BACHELOR THESIS Some hydrographical changes in the Sognefjord and its tributaries, the Sogndalsfjord and the Barsnesfjord (Western Norway), the last century by 126 Theresa Reβ Bachelor Work in Geology Subject Code: GE-491 Date of Submission: 10.06.2015 Agreement regarding the electronical deposit of scientific publications in HiSF Brage – Institutional archive of Sogn og Fjordane University College The author(s) hereby give(s) Sogn og Fjordane University College the right to make this thesis available in HiSF Brage provided that the thesis is awarded grade B or better. I guarantee that I - together with possible co-authors - have the right of authorship to the material thus have legal rights to allow HiSF to publish the material in Brage. I guarantee that I have no knowledge or suspicion indicating that this material is illegal according to Norwegian law. Please fill in your candidate number and name below and tick off the appropriate answer: Candidate number and name YES ___ NO___ Candidate number and name YES ___ NO___ Candidate Number and name YES ___ NO___ I Eingereicht am: Angenommen am: Von: Bingen, den Betreuer (FH): Prof. Dr. Elke Hietel Betreuer (extern): Prof. Torbjørn Dale Associated Prof. Dr. Matthias Paetzel II Declaration of Academic Honesty: Hereby I affirm that the submitted work “Some hydrographical changes in the Sognefjord and its tributaries the Sogndalsfjord and the Barsnesfjord (Western Norway), the last century” has been completed by me autonomously and without outside help. I thereby neither used other than the stated reference sources or materials, nor perpetrated I any other form of plagiarism. Furthermore I declare that the work has not been published in an equal or similar way before and has not been submitted for any other purposes before. Eidesstattliche Erklärung: Hiermit erkläre ich an Eides statt, dass ich die vorliegende Bachelorarbeit “Hydrographische Veränderungen im Sognefjord und seinen Seitenarmen, dem Sogndalsfjord und dem Barsnesfjord (West Norwegen), im letzten Jahrhundert” Selbstständig und ohne fremde Hilfe angefertigt habe. Ich habe dabei nur die in der Arbeit angegebenen Quellen und Hilfsmittel benutzt. Die Arbeit wurde in gleicher oder ähnlicher Form noch keiner anderen Prüfung vorgelegt und auch noch nicht veröffentlicht. (Place, Date) (Signature) III Table of Contents Abstract ................................................................................................................................... VI Acknowledgement ................................................................................................................. VII 1. Introduction ..................................................................................................................... 1 1.1 General background ..................................................................................................... 1 1.2 Objectives ..................................................................................................................... 1 1.2.1 Explanation Objective 1 .................................................................................... 2 1.2.2 Explanation Objective 2 .................................................................................... 3 1.2.3 Explanation Objective 3 .................................................................................... 3 1.2.4 Explanation Objective 4 .................................................................................... 3 1.2.5 Explanation Objective 5 ................................................................................... 4 1.3 Setting .......................................................................................................................... 4 1.3.1 Fjords ................................................................................................................ 4 1.3.2 Geography ........................................................................................................ 9 1.3.3 Historical setting ............................................................................................. 16 1.3.4 Climate setting ................................................................................................ 22 2. Materials and Methods ................................................................................................. 26 2.1 The Barsnesfjord and Sogndalsfjord .......................................................................... 28 2.2 The Sognefjord and Sognesjøen ................................................................................. 29 2.3 The Nordic Sea and Station Mike ............................................................................... 30 2.4 Characteristics of the various data and some assumptions....................................... 30 3. Results ........................................................................................................................... 32 3.1 Climate ....................................................................................................................... 32 3.1.1 Precipitation ................................................................................................... 32 3.1.2 Temperature .................................................................................................. 36 3.2 Hydrography Outer Barsnesfjord ................................................................................. 40 3.2.1 Salinity ............................................................................................................ 40 3.2.2 Temperature .................................................................................................. 44 3.3 Sognalsfjord ................................................................................................................ 49 3.3.1 Salinity ............................................................................................................ 49 3.3.2 Temperature .................................................................................................. 53 3.3 Sognesjøen ................................................................................................................. 58 3.3.1 Salinity ............................................................................................................ 58 3.3.2 Temperature .................................................................................................. 64 IV 3.4 Station Mike ............................................................................................................... 70 3.4.1 Salinity ............................................................................................................ 70 3.4.2 Temperature .................................................................................................. 76 4. Discussion ...................................................................................................................... 82 4.1 Discussion Objective 1................................................................................................ 82 4.1.1 Discussion ....................................................................................................... 82 4.1.2 Conclusion....................................................................................................... 83 4.2 Discussion Objective 2................................................................................................ 83 4.2.1 Discussion ....................................................................................................... 83 4.2.2 Conclusion ....................................................................................................... 84 4.3 Discussion Objective 3 ............................................................................................... 85 4.3.1 Outer Barsnesfjord ......................................................................................... 85 4.3.2 Sogndalsfjord .................................................................................................. 87 4.3.3 Sognesjøen ..................................................................................................... 88 4.3.4 Conclusion ...................................................................................................... 89 4.4 Discussion Objective 4................................................................................................ 90 4.4.1 Outer Barsnesfjord ......................................................................................... 90 4.4.2 Sogndalsfjord .................................................................................................. 93 4.4.3 Sognesjøen ..................................................................................................... 95 4.4.4 Nordic Sea ...................................................................................................... 98 4.4.5 Conclusion .................................................................................................... 102 4.5 Discussion Objective 5 ............................................................................................... 102 4.5.1 Discussion ..................................................................................................... 102 4.5.2 Conclusion .................................................................................................... 109 4.5.3 Possible biological consequences of hydrographic changes ....................... 113 5. Conclusion ..................................................................................................................