For his part, however, Simpson (along with the British seismologists D. I. Gough and W. I. Gough) argues that pore-pressure changes played only a small part in reservoir-induced earthquakes caused by high-pressure fluid injection. Thus he writes: “It should be noted . . . that the increases in pore pressure involved in the case of fluid injection are very much higher than those created by a deep reservoir.” [37] He also notes that those earthquakes caused by fluid injection all took place at, or very near, a fault zone.
A further unanswered question is whether reservoir-induced earthquakes actually create stresses or simply serve to release existing ones. The British seismologist, Dr. R. D. Adams, regards it as
“generally accepted that induced seismicity only releases strains already stored in the region, perhaps bringing forward in time earthquakes which would have occurred in the future. In no cases should reservoirs increase the long-term seismic energy release, and it may be that an episode of induced seismicity will be followed by a compensating period of quiescence.” [38]
However, there is no reason to suppose that this is so. Simpson, for example, does not consider it at all clear “whether the reservoir changes only the timescale for the release of stress, triggering earthquakes which would eventually have occurred anyway, or whether it can modify the magnitude of possible earthquakes too.” [39]
Whatever the answer to that question, it now seems clear beyond any reasonable doubt that reservoirs can trigger off earthquakes – sometimes serious ones – even in areas where there has been no previous seismic activity. As Rothe puts it, when he builds dams,
“Man plays the role of the sorcerer’s apprentice: in trying to control the energy of the rivers, he brings about stresses whose energy can be suddenly and disastrously released.” [40]
That knowledge, however, does not seem to have had any influence on current dam building programmes. The Indian government, for instance, is at present constructing a large dam near Tehri on the Bhagirathi river in the mid-Himalayas, an area which has been marked by considerable seismic activity. Indeed, such activity appears to be on the increase: between 1971 and 1973 an average of one or two earthquakes occurred a year; in 1974, 5 earthquakes occurred; and in 1975, there were seven.
There also appears to be heavy cracking in the rocks of the river gorge where the Tehri dam is to be built. Those rocks, according to V. D. Saklani, President of the Tehri Bandh Virodhi Sangharsh Samati, are “most unlikely to be able to bear the weight of (the) 2.62 million acre feet of water to be impounded in the lake.” [41]
In the light of our present knowledge of reservoir-induced seismicity, it is difficult to see how the government of India can justify the construction of the Tehri dam. Nor is Tehri the only dam under construction which is likely to give rise to seismic activity. Worldwide, many other dams are being built – or planned – in areas known to be seismically active. It is surely only a matter of time before one of those dams causes a truly serious earthquake. If that earthquake also destroys the dam structure – thus releasing the massive volume of water impounded in the reservoir behind – it could kill tens, if not hundreds, of thousands of people in the surrounding area.
Table 5: Reservoir-induced changes in seismicity
| Dam name | Location | Height of dam (m) |
Volume of reservoir (Mm3) |
Year of impounding |
Year of largest earthquake |
Magnitude or intensity |
|---|---|---|---|---|---|---|
| Major induced earthquakes | ||||||
| Koyna | India | 103 | 2780 | 1964 | 1967 | 6.5 |
| Kremasta | Greece | 165 | 4750 | 1965 | 1966 | 6.3 |
| Hsinfengkiang | China | 105 | 10500 | 1959 | 1962 | 6.1 |
| Oroville * | USA (Calif.) | 236 | 4295 | 1968 | 1975 | 5.9 |
| Kariba | Rhodesia | 128 | 160368 | 1959 | 1963 | 5.8 |
| Hoover | USA (Ariz.) | 221 | 36703 | 1936 | 1939 | 5.0 |
| Marathon | Greece | 63 | 41 | 1930 | 1938 | 5.0 |
| Minor induced earthquakes | ||||||
| Benmore | New Zealand | 118 | 2100 | 1965 | 1966 | 5.0 |
| Monteynard | France | 155 | 240 | 1962 | 1963 | 4.9 |
| Kurobe | Japan | 186 | 199 | 1960 | 1961 | 4.9 |
| Bajina-Basta | Yugoslavia | 89 | 340 | 1966 | 1967 | 4.5 – 5.0 |
| Nurek | USSR | 317 | 10400 | 1969 | 1972 | 4.5 |
| Clark Hill | USA (S.C.) | 67 | 2500 | 1952 | 1974 | 4.3 |
| Talbingo | Australia | 162 | 921 | 1971 | 1972 | 3.5 |
| Keban | Turkey | 207 | 31000 | 1973 | 1974 | 3.5 |
| Jocassee | USA (S.C.) | 133 | 1430 | 1972 | 1975 | 3.2 |
| Vajont | Italy | 261 | 61 | 1961 | 1963 | |
| Grandval | France | 88 | 292 | 1959 | 1963 | V |
| Canalles | Spain | 150 | 678 | 1960 | 1962 | V |
| Changes in micro-earthquake activity | ||||||
| Kamafusa | Japan | 46 | 45 | 1970 | 2.5 | |
| Pieve de Cadore | Italy | 112 | 68 | 1949 | 2.0 | |
| Grancarevo | Yugoslavia | 123 | 1280 | 1967 | 1.0-2.0 | |
| Hendrik-Verwoerd | S. Africa | 88 | 5954 | 1970 | 2.0 | |
| Schlegeis | Austria | 130 | 129 | 1971 | 0.0 | |
| Transient changes in seismicity | ||||||
| Oued Fodda | Algeria | 101 | 228 | 1932 | ||
| Camarilles | Spain | 44 | 40 | 1960 | 1961 | 3.5 |
| Piasta | Italy | 93 | 13 | 1965 | 1966 | VI-VII |
| Vouglans | France | 130 | 605 | 1968 | 1971 | 4.5 |
| Contra | Switzerland | 220 | 86 | 1965 | 1965 | |
| Decreased activity | ||||||
| Tarbela | Pakistan | 143 | 13687 | 1974 | ||
| Flaming Gorge | USA (Utah) | 153 | 4647 | 1964 | ||
| Glen Canyon | USA (Ariz.) | 216 | 33305 | 1964 | ||
| Anderson | USA (Calif.) | 72 | 110 | 1950 | ||
Other possible cases
Height in meters follows dam name (n.a. = not available),
USA – Shasta (183), Calif.; San Luis (116), Calif.; Palisades (82), Utah; Clark Canyon (40), Mont.; Kerr (n.a.), Mont.; Cabin Creek (n.a.), Colo.; Rocky Reach (n.a.), Wash.
Australia – Eucumbene (116); Warragamba (137).
Pakistan – Mangla (116).
Spain – EIGrado (130).
India – Kinnersani, Parambikulam, Sharavathi, Ukai, Ghirni, Mula (all n.a.).
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References
1. David Henry, ‘Designing for Development: What is appropriate technology for Rural Water and Sanitation’, in Carl Widstrand, The Social and Ecological Effects of Water Development in Developing Countries, Pergamon, Oxford, 1978, p.365.
2. Philip Williams, ‘Dam Design; is the technology faulty?’ New Scientist, 2 February 1978.
3. Ferdinand Budweg, USCOLD newsletter, November 1982. Quoted by Philip Williams, ‘Damming the World’, Not Man Apart, October 1983, p.11.
4. J. P. Rothe, personal communication to Edward Goldsmith, 1983.
5. ‘Landslide Threat to Lima’s Power Dam’, WorldWater, Vol. 5, No. 6, June 1982, pp.7-8.
6. ‘India’s worst dam disaster’, Water Power and Dam Construction, November 1979. Quoted by Philip Williams, op.cit. 1983, p.11.
7. Carl Widstrand, ‘Conflicts over Water’, in Carl Widstrand (Ed), Water Conflicts and Research Priorities, Pergamon, Oxford, 1980, p.147.
8. E. G. Giglioli, ‘The National Organization of Irrigation (Kenya)’, in R. Chambers and J. Morris (Eds), Mwea, an Irrigated Rice Settlement Scheme in Kenya, Weltforum Verlag, Munich, 1973. Quoted by Carl Widstrand, op.cit. 1980, p.131.
9. Carl Widstrand, op.cit. 1980, p.132.
10. Ibid, pp.147-8.
11. ‘Salvador Rebels aim for hydro dams’, USA Today, April 12, 1983.
12. Philip Williams, op.cit. 1983, p.11.
13. Carl Widstrand, op.cit. 1980, p.138.
14. Philip Williams, op.cit. 1983, p.11.
15. Philip Williams, Damming the World, Philip Williams and Associates, Pier 33 North, The Embarcadero, San Francisco, 1983, p.13.
16. David W. Simpson, ‘Seismicity Changes associated with reservoir loading’, Engineering Geology 10 (1976) 123-150, p.123.
17. Ibid, p.123.
18. Ibid, p.124.
19. J. P. Rothe, ‘Man-Made Earthquakes’, Tectonophysics, 1970, pp.215-238.
20. J. P. Rothe, ‘Fill a Lake, start an Earthquake’, New Scientist, Vol. 39 No. 605, 11 July 1978, p.78.
21. J. P. Rothe, ‘Summary: Geophysics Report’ in William C. Ackermann et. al. (Eds), Man-Made Lakes, Their Problems and Environmental Effects, American Geophysical Union, Washington DC, 1973, pp.441-442.
22. P. M. Mane, ‘Earth Tremors in Koyna Project area’, Ninth Congress on Large Dams, Istanbul, op.cit. 1973, pp.445-447. Quoted by J. P. Rothe, op.cit. 1973, pp.446-447.
23. J. P. Rothe, op.cit. 1973, p.446.
24. UNESCO Working Group on Seismic Phenomena associated with Large Reservoirs, Report of First Meeting, UNESCO, 14-16 December 1970, SC/CONF. 200 4, paris, 6 March 1971, p.3.
25. UNESCO Working group on Seismic Phenomena associated with Large Reservoirs, Report of Second Meeting, UNESCO, 14-17 December 1971, SC-71/CONF. 42/3, p.4.
26. J. P. Rothe, Note sur les seismes de Vouglons, unpublished paper, June-July 1971.
27. J. P. Rothe, op.cit. 1973, p.445.
28. T. R. Toppozoda and P. W. Morrison, ‘Earthquakes and Lake Levels at Oroville Butte Cao. California’, Earthquake Notes, January-March 1981. Vol. 52 No. 1, p.27.
29. Ibid, p.28.
30. T. R. Topozoda, J. H. Bennett and C. H. Kramer, ‘Earthquakes and Water Levels at Mono Lake, Mono County, California, Earthquake Notes, Jan-March 1981, Vol. 52, No. 1, p.28.
31. Jean Coulomb, ‘Sismologies – Un nouvel exemple de sismicite provoqueremarques sue une note de Jean Delannay, Rene Guirand et Christian Weber’, Note du 2 November 1981 de J. P. Rothe, CR Acad. Sc. \lang2057 paris. t293 C 7, December 1981, Serie II, p.953.
32. R. M. Kebeasy, M. Maamour and E. M. Ibrahim, ‘Aswan Lake induced earthquakes’, Bulletin of the International Institute of Seismology and Earthquake Engineering, Vol. 19, 1981, pp.155-160.
33. J. P. Rothe, op.cit. 1973, p.450.
34. David W. Simpson, op.cit. 1976, p.147.
35. Ibid, p.130.
36. J. P. Rothe, op.cit. 1973, p.452.
37. David W. Simpson, op.cit. 1976, p.141.
38. R. D. Adams, ‘Incident at the Aswan Dam’, Nature, Vol. 301, 6 January 1983, p.14.
39. David W. Simpson, op.cit. 1976, p.146.
40. J. P. Rothe, op.cit. 1978, p.78.
41. V. D. Saklani, ‘Tehri Dam Project that spells disaster’, Tehri Bandh Virodhi Sangharsh Samiti, Tehri Garhwal (undated), p.viii.
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