W.Jack and the considerable aid given by Dr.A.B.MacKenzie on whose initial work much of this thesis is based.Thanks for assistance during this research are extended to Dr.T.Leatherland,the crew of R.V. Endrick II and the Clyde River Purification Board for provision of ship time,hydrographic data and aid in sample collection;Dr.D.J.Ellett and the Scottish Marine Biological Association for collection of samples and provision of hydrographic data;A.G.Ballantyne,K.MacKay,D.McKie and D. Thompson for occasional technical assistance;J.McKinley,S.Flynn and D. Quigley for programming aid and the Chemistry Dept. Electronic,Mechanical and Glassblowing Workshops for construction and maintenance of equipment. The advice and help of past and present members ( and associates ) of the Nuclear Geochemistry Group has contributed greatly to this work,of whom special thanks to John Campbell,Ron Crawford,Josephine Docherty,Nina Drndarsky,Tony Fallick,John Farmer,Gus Mackenzie,Fred Mackie,Asizan Saad, Jane Smith-Briggs,Mike Stenhouse and Dave Swan who provided a most congenial social and scientific environment.I am grateful to I.Durant for typing this manuscript and especially so to Linda Kemp for preparation of tables,diagrams,references,proof-reading and continual help over the period of this project. This work would not have been possible without the support of my parents, family and friends to whom I owe an inestimable debt of gratitude. Finally,I acknowledge the support of a N.E.R.C. grant for this project. ABSTRACT In this study radiocaesium is confirmed as a versatile tracer and its use is demonstrated in the investigation of a wide range of processes occuring in the coastal marine environment. By utilising an analogue model, radiocaesium transport from Windscale to the North Channel may be characterised by a ’residence half-time* of ~12 months compounded with a ’lag time’ of ~6 months. This transport is, however, shown to be variable - in 1977 a greatly increased Atlantic influx to the Irish Sea through the St, George’s Channel was evident, resulting in an accelerated radiocaesium transport rate northwards through the North Channel, By further use of this model, the waters of the Clyde Sea Area may be shown to have a 'residence half-time’ of ^3 months with the lag between the North Channel site and the Clyde being ~1 month. Additionally, ^kCf/o of the northwards water flux from the Irish Sea may be shown to pass through the Clyde Sea Area. Transport from the North Channel to the Minch is also shown to change considerably between 1976 ( advection rater3km/day ) and 1977 ( advection rate ~1 ,5 km/day ) associated with a marked widening of the coastal water plume in the Hebridean Sea Area during this period. Consideration of the spatial radiocaesium distribution indicates that the Clyde Sea Area may be regarded as homogeneous both horizontally and vertically thus justifying the analogue model analysis. Exceptions to this generality are the deep waters of Lochs Fyne and Goil where significant residence of water in restricted basins of these fjords is proven by the measured radiocaesium profiles. Detailed study of radiocaesium / depth profiles in Loch Goil over a period of 2 years allows examination of the annual mixing cycle in this loch. By this method it Is seen that L.Goil is characterised by fast surface ( £30 m. ) exchange at all times with a limited barrier to vertical mixing developing in late spring and more extreme stratification evident in late autumn / early winter. From a one dimensional vertical diffusion treatment, Cs-13^ transport through 2 1 the early winter pycnocline may be characterised by 7 £23 cm sec • z From analysis of the radiocaesium distribution in sediment •2 *1 cores, sedimentation rates of 200, 330 and 6kO mg cm y may be calculated for the Loch Goil deep, shallow and Gareloch sites respectively. From the Cs-13^ profile in the upper layers of these cores, surface turbation (probably due to benthic organisms )may 2 -1 be characterised by 2 $ K £ 2^, K >92 and K£+3 cm y respectively at these three sites. While the Cs-137 profile in Holyloch sediment indicates an 2 1 accumulation rate of ^600 mg cm y below a surface mixed zone of "k cm depth, this site is anomalous in that the sediment contains Co-60 and Cs-13^- derived from the nearby U.S.N. nuclear submarine base. As radiocaesium is shown to have a coastal water residence time of ^950 y its treatment as a conservative v/ater tracer is justified on the timescale of nearshore oceanographic processes. In addition, however, the observed concentration factor onto sediment ( ^250 ) is sufficient for it to be used in a range of sedimentary tracer applications. By constructing a budget for Windscale released Cs-137* it may be seen that the major reservoirs of this nuclide are the immediate Windscale vicinity ( 1.8% ), the rest of the Irish Sea ( 17.3% )» the North Channel/Clyde Sea Area ( 2.0%), the North Sea ( 19*7% ) and marine sediment ( 2.6% ). After reduction of the radiocaesium inventory to account for radioactive decay, the balance may be attributed to radiocaesium lost from the coastal water system into the North Atlantic ( 37-3%)- From measurements of radiocaesium concentration factors for fish in the Clyde Sea Area, a maximal dose to a member of the public is calculated as ^11% of the I.C.R.P. limits at the time of maximum measured Cs-137 concentration in this area ( April 1977 ) although the dose to a general critical group would be much smaller - ~2% of I.C.R.P. limits. Finally, as the hydrographic data obtained from radiocaesium tracer experiments is demonstrated to be useful in many other areas of research, future developments of this technique are proposed and alternative locations for study are suggested. INDEX CHAPTER 1. INTRODUCTION 1.1 Tracer Theory 1 1.2 Radiotracer Applications 11 1.3 Radiocaesium as a Marine Environmental Tracer 28 1 .k Areas of Study kO 1.3 Aims of Research • 30 CHAPTER 2. EXPERIMENTAL 2.1 Introduction 32 2.2 Counting Systems 33 2.3 Water Samples 71 2.k Sediment and Biological Samples 83 2.3 Errors,Reproducibility and Sample Calculations 88 CHAPTER 3. THE CLYDE SEA AREA 3.1 Introduction 102 3.2 Spacial Distribution of Radiocaesium in the C.S.A. 104 3.3 Temporal Variations in the Radiocaesium Content of the C.S.A. 118 3.^ Summary 1^-1 CHAPTER THE NORTHERN SEA LOCHS 4.1 Introduction iVf k.2 Qualitative Description of Mixing inL.Goil 1^-6 k.3 Water Mixing and Transport ii L.Long 161 k.k Quantitative Analysis of Mixing in L.Goil 166 ^.3 Gareloch and L.Fyne 186 *f.6 General Overview 190 CHAPTER 5. THE HEBRIDEAN SEA AREA 3.1 Introduction 191 5*2 Data for Summer 1976 193 5.3 Data for Summer 1977 20k 5.*f General Conclusions 215 CHAPTER 6 . SEDIMENTS 6.1 Introduction 217 6.2 Coring Methodology 218 6.3 L.Goil - Site 1 23^ 6»k L.Goil - Site 2 and Gareloch 2k9 6.5 Holyloch 253 6.6 Practical Applications and General Results 257 6.7 Summary 260 CHAPTER 7. SYNTHETIC OVERVIEW 7.1 Introduction 263 7.2 Summary of Results 263 137 7*3 Geochemical Budget for Windscale-released Cs 2oo Practical Applications 275 7*5 Further Developments 28*f REFERENCES 286 APPENDICES 30^ APPENDIX I RESULTS TABULATION A1 1.1 Clyde Sea Area A2 1.2 L.Goil/L.Long Deep Sites A7 1.3 Additional Sea Loch Sites Akk I.-k Hebridean Sea Area A59 1*5 Sediment A78 I.6 Miscellaneous A88 APPENDIX II COMPUTER PROGRAMS A92 II.

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