Climate, Earth Processes and Earth History

287 Pages·1991·10.61 MB·English

by  Dr. Richard John Huggett (auth.)

Richard John Huggett
Climate,
Earth Processes and
Earth History
With 71 Figures
Springer-Verlag
Berlin Heidelberg New York
London Paris Tokyo
Hong Kong Barcelona
Budapest
Dr. RICHARD JOHN HUGGETT
University of Manchester
School of Geography
Manchester, M13 9PL
England
ISBN-13: 978-3-642-76270-3 e-ISBN-13: 978-3-642-76268-0
DOl: 10.1007/978-3-642-76268-0
Library of Congress Cataloging-in-Publication Data. Huggett, Richard J. Climate, earth processes,
and earth history / Richard John Huggett. p. cm. Includes bibliographical references. 1.
Climatology. 2. Paleoclimatology. 3. Biosphere. I. Title. QC981.H84 1991 551.6-dc20 91-23129
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© Springer-Verlag Berlin Heidelberg 1991
Softcover reprint of the hardcover 1s t edition 1991
The use of general descriptive names, registered names, trademarks, etc. in this publication does
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Typesetting: International lYpesetters Inc., Makati, Philippines
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For Shelley and Zoe
Foreword
Today, climate-related processes and problems are referred to as
Global Change by nearly everyone including scientists, politicians,
and economists; citizens worldwide are anxious about the often ob
served disorientation of our environment under the influence of man.
Better information on the Earth's natural systems and their possible
alterations is necessary. The topic itself is so wide that sound scien
tific descriptions of it as a whole are rare. For the non-specialist infor
mation from relevant fields is not easy to obtain; and often, the pro
gnostic models presented are contradictory and even for specialists
difficult to evaluate. Therefore, this book on Climate, Earth Processes
and Earth History by Richard Huggett fills an important gap. It
discusses the great, climate-related areas of the Earth's environment.
The atmosphere, the hydrosphere, the sediments as products of
weathering and geomorphic processes, the relief as landforms and
soils, and the biosphere are thoroughly treated as the prominent sub
systems which are greatly affected by climate. These subsystems not
only control the visual and internal aspects of our landscapes, but
they are themselves especially influenced by climatic changes which
can be due to either changes in the natural system or anthropogenic
changes. Thus, our landscapes will be subject to significant altera
tions, if climatic variations exceed certain thresholds.
The plan for the present book by Richard Huggett was originally
discussed in regard to the Springer Series on Physical Environment.
Soon, it became clear that it should be directed towards a broader au
dience and not only to specialists. Therefore, it is not published as
part of the series, in the hope that a wider audience will be reached.
The book will help to further our understanding of our physical envi
ronment and the climate-related changes which may occur in the
years to come.
Dietrich Barsch
Preface
Our knowledge and understanding of the workings of the world
climate system has taken a quantum leap in the last couple of
decades. The reasons for this lie partly in the building of
sophisticated climate models for computers, partly in the vast
amounts of data sensed by satellites, and partly in the establishment
of a reliable calendar of geological events. This book shows how the
great strides being made in climatology and palaeoclimatology are
leading to fresh insights into the interaction between the atmosphere
and other parts of the biosphere (animals, plants, sediments, soils,
and landforms), and to a new view of the relations between the at
mosphere and other Earth systems - a view in which climatic control
is seen as both more profound and yet more subtle than was previous
ly thought.
After introducing the concept of the world climate system, the
book explores the chief components of the biosphere - air, ice and
water, sediments, landforms and soils, animals and plants, and
biomes and zonobiomes - in relation to climatic factors. For each
component, a thumbnail sketch of the historical development of ideas
on the role played by climate is provided. Some readers may be sur
prised to discover the antiquity of many, supposedly new-fangled, hy
potheses. A concluding chapter moves towards a synthesis of the
preceding material. It opens by developing a general model of the
biosphere and then, in the context of the model, discusses two key
ideas arising from the material in the earlier chapters, namely, the
question of scale and the origin of cyclicity within the biosphere.
The subject matter of the book being so broad, it would have been
easy to pen a tome of Brobdingnagian proportions. Keeping to a
modest wordage has required a ruthless and somewhat invidious
selecting of topics and examples, as well as swingeing excisions of en
tire sections from earlier drafts. The result is a book which focusses
on the interactions of Earth surface systems with climate at regional
and global levels of interest. Even under that more closely cir
cumscribed rubric, it was not possible to include all fields of enquiry.
Topics included were chosen for their currency and for their being
x Preface
familiar to the author. They are, however, diverse enough to cater for
a wide audience. A theme which runs through the topics is the im
measurable value of an interdisciplinary approach to the study of the
world climate system (biosphere). The book will have served a useful
purpose if it alerts specialists who delve into fairly narrow aspects of
climatic connexions - be they biologists, ecologists, environmental
scientists, geographers, geomorphologists, or geologists - to devel
opments in fields other than their own and to more general issues
which cross the artificial divides of geoscientific disciplines.
I should like to thank several people for helping with the produc
tion of the book: for continued faith in my unfashionable style of
research, Ian Douglas; for drawing the figures, Graham Bowden (who
had a little assistance from Nick Scarle); for smoothing the process
of production, the editorial staff at Springer's Heidelberg Office; for
acting as guinea-pigs for much of the material presented in the book,
all students who were brave enough to opt for my third-year course
on the Biogeography and Geomorphology of the Continents; and, as
ever, for constant patience and support, my wife Shelley.
Poynton, June 1991 Richard Huggett
Contents
1 Introduction ....................................... .
1.1 From Thermometers to Satellites ..................... 1
1.2 The World Climate System .......................... 4
1.3 Climatic Change ................................... 6
1.4 Scales of Systems .................................. 9
2 Air ........................ ........ .. ..... .......... 13
2.1 Solar Forcing ...................................... 13
2.1.1 Cycles of Solar Activity ....................... 13
2.1.2 Solar Signals in the Atmosphere ................ 14
2.1.3 Mechanisms of Short-Term Solar Forcing ........ 17
2.1.4 Longer-Term Variations in Solar Activity ......... 18
2.2 Short-Term Gravitational Forcing ..................... 20
2.2.1 Lunar Signals ................................ 20
2.2.2 Short-Term Orbital Forcing ..................... 21
2.2.3 Short-Term Changes in the Earth's Spin Rate ..... 23
2.3 Medium-Term Gravitational Forcing .................. 23
2.3.1 Ellipticity, Precession, and Obliquity ............ 23
2.3.2 Problems with the Croll-Milankovitch Theory .... 26
2.4 Internal Dynamics of the Climate System ............. 30
2.4.1 Carbon Dioxide .............................. 30
2.4.2 Methane and Dust ............................ 34
2.5 Geophysical Forcing ................................ 35
2.5.1 Volcanoes .................................... 35
2.5.2 Vapour Plumes and Meteoritic Dust . . . . . . . . . . . . . 37
2.5.3 Relief ....................................... 39
2.5.4 The Arrangement of Land and Sea ............. 41
2.5.5 Geothermal Energy ........................... 42
2.5.6 True Polar Wander ............................ 43
2.5.7 The Earth's Rotation Rate ..................... 44
2.5.8 Large Changes of Obliquity .................... 46
XII Contents
3 Ice and Water .................................. . . . . . 49
3.1 Terrestrial Systems and the Water Cycle. . . . . . . . . . . . . . . 49
3.1.1 Descriptive Approaches ........................ 49
3.1.2 Energetic Approaches ......................... 52
3.1.3 Hydrological Models .......................... 54
3.2 Short-Thrm Changes in the Hydrosphere .............. 55
3.2.1 Droughts, Floods, and the Lunar Cycle .......... 55
3.2.2 Volcanoes and the Cryosphere .................. 56
3.3 Medium-Term Changes in the Hydrosphere ............ 57
3.3.1 Monsoons ................................... 58
3.3.2 Soil Moisture. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
3.3.3 Lakes ....................................... 61
3.3.4 Glacio-Eustatic Changes ....................... 67
3.4 Long-Term Changes in the Hydrosphere.. . . . . .. . .. . .. . 68
3.4.1 Ancient Water Budgets ........................ 68
3.4.2 Ice Ages Through Earth History ................ 70
4 Sediments .......................................... 77
4.1 Weathering ........................................ 77
4.1.1 Weathering and Climate ....................... 77
4.1.2 Weathering and Leaching Regimes .............. 78
4.2 Denudation and Deposition ......................... 83
4.2.1 Mechanical Denudation . . . . . . . . . . . . . . . . . . . . . . . . 84
4.2.2 Chemical Denudation ......................... 88
4.2.3 Slope Processes ............................... 91
4.2.4 Regional and Global Patterns of Denudation ..... 93
4.3 Short-Term Forcing of Denudation-Deposition Systems. . 94
4.3.1 Solar Signals in Sediments ..................... 94
4.3.2 Lunar Signals in Sediments .................... 95
4.4 Medium-Term Forcing of Denudation-Deposition
Systems ...... ,. . ............................ ...... 96
4.4.1 Thrrestrial Deposits ............... . . . . . . . . . . . . . 96
4.4.2 Marine Deposits .............................. 98
4.4.3 Lake and Evaporite Deposits ................... 103
4.5 Long-Term Changes in Sediments .................... 104
4.5.1 Palaeoclimatic Significance of Palaeosols ........ 104
4.5.2 Glacial Deposits in the Tropics ................. 108
5 Landforms and Soils ................................ 111
5.1 Soils and Climate .................................. 111
5.1.1 The Climatic Factor in Soil Formation .......... 111
5.1.2 Soil Types and Climate ........................ 113
5.1.3 Soil Processes and Climate. . . . . . . . . . . .. . . . . . . . . 115
5.2 Landscape Morphometry and Climate ................ 121
Contents XIII
5.2.1 Morphoclimatic Regions ....................... 121
5.2.2 Morphometry and Climate. . . . .. . . . . . .. . . . . . . . . 125
5.2.3 The Origin of Asymmetrical Valleys ............. 130
5.3 Landforms and Soils During the Pleistogene Period .... 132
5.3.1 Soil-Landscape Change and Glacial-Interglacial
Cycles ....................................... 133
5.3.2 Soil Landscapes and Climatic Change During the
Holocene Epoch .............................. 137
5.3.3 Modelling the Response of Hillslope Form to
Climatic Change. . .. . . . . . . . . . . . . . . . . . . . . . . . . . . 139
5.4 Pre-Pleistogene Soil-Landscape History ............... 145
6 Animals and Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
6.1 Climatic Influences on Life ......................... 149
6.1.1 Plants ....................................... 149
6.1.2 Animals ..................................... 152
6.2 Biogeographical Regularities ......................... 152
6.2.1 Ecogeographical Rules ......................... 153
6.2.2 Climatic Interpretations of Ecogeographical Rules 155
6.2.3 Modern Studies of Bergmann's Rule ............ 156
6.3 Patterns of Species Richness and Climate ............. 158
6.3.1 The Species-Energy Theory .................... 158
6.3.2 Species Richness in North America ............. 159
6.4 Short-Term Climatic Change and Organisms. . . . . . . . . . . 164
6.4.1 Animals, Plants, and Solar Cycles .............. 164
6.4.2 Animals, Plants, Volcanoes, and Meteorites ...... 166
6.5 Medium-Term Climatic Change and Organisms ........ 167
6.5.1 Bergmann's Rule and Holocene Faunas .......... 167
6.5.2 Pleistocene Extinctions and Extirpations ......... 168
7 Biomes and Zonobiomes ............................. 175
7.1 The Coming of Ecology ............................ 175
7.2 Communities and Climate .......................... 177
7.2.1 Life Zones ................................... 177
7.2.2 Vegetation and Temperature .................... 177
7.2.3 Communities as Dynamic Continua ............. 181
7.2.4 Plant Physiognomy and Climate: a Predictive
Model....................................... 183
7.2.5 Plant Productivity and Climate ................. 186
7.2.6 Plants and the Biosphere: Model Interactions .... 190
7.3 Medium-Term Climatic Swings and Plant Communities. 192
7.3.1 The Response of Vegetation to Deglaciation ...... 192
7.3.2 The Response of Vegetation to Glacial-Interglacial
Cycles....................................... 196