Geothermics and Geothermal Energy

347 Pages·1979·9.123 MB·English

by  J. W. Elder (auth.), Ladislaus Rybach, Lajos Stegena (eds.)

Contributions
to Current Research
in Geophysics (CCRG)
7
Geothermies and
Geothennal Energy
Editors: Ladislaus Rybach
Institute of Geophysies
ETH Zurieh, Switzerland
Lajos Stegena
Eötvös University
Budapest, Hungary
Reprinted from PAGEOPH
1979 Springer Basel AG
Reprinted from Pure and Applied Geophysics
(PAGEOPH),
Volume 117 (1978), Nos 1/2
CIP-Kurztitelaufnahme der Deutschen Bibliothek
Geothermies and geothermal energy: reprinted from
PAGEOPH/ed.: Ladislaus Rybach; Lajos Stegena.
- Basel, Stultgart: Birkhäuser, 1979.
(Contributions to current research in geophysics;
7)
NE: Rybach, Ladislaus [Hrsg.]
All rights reserved. No part of this publication may be reproduced,
stored in a retrieval system, or transmitted, in any form or by
any means, electronic, mechanical, photocopying, recording or
otherwise, without the prior permission of the copyright owner.
© Springer Basel AG, 1979
Originally published by Birkhäuser Verlag Basel in 1979.
Softcover reprint ofthe hardcover 1st edition 1979
ISBN 978-3-0348-6527-2 ISBN 978-3-0348-6525-8 (eBook)
DOI 10.1007/978-3-0348-6525-8
Contents
Editors' Note ............................................................. .
General Geothermics
J. W. ELDER: Magma Traps: Part I, Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
J. W. ELDER: Magma Traps: Part H, Application ................................ 15
ARTHUR H. LACHENBRUCH: Heat Flow in the Basin and Range Province and Thermal
Effects of Tectonic Extension. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
CRAIG S. WEAVER and DAVID P. HILL: Earthquake Swarms and Local Crustal
Spreading Along Major Strike-slip Faults in California . . . . . . . . . . . . . . . . . . . . . . . 51
V. M. HAMZA: Variation of Continental Mantle Heat Flow with Age: Possibility of
Discriminating Between Thermal Models of the Lithosphere . . . . . . . . . . . . . . . . . . 65
LADISLAUS RYBACH: The Relationship Between Seismic Velocity and Radioactive
Heat Production in Crustal Rocks: An Exponential Law . . . . . . . . . . . . . . . . . . . . . . 75
GÜNTER BUNTEBARTH: The Degree of Metamorphism of Organic Matter in Sedimen-
tary Rocks as a Paleo-Geothermometer, Applied to the Upper Rhine Graben 83
Regional H eat Flow
VLADIMtR CERMAK and ECKART HURTIG: The Preliminary Heat Flow Map ofEurope
and Some of its Tectonic and Geophysical Implications ...................... 92
R.I. KUTAS, E.A. LUBIMOVA AND YA.B. SMIRNOV: Heat Flow Map ofthe European
Part ofthe U.S.S.R. . . . . .. . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
JACEK MAJOROWICZ: Mantle Heat Flow and Geotherms for Major Tectonic Units in
Central Europe. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
CRISAN DEMETRESCU: On the Geothermal Regime of Some Tectonic Units in Roma-
~............................................................ IU
M. LODDO and F. MONGELLI: Heat Flow in Italy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
YORAM ECKSTEIN: Review of Heat Flow Data from the Eastern Mediterranean
Re~on ................................................................ ISO
Geothermal Potential
L.J. PATRICK MUFFLER and ROBERT L. CHRISTIANSEN: Geothermal Resource Assess-
ment of the United States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
T.J. LEWIS, A. S. JUDGE and J. G. SOUTHER: Possible Geothermal Resources in the
Coast Plutonic Complex of Southern British Columbia, Canada . . . . . . . . . . . . . . . 172
V.M. HAMZA, S.M. ESTON and R.L.C. ARAUJO: Geothermal Energy Prospects in
Brazil: A Preliminary Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
K.G. ERIKSSON, K. AHLBOM, O. LAND STRÖM, S.A. LARSON, G. LIND and D. MALM-
QVIST: Investigation for Geothermal Energy in Sweden . . . . . . . . . . . . . . . . . . . . . . . 196
NIELS BALLING and SVEND SAXOV: Low Enthalpy Geothermal Energy Resources in
Denmark . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 205
PAUL MORGAN and CHANDLER A. SWANBERG: Heat Flow and the Geothermal Poten-
tial of Egypt ........................................................... 213
Exploration, Characterisation and Exploitation of Geothermal Resources
CHANDLER A. Sw ANBERG and PAUL MORGAN: The Linear Relation Between Tem
peratures Based on the Silica Content of Groundwater and Regional Heat Flow:
A New Heat Flow Map ofthe United States . . . . . . . .. . . . . . . .. . . . . . . . . . . . . . . . 227
INGVAR B. FRIDLEIFSSON: Applied Vo\canology in Geothermal Exploration in Iceland 242
F. D'AMoRE, J. C. SABROUX and P. ZETTWOOG: Determination of Characteristics of
Steam Reservoirs by Radon-222 Measurements in Geothermal Fluids . . . . . . . . . . 253
EMANUEL MAZOR: Noble Gases in a Section across the Vapor Dominated Geothermal
Field of Larderello, Italy ................................................ 262
ALFRED H. TRUESDELL and NANCY L. NEHRING: Gases and Water Isotopes in a Geo-
chemical Section across the Larderello, Italy, Geothermal Field ............... 276
MORTON C. SMITH: Heat Extraction from Hot, Dry, Crustal Rock. . . . . . . . . . . . . . . . . . 290
ALAIN C. GRINGARTEN: Reservoir Lifetime and Heat Recovery Factor in Geothermal
Aquifers used for Urban Heating ......................................... 297
Geothermal Effects of Hydrothermal Circulation
J. W. PRITCHETT and S. K. GARG: Flow in an Aquifer Charged with Hot Water from a
Fault Zone ............................................................ 309
C. H. SONDERGELD and D. L. TURCOTTE: Flow Visualization Studies ofTwo-Phase
Thermal Convection in a Porous Layer .................................... 321
JUN IRIYAMA and Y ASUE ÖKI: Thermal Structure and Energy of (he Hakone Vo\cano,
Japan. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331
Subject Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
Editors' Note
The rapidly growing interest in geothermal energy as an alternative energy source
has raised many basic questions in geothermics. Especially, the contribution of the
various disciplines of earth sciences to the understanding of development and
distribution of geothermal resources, along with various aspects of their utilisation,
became evident. At the 16th IUGG General Assembly 1975 in Grenoble the
International Heat Flow Commission (IHFC) decided to hold a Symposium
'Geothermics and Geothermal Energy', with the aim of clarifying some of these
questions.
The joint General Assembly of the International Associations of Seismology and
Physics ofthe Earth's Interior (JASPEI) and Volcanology and Chemistry ofthe Earth's
Interior (JA VCEI), held in Ourham/England from 9 to 19 August 1977, provided an
international forum for presenting and discussing results of current research in general
and applied geothermics at its Joint Symposium 'Geothermics and Geothermal Energy'
(11-12 August 1977). The Symposium was co-sponsored by the IHFC; its convenors
were the IHFC members L. Stegena and L. Rybach.
The Opening Lecture of the Symposium was delivered by IHFC President E.
Lubimova (USSR): 'On the heat loss of the earth'. Invited papers were given by V.
Cermilk (CSSR) and E. Hurtig (GOR), P. Muffter and R. L. Christiansen (USA) and
M. C. Smith (USA). Session Chairmen were L. Stegena (Hungary), A. Lachenbruch
(USA), F. Evison (New Zealand), G. Pillmason (Iceland) and L. Rybach (Switzerland).
The great number of the presented contributions as weil as the broad international
participation in this Symposium has clearly demonstrated the rapidly growing
importance of geothermics.
This volume contains the papers presented at the Symposium 'Geothermics and
Geothermal Energy' with a few modifications. The following papers were given in
Ourham but are not included in this issue (for various reasons, e.g. no manuscripts
submitted or published elsewhere):
E. E. OAVIS, C. R. B. LISTER and U. S. WADE (USA): Oetailed he at flow
measurements in faul ted and unfaulted young oceanic crust.
S. W. RICHARDSON and P. C. ENGLAND (UK): Age dependence of continental heat
flow.
M. H. OODSON (UK): A model for terrestrial convection.
F. HORVÄTH, L. BODRI and L. STEGENA (Hungary): The heat anomaly of the
Pannonian Basin and its tectonophysical background.
W. A. ELDERS (USA): Physical effects of water/rock reactions in evolving
geothermal systems.
P. L. ERNST (FRG): Exploitation of geothermal energy in Germany.
M. L. GUPTA (India): Heat flow distribution and possibilities of exploiting
geothermal energy in India.
M. TONELLI (ltaly): Airborne and space geothermics.
2
H. M. IYER and T. HITCHCOCK (USA): Use of seismic noise and P-wave delays in
geothermal exploration.
R. ALVAREZ (Mexico): Telluric detection of geothermal areas.
J. R. BLOOMER (UK): Thermal conductivity ofMesozoic mudstones from Southern
England.
D. S. CHAPMAN, F. H. BROWN, K. L. COOK, W. P. NASH, W. T. PARRY, W. R. SILL,
R. B. SMITH, S. H. WARD and J. A. WHELAN (USA): Roosevelt Hot Springs
Utah: a Basin and Range geothermal system.
F. F. EVISON (New Zealand): The downflow regime in natural hydro-thermal
systems.
On the other hand, the present volume contains several papers which were scheduled
for presentation at the Durharn Meeting but could not be given there for various
reasons.
In these Proceedings the contributions of the Symposium ha ve been arranged in the
following order: (i) General Geothermics, (ii) Regional Heat Flow, (iii) Geothermal
Potential, (iv) Exploration, Characterisation and Exploitation of Geothermal
Resources, (v) Geothermal Effects of Hydrothermal Circulation. In editing the
Proceedings an attempt was made to use SI units throughout. This goal has nearly been
achieved; at least both units are given, particularly in the figures. The kind cooperation
of numerous colleagues who acted as reviewers is gratefully acknowledged.
Sincere thanks are due to Dr. R. E. Long, Organizing Secretary of the
IASPEI/IA VCEI General Assembly (Department of Geological Sciences, Durharn
University) for providing an ideal infrastructure for the Symposium. The participants
departed with the feeling of not only having discussed data and results but also having
gained deeper insight into the manifold interrelations of geothermics and geothermal
energy.
Budapest and Zurich, July 1978
L. STEGENA
L. RYBACH
Pageoph, Vol. 117 (1978/79), Birkhäuser Verlag, Basel
Magma Traps: Part I, Theory
Abstract - The role ofthe buoyancy barrier ofthe stratified crust in controlling the ascent ofmagmas
is represented bya model which operates dose to lithostatic equilibrium and in which fractional crystalliza
tion ofthe magma or partial melting ofthe ambient rock can occur. The density structure ofthe crust has a
powerful effect in trapping magma and thereby in controlling the occurrence of high level geothermal
systems. The model is tested in Part II (this volume).
Key words: Ascent of magma; Lithostatic equilibrium; Oceanic and continental crust; Density of
magma.
1. Introduction
For the heat flowing from the interior of the earth to be most readily available
for use by high-level geological systems or human exploitation it needs to be retained
temporarily in a high-level reservoir. Perhaps the simplest systems of this kind are
deep sedimentary basins which are heated by nonnal near surface conductive heat
flow. A good example is the Pannonian basin of eastern Europe. The behaviour of
these rather passive systems are weil understood. Such is not the case for active systems
related to contemporary volcanism. Strong geothennal activity, as found in modern
hydrothennal systems, is undoubtedly related to ambient volcanism. Yet it is curious
that often only minor parasitic hydrothennal systems are directly associated with
active volcanic systems. This leads us to consider the very simple idea that in such
systems the bulk of the energy has been dissipated at the surface and to raise the
question of under what circumstances a magmatic system can retain part or all of its
energy at depth. We are lead to the notion of geothennal or magma traps.
Where a volume of magma is trapped below the surface in a zone sufficiently
penneable and with access to surface and connate waters, a hydrothennal system
can develop. I have presented elsewhere an outline of the processes involved (ELDER,
1977).
A variety of trapping mechanisms have already been identified. Trapping can
occur at quite deep levels simply because the rising magma volume freezes - and
certain granitic systems, because of the chemical buffering of water, are especially
I) Geology Department, Manchester University, Manchester MI3 9PL, England.
4 J. W. EIder (Pageoph,
prone to this (HARRIS et al., 1970). Trapping ean oeeur at high levels in many ways,
a notable example being in Reeent subglaeial voleanism of Iceland beeause of the
enhaneed porosity and permeability ofthe deposits (for example: FRIDLEIFSSON,1976).
In this study, however, I wish to draw attention to what is perhaps the simplest
trapping meehanism of all - namely th~ statie effeets of the ambient stratified erust
and mantle on the magma eolumn. The key idea is not new, and it has been used by
several authors (for example: HOLMES, 1965; RAMBERG, 1963 - esp. pp. 53ff;
MODRINIAK and STUDT, 1959). As far as I am aware, its testing against data frbm the
eentral West Greenland U pper Cretaeeous - Lower Tertiary sedimentary and volcanic
area, deseribed in Part 11 (this volume), is the most detailed study to date.
The study is incomplete in so far as purely statie constraints are imposed on the
model. The next step would be a study of reservoir dynamics.
2. Lithostatie eontrols ofvoleanism
Consider those aspeets of lithothermal systems which are meehanically eontrolled
by variations of the ambient erust. The emphasis is not so mueh on the magma but
on the gross features of its container. For the want of a word I refer to lithostatics.
In this and subsequent seetions we calibrate these ideas by discussion of partieular
systems.
If the solid earth were a homogeneous body, production of a sufficiently volumi
nous partially molten region at depth would always lead to a surface discharge, sinee
the magma density being less that of its solid parent, the magma column, even if it
reached the surface would have less weight than a similar body of solid rock. But all
magmas do not reach the surface. This is simply because the erust is stratified, with
material near the surface not only less dense than that at depth but is also less dense
than some magmas. For these magmas the uppermost layers of the earth present a
buoyancy barrier whichean be penetrated or punctured only under special
cireumstanees.
Manometrie model
The key idea used in the quantitative diseussion is the notion of lithostatic equi
librium. Isostatic readjustments are geologically very rapid, with a time scale of
order 104 yr (HASKELL, 1937). Lithostatic models of erustal and upper mantle systems
with time scales greater than 104 yr provide therefore good approximations to the
overall distribution of mass. All the models below treat the system under discussion
as if it were a simple manometer eonstructed from two verticallimbs - for example,
one limb may be the unchanged crust the other limb the thinned crust. The essence
of the calculations is that since the manometer is elose to static equilibrium, equating
the two pressures at the base of eaeh limb is sufficient to determine the situation.
Vol. 117.1978/79) Magma Traps. Theory 5
The structure of a volcanic system will also be treated as a manometer operating
dose to static equilibrium. Clearly the lava pile will continue to grow locally until
it reaches static equilibrium. Only this terminal or equilibrium state is used here for
the identifkation of the volcanic manometer.
Rearrangement of the crust and upper mantle occurs on a time scale of order
100 M yr. Hence volcanic systems can be regarded in the gross aspects oftheir behaviour
as quasi-steady systems embedded in an ambient system which is slowly changing.
Although the volcanic system remains dose to equilibrium this does not imply that
it also necessarily changes slowly - as we shall see below.
Crusla/ /ayers
Consider a layered crust as sketched in Fig. I made up of a stack of layers of
thickness hi and density Pi where, counting the layers downwards 0 to n + 1: layer 0
Thinned crust Unthinned crust
J,L
-J,
w .T-
msl ...
0: ocean -'" f
1 : sediments
H
2: upper crust upper crust 2
3 : lower crust
H
lower crust 3
l'
4: mantle v 1
,1.
Figure 1
Sehematie representation of the erust.
represents the ocean; layer n + I represents the deepest layer of interest, part of the
mantle. If a layer is absent, we simply set its corresponding thickness to zero. Here
only the following are considered, with 11 = 3:
O. the ocean of density 1.03 gjcm3, taken as I gjcm3 in all calculations;
I. unconsolidated sediments of density 2.5 gjcm 3;
2. upper crust of c~nsolidated sediments and gneissic basement of density 2.7 gjcm3;
3. lower erust to density 3.0 gjcm 3, gravitationally indistinguishable from basalt;
4. mantle ofdensity 3.3 gjcm3.
Rejerence crusl. It is particularly useful to have a standard or referenee erust. This
can be used as the basis of a variety of models. Although the choice is somewhat