Iceland Within the Northern Atlantic, Volume 2: Interactions between Volcanoes and Glaciers

256 Pages·2021·103.29 MB·English

by  Brigitte Van Vliet-Lanoe

Iceland Within the Northern Atlantic 2
SCIENCES
Geoscience, Field Director – Yves Lagabrielle
Lithosphere-Asthenosphere Interactions, Subject Head – René Maury
Iceland Within the
Northern Atlantic 2
Interactions between
Volcanoes and Glaciers
Coordinated by
Brigitte Van Vliet-Lanoë
First published 2021 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc.
Apart from any fair dealing for the purposes of research or private study, or criticism or review, as
permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced,
stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers,
or in the case of reprographic reproduction in accordance with the terms and licenses issued by the
CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the
undermentioned address:
ISTE Ltd John Wiley & Sons, Inc.
27-37 St George’s Road 111 River Street
London SW19 4EU Hoboken, NJ 07030
UK USA
www.iste.co.uk www.wiley.com

© ISTE Ltd 2021
The rights of Brigitte Van Vliet-Lanoë to be identified as the author of this work have been asserted by
her in accordance with the Copyright, Designs and Patents Act 1988.
Library of Congress Control Number: 2021934743

British Library Cataloguing-in-Publication Data
A CIP record for this book is available from the British Library
ISBN 978-1-78945-015-6
ERC code:
PE10 Earth System Science
PE10_5 Geology, tectonics, volcanology
PE10_13 Physical geography
PE10_18 Cryosphere, dynamics of snow and ice cover, sea ice, permafrosts and ice sheets
Contents
List of Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv
Brigitte VAN VLIET-LANOË and Françoise BERGERAT
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix
Brigitte VAN VLIET-LANOË and René MAURY
Chapter 1. Young Icelandic Volcanism and its Implications . . . . . 1
René MAURY and Brigitte VAN VLIET-LANOË
1.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2. Icelandic magma series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2.1. Lava types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2.2. Geochemical diversity of young Icelandic basalts
and their sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.2.3. Some geochemical constraints concerning the origin
and geodynamic evolution of Iceland . . . . . . . . . . . . . . . . . . . . . 13
1.3. Central volcanoes and active fissural systems . . . . . . . . . . . . . . . 14
1.3.1. Central volcanoes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1.3.2. Fissural volcanism and subaerial lava flows . . . . . . . . . . . . . 17
1.3.3. Hydromagmatism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
1.4. Volcanic hazards in Iceland . . . . . . . . . . . . . . . . . . . . . . . . . . 31
1.4.1. Hazards related to lava flows . . . . . . . . . . . . . . . . . . . . . . 31
vi Iceland Within the Northern Atlantic 2
1.4.2. Hazards related to explosions and gas emissions . . . . . . . . . . 32
1.4.3. Jökulhlaups and associated hazards . . . . . . . . . . . . . . . . . . 37
1.4.4. Icelandic dust: a consequence of volcanism . . . . . . . . . . . . . 44
1.5. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Chapter 2. Volcanism and Glaciations: Forcings and
Chronometers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Hervé GUILLOU, René MAURY and Brigitte VAN VLIET-LANOË
2.1. Subglacial volcanic landforms . . . . . . . . . . . . . . . . . . . . . . . . . 57
2.1.1. Subglacial isolated volcanoes or tuyas . . . . . . . . . . . . . . . . 58
2.1.2. Hyaloclastite ridges or tindar . . . . . . . . . . . . . . . . . . . . . . 61
2.2. Volcanism, deglaciation and climate . . . . . . . . . . . . . . . . . . . . . 65
2.2.1. General features: deglaciation, discharge and partial
melting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
2.2.2. Deglaciation and climate feedback . . . . . . . . . . . . . . . . . . . 69
2.3. The hypothesis of a link between volcanism and climate
and its test by dating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
2.3.1. The K-Ar chronometer . . . . . . . . . . . . . . . . . . . . . . . . . . 71
2.3.2. The combination of K-Ar and 40Ar/39Ar methods
for dating Icelandic volcanism . . . . . . . . . . . . . . . . . . . . . . . . . 80
2.3.3. A link between volcanism and climate according to
K-Ar ages? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
2.3.4. A rhyolitic volcanism synchronous with deglaciations? . . . . . . 88
2.4. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Chapter 3. Cenozoic Evolution of Iceland and the
Cryosphere . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Brigitte VAN VLIET-LANOË and Hervé GUILLOU
3.1. Ice ages and the opening of the Atlantic . . . . . . . . . . . . . . . . . . . 103
3.1.1. The Middle and Final Miocene cooling . . . . . . . . . . . . . . . . 108
3.1.2. The acceleration of the Middle Pliocene . . . . . . . . . . . . . . . 109
3.1.3. The Middle Pleistocene Transition . . . . . . . . . . . . . . . . . . . 112
3.1.4. The initiation of thermohaline circulation . . . . . . . . . . . . . . . 114
3.2. Iceland’s Quaternary glaciations . . . . . . . . . . . . . . . . . . . . . . . 116
3.2.1. Conditions for the development and functioning
of ice caps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
3.2.2. Glacio-isostasy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
3.2.3. Icelandic data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
3.2.4. The Icelandic record . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Contents vii
3.3. The last glacial episode and its deglaciation . . . . . . . . . . . . . . . . 142
3.3.1. The Weichselian . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
3.3.2. The Last Glacial Maximum . . . . . . . . . . . . . . . . . . . . . . . 144
3.3.3. Deglaciation and the Holocene . . . . . . . . . . . . . . . . . . . . . 150
3.4. Iceland today, its climate and vegetation . . . . . . . . . . . . . . . . . . 161
3.4.1. The climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
3.4.2. Ocean circulation and climate . . . . . . . . . . . . . . . . . . . . . . 162
3.4.3. Soil, people and climate . . . . . . . . . . . . . . . . . . . . . . . . . 167
3.4.4. Soils and erosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
3.5. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
Brigitte VAN VLIET-LANOË, René MAURY and Hervé GUILLOU
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
List of Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
Summary of Volume 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
List of Abbreviations
σ , σ and σ Maximum, intermediate and minimum principal stresses of the
1 2 3
stress tensor
σ Maximum horizontal stress
Hmax
A
AMO Atlantic multidecadal oscillation
B
BTVP British Tertiary Volcanic Province
C
CGFZ Charlie–Gibbs Fracture Zone
CGPS Communicative Global Positioning System
D
DL Dalvik Line
DMM Depleted MORB mantle
DO Dansgaard–Oeschger event
Iceland Within the Northern Atlantic 2,
coordinated by Brigitte VAN VLIET-LANOË. © ISTE Ltd 2021.
x Iceland Within the Northern Atlantic 2
DSOW Denmark Strait overflow water
DTM Digital terrain model
E
E-MORB Enriched mid-ocean ridge basalts
EM Enriched mantle
EUR Europe
EVZ East Volcanic Zone
F
FLF Flat-lying flows
G
GEBCO General Bathymetric Chart of the Oceans
GIA Glacio-isostatic adjustment
GIFR Greenland–Iceland–Faroe Ridge
GIR Greenland–Iceland Ridge
GL Grimsey Line
GPS Global Positioning System
H
HFF Húsavík-Flatey Fault
HIMU High Mu mantle (Mu = U/Pb)
List of Abbreviations xi
I
ICPMS Inductively coupled plasma mass spectrometry
IFR Iceland–Faroe Ridge
IGS International GPS Service
IMO Icelandic Meteorological Office (Veðurstofa Íslands)
InSAR Interferometric Synthetic Aperture Radar
IRD Ice-rafted detritus
ISOW Iceland–Scotland Overflow Water
ÍSNET GPS Network surveys of the National Land Survey of Iceland
(Landmælingar Íslands)
J
JMFZ Jan Mayen Fracture Zone
K
KR Kolbeinsey Ridge
L
LBA Labrador–Baffin axis
LGM Last Glacial Maximum (extension)
LIP Large igneous provinces
M
M or M Moment magnitude
W
MAR Mid-Atlantic Ridge