Enhanced: Earthquakes Cannot Be Predicted
Robert J. Geller, David D. Jackson, Yan Y. Kagan, Francesco
R. J. Geller [HN1]
is at the Department of Earth and Planetary Physics, Faculty of
Science, Tokyo University, Yayoi 2-11-16, Bunkyo-ku, Tokyo 113,
D. D. Jackson and Y. Y. Kagan [HN2-3]
are at the Department of Earth and Space Sciences, University of
California, Los Angeles, CA 90095-1567, USA. E-mail:email@example.com and firstname.lastname@example.org. F. Mulargia [HN4]
is at the Dipartimento di Fisica, Settore di Geofisica, Universita
di Bologna, Viale Berti Pichat 8, 40127 Bologna, Italy.
Earthquake prediction [HN5-7]
is usually defined as the specification of the time, location, and
of a future earthquake within stated limits. Prediction would have
to be reliable (few false alarms and few
failures) and accurate (small ranges of uncertainty in space, time,
and magnitude) to justify the cost of response. Previous
Perspectives inScience may have given a favorable
impression of prediction research, and the news media and some
optimistic scientists encourage the belief that earthquakes can be predicted (1).
Recent research suggests to us that this belief is incorrect.
An earthquake results from sudden slip on a geological fault. [HN10]
Such fracture and failure [HN11-13]
problems are notoriously intractable. The heterogeneous state of the
Earth and the inaccessibility of the fault zone to direct
measurement impose further difficulties. Except during a brief
period in the 1970s (2),
the leading seismological authorities of each era have generally
concluded that earthquake prediction is not feasible (3).
developer of the eponymous magnitude scale, commented as follows in
1977: "Journalists and the general public rush to any suggestion of
earthquake prediction like hogs toward a full trough... [Prediction]
provides a happy hunting ground for amateurs, cranks, and outright
publicity-seeking fakers" (4).
This comment still holds true.
For large earthquakes to be predictable, they would have to
be unusual events resulting from
specific physical states. However, the consensus of a recent meeting
was that the Earth is in a state of self-organized criticality [HN16]
where any small earthquake has some probability of cascading into a
large event. This view is supported by the observation that the
distribution of earthquake size (see figure) is invariant [HN17]
with respect to scale for all but the largest earthquakes. Such scale invariance is
ubiquitous in self-organized critical systems (6).
Whether any particular small earthquake grows into a large
earthquake depends on a myriad of fine details of physical
conditions throughout a large volume, not just in the immediate
vicinity of the fault (7).
This highly sensitive nonlinear dependence of earthquake rupture on
unknown initial conditions severely limits predictability (8,9).
The prediction of individual large earthquakes would require the unlikely
capability of knowing all of these details with great accuracy.
Furthermore, no quantitative theory for analyzing these data to
issue predictions exists at present. Thus, the consensus of the
meeting was that individual earthquakes are probably inherently
quakes. Number of earthquakes from 1 January 1977 to 30
June 1996 in the Harvard catalog [HN27]
with magnitude greater thanM for shallow (0 to 70 km),
intermediate (71 to 300 km), and deep (301 to 700 km) earthquakes. Dotted lines are
power-law curves modified by an exponential taper for the largest
magnitudes [equation 3 of (8)].
Analyses of smaller earthquakes show that self-similarity
extends to magnitudes as small as zero (25).
Such power-law curves are characteristic of systems in a state of
Empirical earthquake prediction would require the existence of
observable and identifiable precursors [HN18]
that would allow alarms to be issued with high reliability and
accuracy. There are strong reasons to doubt that such precursors
Thousands of observations of allegedly anomalous phenomena
(seismological, geodetic, hydrological, geochemical,
electromagnetic, animal behavior, and so forth) have
been claimed as earthquake precursors,
but in general, the phenomena were claimed as precursors only after
the earthquakes occurred. The pattern of
alleged precursors tends to vary greatly from one earthquake to the
next, and the alleged anomalies are frequently observed at only one
point, rather than throughout the epicentral region. There are no
objective definitions of "anomalies," no quantitative physical
mechanism links the alleged precursors to earthquakes, statistical evidence for
a correlation is lacking, and natural or artificial causes unrelated
to earthquakes have not been compellingly excluded (11).
In other fields threshold signals have often been erroneously claimed as important
physical effects (12);
most if not all "precursors" are probably misinterpreted as well.
Unfortunately, each new claim brings a new set of proposed
conditions, so that hypothesis testing, which is what separates
speculation from science, is nearly impossible.
Chinese seismologists claimed that the 4 February 1975 Haicheng
(magnitude = 7.3) earthquake was successfully predicted and that "very few people
were killed" (13).
However, an official publication in 1988 (14)
states there were 1328 deaths and 16,980 injured. This disparity
casts doubt on claims [HN19]
for the Haicheng prediction. China's Cultural Revolution was still
taking place in 1975. An American delegation's report (15)
captures the remarkable atmosphere: "Earthquake prediction was not a
minor experiment.... Indeed, belief in earthquake prediction was
made an element of ideological orthodoxy that distinguished the true
party liners from right wing deviationists." The possibility that
political pressures caused inaccuracies in claims for the Haicheng
prediction cannot be excluded. An intense swarm of
microearthquakes, many of which were large
enough to be felt by local residents,
began over 24 hours before the main shock (15).
These microearthquakes might well have induced
some spontaneous evacuation. At least 240,000 people died in the
1976 Tangshan, China, earthquake, which was not predicted.
and co-workers claim to be able to predict earthquakes in Greece on the basis of
geoelectrical observations (16),
but our analyses show their claims to be without merit (17,18).
Some of the geoelectrical signals are artifacts of industrial origin
and there is no compelling evidence linking any of the geoelectrical
signals to earthquakes. Controversy lingers
primarily because Varotsos's claims have not
been stated as unambiguous and
objectively testable hypotheses (20).
Is prediction inherently impossible or just fiendishly difficult?
In practice, it doesn't matter. Scientifically, the question can
be addressed using a Bayesian approach
Each failed attempt at prediction lowers the a priori probability
for the next attempt. The current probability of successful
prediction is extremely low, as the obvious ideas have been tried and rejected for over 100
Systematically observing subtle phenomena, formulating hypotheses,
and testing them thoroughly against future earthquakes would require immense
effort over many decades, with no guarantee of success. It thus
seems unwise to invest heavily in monitoring possible precursors.
Seismology can, however, contribute to earthquake hazard
Statistical estimates of the seismicity expected in a general region
on a time scale of 30 to 100 years (22)
[as opposed to "long-term predictions" of specific earthquakes on particular faults
within a few years (23)]
and statistical estimates of the expected strong ground motion are
important data for designing earthquake-resistant structures. Rapid
determination of source parameters (such as location and magnitude)
can facilitate relief efforts after large earthquakes. Warnings of tsunamis [HN26]
(seismic sea waves) produced by earthquakes also contribute
significantly to public safety. These are areas where earthquake
research can greatly benefit the public.
References and Notes
Supplementary Discussion from References
1, 10 and 23:
- See R. J. Geller, Astron. Geophys.
38, 16 (February/March 1997) for a compilation of
pro-prediction items in the mass media. For past Perspectives, see
C.-Y. King, N. Koizumi, Y. Kitagawa, Science
269, 38 (1995); J. Vidale, ibid.
271, 953 (1996); and P. G. Silver and H. Wakita,
ibid. 273, 77 (1996). Supplementary
discussion and supporting citations are available at [SUPPL.
- There was intense optimism about
prediction in the early to mid-1970s [C. H. Scholz, L. R. Sykes,
Y. P. Aggarwal, Science 181, 803 (1973);
F. Press, Sci. Am. 232, 14 (May 1975);
"Forecast: Earthquake," Time 106, 38 (1
September 1975)], but this optimism was
soon recognized to be unwarranted [R. A. Kerr,
Science 200, 419 (1978); C. R. Allen,
Bull. Seismol. Soc. Am. 72, S331
(1982)]. The fundamental flaw was that the prediction scenarios
were not stated as testable hypotheses.
- H. O. Wood and B.
82, 219 (1935); J. B. Macelwane, Bull.
Seismol. Soc. Am. 36, 1 (1946); C. F.
Richter, Elementary Seismology (Freeman, San Francisco,
1958), pp. 385-387.
- C. F. Richter, Bull.
Seismol. Soc. Am. 67, 1244 (1977).
- Assessment of Schemes for
Earthquake Prediction, meeting held 7-8 November 1996, London. See meeting
reports by I. Main [Nature 385, 19
(1997)] and R. J. Geller [Eos
78, 63 (1997)].
- P. Bak, How Nature Works:
The Science of Self-Organized Criticality (Copernicus, New
York, 1996). Publisher's
Synopsis of the book and order form:
- M. Otsuka, Phys. Earth
Planet. Inter. 6, 311 (1972); J. Brune,
J. Geophys. Res. 84, 2195 (1979); P. Bak
and C. Tang, ibid. 94, 15635 (1989); J.
Mori and H. Kanamori, Geophys. Res. Lett.
23, 2437 (1996).
- Y. Y. Kagan, Physica D
77, 160 (1994).
- I. Main, Rev. Geophys.
34, 433 (1996).
- See M. Wyss, Ed.,
Evaluation of Proposed Earthquake Precursors (American
Geophysical Union, Washington, DC, 1991). Supplementary discussion
and supporting citations are available at [SUPPL.
- D. L. Turcotte, Annu. Rev.
Earth Planet. Sci. 19, 263 (1991).
- I. Langmuir, Phys.
Today 42, 36 (October 1989); P. W. Anderson,
ibid. 43, 9 (December 1990); G. Taubes, Science
275, 148 (1997).
- At the time, A. L. Hammond
[Science 192, 538 (1976)] stated
"...very few people were killed, although more than 1 million live
near the epicenter, because the earthquake was
predicted and the population
evacuated--the first known instance of a major quake successfully
predicted and disaster prevented or
mitigated on such a scale," and D. Davies [Nature
258, 286 (1975)] stated "There was enormous
damage--a town of 100,000 is being completely rebuilt--but few
- Y.-D. Quan, The Haicheng,
Liaoning Province, Earthquake of M7.3 of 4 February 1975, in
Earthquake Cases in China, Z.-C. Zhang, Ed. (State
Seismological Bureau Publication in Chinese, Seismological Press,
Beijing, 1988), pp. 189-210. In some
cases, disasters in China during the Cultural Revolution were
concealed. As many as 230,000 people died in the collapse of two
dams in southern China in August 1975, but this tragedy was only
revealed 20 years later ["China: History warns," The
Economist, 30 (25 February 1995)].
- C. B. Raleigh et al.,
Eos 58, 236 (1977); see also R. D.
Adams, Earthquake Eng. Struct. Dyn. 4,
- P. Varotsos et al., in
A Critical Review of VAN, J. Lighthill, Ed. (World
Scientific, Singapore, 1996), pp. 29-76 Here
you can read a one-page synopsis of Lighthill's book, including
- R. J. Geller, ibid., pp. 155-238.
- F. Mulargia and P. Gasperini,
Geophys. J. Int. 111, 32 (1992); Y. Y.
Kagan and D. D. Jackson, Geophys. Res.
Lett. 23, 1433 (1996).
- S. Gruszow et al.,
ibid., p. 2025. This page
provides the Table of Contents for the Special Issue of
Geophysical Research Letters, Volume 23, Number 11, 1996.
- "Debate on Evaluation of the
VAN Method," ibid., p. 1291. This page
provides the Table of Contents for the Special Issue of
Geophysical Research Letters, Volume 23, Number 11, 1996.
- P. W. Anderson, Phys.
Today 45, 9 (January 1992).
- Y. Y. Kagan and D. D.
Jackson, J. Geophys. Res.
99, 13685 (1994) Abstract;
D. D. Jackson et al., Bull.
Seismol. Soc. Am. 85, 379 (1995); I. Main,
ibid., p. 1299.
- Y. Y. Kagan and D. D.
Jackson [J. Geophys. Res.
100, 3943 (1995)] Abstract;
F. Mulargia and P. Gasperini [Geophys. J. Int.
120, 453 (1995)] and Y. Y. Kagan [Bull.
Seismol. Soc. Am. 86, 274 (1996)] question
the models invoked to justify long-term predictions. Supplementary
discussion and supporting citations are available at [SUPPL.
- A. M. Dziewonski, G. Ekström,
M. P. Salganik, Phys. Earth Planet Inter.
97, 3 (1996).
- R. E. Abercrombie, Tectonophysics
261, 1 (1996); and J. N. Brune,
Geophys. Res. Lett. 21, 1647 (1994) Abstract.
- We thank S. Stein for valuable
Discussion from note
Belief in earthquake prediction is
widespread, as indicated by the following. (i) An opinion poll by
Japan's Office of the Prime Minister in September 1995, which revealed that 34.6%
of the public thought the "Tokai earthquake" (a magnitude M = 8
earthquake near Shizuoka, about 150 km west of Tokyo, which since
1976 has been claimed by some researchers and
government agencies to be imminent) could be predicted (about half of these
respondents thought all earthquakes with M 7 could be predicted); 44.5 % thought
prediction was impossible; 20.9% didn't know or gave other
answers. (ii) A newspaper article with the title "Scientists
Upbeat on Earthquake Prediction" (Los
Angeles Times, 22 December 1996, p. A3). (iii) See R. A.
Kerr, Science, 253, 622 (1991); W.
Spence et al., U. S. Geol. Surv. Circ. 1083 (1993) click here
for additional information about the Spence Report; and R. J.
Geller, Astron. Geophys. 38, 16
(Feb/Mar 1997) for information on many other pro-prediction items
in the mass media. (iv) After the 17 January 1994 Northridge,
California, event, rumors of the prediction of an even larger
earthquake were so prevalent that the California Institute of
Technology (Caltech) had to issue the following statement:
"Earthquake Prediction Rumors Are False. In response to rumors
about imminent major quakes, Caltech seismologists are saying that
earthquakes cannot be predicted. Aftershocks will
continue. However, the rumor of the prediction of a major
earthquake is false. Caltech cannot release predictions since it
is impossible to predict earthquakes." And finally, (v) there
have been several news articles in
Science that discuss earthquake prediction. We think
these stories accord too much emphasis to the views of
pro-prediction researchers; however, as negative views are also
reported, the stories could arguably be characterized as accurate.
Unfortunately, the headlines and sub-headlines are sometimes much
more pro-prediction than warranted by the contents of the stories.
For example, a Research News story on the Greek "VAN" group [R.A.
Kerr, Science, 270, 911 (1995)] was headlined
"Quake Prediction Tool Gains Ground," and the sub-headline of a
story on earthquake prediction in China [H. Li and J.D. Mervis,
Science, 273, 1484 (1995)] was "A vast, 30-year
effort to monitor the earthquakes that regularly shake
China has led to unprecedented---and controversial---success in
predicting them." In our view the former story does not show any
"ground being gained," and the latter story
presents no evidence of "unprecedented success." Readers are
encouraged to judge for themselves.
- Discussion from note
A group of prediction researchers established
validation criteria (including a precise definition of the
anomaly, an explicit statement of the signal-to-noise ratio,
detection at more than one station, and full disclosure of both
negative and positive results) and invited nominations of
precursor candidates. Only 31 nominations were submitted; none of
these fully satisfied the validation criteria. As these
nominations were presumably the cream of the crop, the fact that
not one fully met the validation criteria is strong empirical
evidence against the existence of the type of precursors required
for prediction. (Three of the 31 precursor nominations were placed
on a "preliminary list of significant earthquake precursors,"
despite failure to fully meet the validation criteria: One lacked
a clear definition of what constitutes an "anomaly" and a
comprehensive statistical evaluation; a second was not supported
by a quantitative analysis, and the number of false alarms and missed
events was not evaluated; and a third was seen for one event at
only one station, and there was no quantitative definition of what
constituted an anomaly.) Further evaluations of precursor case
studies by the above group of prediction researchers are presented
by M. Wyss, Ed., Pure Appl. Geophys. 149, 3 (1997).
- Discussion from note
Long term predictions were issued in 1976 for the
Tokai region in Japan [the initial publications were all in
Japanese; see K. Ishibashi in, Earthquake Prediction: An
International Review, D. W. Simpson and P. G. Richards, Eds.
(Ewing Monograph Series, Am. Geophys. Union, Washington, DC,
1981), pp. 297-332, for a discussion in English and references]
and in 1985 for the Parkfield region in California [W. H. Bakun
and A. G. Lindh, Science 229, 619 (1985)]; both
predictions have failed, as no large earthquakes have occurred. In
contrast, severely damaging earthquakes in California [Loma
Prieta in 1989 (see below), Landers in 1992, Northridge
in 1994] and Japan (Okushiri Island in 1993, and Kobe in 1995) occurred on faults for
which long-term predictions had not been issued. J.C. Savage [Bull.
Seismol. Soc. Am. 83, 1 (1993)] discusses and
criticizes the "Parkfield prediction fallacy." Y. Y. Kagan
[Tectonophys. 270, 207 (1997)] questions the claim
that quasi-periodic "characteristic earthquakes" regularly occur at
Parkfield. After the 1989 Loma Prieta earthquake there was a claim
that a relatively general long term seismicity forecast--as
opposed to a long term prediction for the particular fault that
ruptured--had been successful [U.S. Geological
Survey Staff, Science 247, 286 (1990)]. But this claim
proved controversial [R. A. Kerr, ibid. 249, 860 (1990)], and a
statistical analysis strongly argues against this claim [J. C.
Savage, Geophys. Res. Lett. 19, 709 (1992)].
Related Resources on the World Wide
- The SeismoSurfing
Index provides comprehensive links to seismological resources
on the Internet.
- The National Earthquake
Information Center of the U. S.
Geological Survey provides a
near real-time bulletin of global earthquake activity and global
earthquake maps. USGS also has an "Earthquake Information from
USGS" page primarily dealing with Northern California, but
also data on the Parkfield
study and a general discussion on the use
of foreshocks to estimate the odds of larger events in the
- The Incorporated
Research Institutions for Seismology is a university research
consortium dedicated to exploring Earth's interior through the
collection and distribution of seismographic data.
- The British Geological Survey's Web page has an Earthquake
FAQ that answers many common questions.
- The Seismological Society
of America, the Earthquake
Engineering Research Institute, and the International
Association of Seismology and Physics of the Earth's Interior
all maintain home pages on the Web.
- The Earthquake
Research Institute, University of Tokyo, has information about
seismic activity and their Earthquake
Prediction Research Center .
- Glossaries of seismological terms are available at the California
Institute of Technology, and the
National Earthquake Information Center. Excerpts from the
Parent's Guide to Earthquakes by Lucy Jones of the
USGS are also available.
Robert Geller's Home Page
describes his research interests.
Jackson's Home Page summarizes
his research interests and lists his publications.
- Yan Kagan's Home
Page summarizes his research interests and lists his
- F. Mulargia can
be reached via the Department
of Physics' Home Page at the Universita di Bologna, Italy.
- The Royal Astronomical Society
and its affiliated Joint
Association for Geophysics held a discussion meeting in
November 1996 on Assessment
of schemes for earthquake prediction .
- The US National Academy of Sciences
held a symposium (attendance and presentation by invitation
only) on earthquake prediction in February 1995, for which
abstracts are available. The introduction Earthquake
prediction: The scientific challenge was given by L. Knopoff.
- K. Aki gave a review of
prediction in Reviews of Geophysics, vol. 33, 1995,
as part of the U.S. National Report to International Union of
Geodesy and Geophysics 1991-1994.
- The USGS Cascades Volcano
Observatory offers definitions
and descriptions of Magnitude, Intensity, and the Modified
- Michigan Technological University,
Department of Geological Engineering and Sciences, presents an
Magnitude Scale and Classes Chart as part of UPSeis, a new
program created to teach young people about Earth.
- The fundamentals of
faulting are reviewed in Earthquake ABCs
at the Southern California
Earthquake Data Center .
- The Landers
Earthquake page has links to MPEG movies of the
rupture and animations of the
aftershocks. Related pages about the Northridge
earthquake and the faults of
Southern California are also available.
- M. Willemse (Stanford University,
Department of Geological and Environmental Sciences) provides
links to images
of fracture patterns, strike-slip faults, and normal faults.
- K. M. Cruikshank (Geology Department, Portland
State University) has a comprehensive
bibliography on faulting.
- A description of the Richter
scale is provided by NORSAR, a geophysics
research institution supported by the Research Council of
- The online pages of the
science radio series Earth and
Sky has information on Charles
Richter and the magnitude scale he developed.
- The Santa Fe Institute presents
a discussion of Self-Organized
Criticality that includes applications to sandpiles and
document delivery over the Web.
- R. Devaney of the Boston
University Math Department has a Web page about chaos and
fractals, including a discussion of self-similarity
and scale invariance.
- At the
November meeting of the Royal Society, I. Main
discussed the difficulties
of defining precursory phenomena.
- The official position
of the government of the People's Republic of China on recent
prediction research is outlined in the China Science and
Techology Newsletter (The State Science and Technology
Commission). See also the review by Aki on
prediction claims (earlier hypernote).
- A special issue of
Geophysical Research Letters (27 May 1996) edited by R.
J. Geller contains reports by Varotsos
and his collaborators, along with reports critical of his methods.
brief definition and a simple example of using Bayes' Theorem
is presented in the Statistics
for Engineers course at the Faculty of Engineering,
University of Wollogong, Australia.
- A lecture
on the hazards of earthquakes is offered by the Department of Earth Sciences &
The Institute of Tectonics, University of California, Santa
- A guide to
international building codes that are designed to mitigate
earthquake damage is provided by the National Center for
Earthquake Engineering Research of SUNY Buffalo.
- The Western States
Seismic Policy Council has images of the aftermath of the 1995
Kobe earthquake among others.
- The US Geological
Survey's Homepage for Earthquakes points to a variety
of hazard topics, such as the National Seismic Hazard
- The Japanese word tsunami
is written as two characters meaning "harbor wave." The Tsunami Web
site is an online information resource about these great
- The Harvard Centroid-Moment
Tensor (CMT) database is a catalog of large earthquakes maintained by the Harvard Seismology
group. A query
page for the CMT database is available at the Earthquake
Research Institute, University of Tokyo.
Also see the archival
list of Enhanced Perspectives
This article has been cited by other
- Sornette, D. (2002). Predictability of catastrophic events:
Material rupture, earthquakes, turbulence, financial
crashes, and human birth. Proc. Natl. Acad. Sci. U. S. A.
99: 2522-2529 [Abstract]
- Sammis, C. G., Sornette, D. (2002). Positive feedback, memory,
and the predictability of earthquakes. Proc. Natl. Acad.
Sci. U. S. A. 99: 2501-2508 [Abstract]
- Knopoff, L. (2000). The magnitude distribution of declustered
earthquakes in Southern California.
Proc. Natl. Acad. Sci. U. S. A. 97: 11880-11884 [Abstract]
- Wyss;, M., Aceves, R. L., Park;, S. K., Geller, R. J., Jackson, D. D., Kagan, Y. Y.,
Mulargia;, F. (1997). Cannot Earthquakes Be Predicted?. Science 278:
Volume 275, Number 5306, Issue of 14 Mar 1997, pp.
Copyright © 1997 by The American Association for the
Advancement of Science. All rights reserved.