Costs and benefits of earthquake prediction studies in Greece

Abstract

S U M M A R YFor the following reasons, a (hypothetical) successful earthquake prediction in Greece would be of, at best, limited benefit to society. (1) On average, less than 5 per cent of sizeable earthquakes (that is magnitude greater than 4.5) cause significant damage or loss of life. (2) Organized evacuation of urban centres is unlikely to be successfully accomplished, because the public lacks confidence in the authorities and cannot be expected to respond promptly; panic and other undesirable side-effects can also be anticipated. ( 3 ) The lead time between a short-term prediction and earthquake occurrence is too short for most actions aimed at reducing or eliminating primary or secondary earthquake effects; in any case, most such actions would be superfluous if appropriate longer-term preparedness plans were implemented. (4) Prediction of 'an earthquake' is not an appropriate objective in an area such as Greece, which experiences complicated and long seismic sequences consisting of several destructive events, and large earthquakes with anomalous meizoseismal areas. (5) The seismic death toll in Greece is relatively small (less than 10 people per year over the last 40 years), and due to recent changes in building styles and construction practices, current morbidity is mainly associated with the failure of multistorey buildings. This death toll could be more effectively eliminated by identifying weaknesses and structural intervention than by earthquake prediction. Hence, earthquake prediction in Greece, even if it were scientifically feasible, would not be cost-effective; alternative use of funding could be expected to save more lives with much greater certainty. Over the past 15 years, the VAN group's research on earthquake prediction has absorbed a substantial fraction of the resources devoted to earthquake research and protection in Greece. However, the VAN method has not advanced the nation's policy on earthquake protection planning, its results continue to be widely questioned by both the Greek and international scientific communities, and the underlying model is not commensurate with currently accepted thinking on earthquake generation and tectonophysics. Thus, VAN'S methods can be regarded as basic research rather than as an operational method for the reduction of seismic risk.

Assessment of schemes for earthquake prediction: Editor's introduction

“…Whereas the VAN group claim to have issued successful predictions for these events, Bernard et al conclude differently. Stiros (1997) gives an account of VAN from the perspective of seismologists and earthquake engineers in Greece. Mulargia (1997) analyses a case study of volcanic eruptions, whereas other authors (Geller 1997b;Kagan 1997) draw on a number of different cases.…”

“…Even to warrant the issuing of 'alerts' (as opposed to undertaking major evacuation measures), a level of accuracy is required which is much higher than the best meteorological forecasts can achieve. Bernard et al (1997) and Stiros (1997) discuss the effect of public earthquake predictions in Greece. Both conclude that any practical success which has been achieved has been due to local populations leaving their houses or taking other lossreduction actions in response to a significant increase in local seismic activity (i.e.…”