Africans need to be more aware of earthquakes to cope with disasters — and there's no better place to start than in schools, says Chris Hartnady.
The probability and likely impact of major earthquakes in southern Africa are difficult to quantify.
The continent has limited historical records and there have been just three or four events of a magnitude of seven or higher on the Richter scale since 1900 — compared with hundreds globally in the last 30 years.
Yet a major earthquake disaster in the region is inevitable because wide areas of southern Africa are affected by the slow southward spread of the East African rift system. It is not a question of if, but when.
And the consequences would be so expensive in terms of mortality and economic cost that the risk of being ill-prepared is unacceptably high. Major earthquakes can lead to large-scale loss of life and property due to building collapse, fires and landslides on unstable slopes, and catastrophic disruption of dam walls, water mains, roads, railways and fuel pipelines.
Smaller quakes are damaging too
Careful monitoring and analysis of the many smaller earthquakes that occur annually can map the probable future locations of rare large events. But even smaller events can be a threat in Africa because of poor infrastructure and vulnerable populations.
A 2002 survey of significant earthquakes showed that the continent has suffered more than 50 events since 1980 that caused more than 23,000 deaths and injuries, and unquantified economic losses.
Africa's worst earthquake disaster was in Agadir, Morocco in February 1960, where more than 15,000 people were killed by an earthquake of only moderate magnitude (5.7).
A 1969 earthquake in Tulbagh, South Africa, of magnitude 6.3, resulted in only 12 deaths but damaged 70 per cent of the town's buildings and left most of the population temporarily homeless.
Natural geophysical hazards such as these cannot be prevented, but a passive attitude and only simple emergency response are likely to be inadequate.
African countries must prepare for earthquakes, both small and large, by assessing risk, reducing vulnerabilities over the long-term and enhancing coping capacities through advance planning.
Technology is to hand
In practice, this means identifying and analysing disaster risks, prioritising responses to them, and monitoring, reviewing and communicating seismic activity.
This, in turn, requires developing remote sensing and geo-informatics technologies to integrate weather, climate, hydro(geo)logical, space-geodetic and seismological observation systems.
There are new methods that can measure the slow motions of the African plates using ground-based global positioning system (GPS) instruments, in combination with radar satellites that detect subtle, centimetre-scale deformations along developing fault systems.
The good news is that African countries can sidestep much of the development cost and adopt the technologies that are already available. GPS instruments, for example, arerelatively inexpensiveandhave other remote sensing applications, such as meteorology (monitoring key atmospheric variables such as water vapour content) and space weather (monitoring the electron content of the ionosphere).
Showing that the earth moves
But improving the science of earthquake monitoring alone will not suffice. Reducing disaster risk depends on engaging people by building their awareness of natural geohazards and strengthening their ability to cope with earthquakes through rapid and effective emergency response.
The infrequency of major earthquake disasters in Africa means that local populations have neither historical experience nor traditional mythology of these events. We must counteract the lack of awareness of earthquakes and take steps to prepare for disasters in the long term.
One way to tell people that earthquakes can happen is to demonstrate the nanometre-scale vibrations of the numerous unfelt micro-earthquakes, so that they become known to almost everyone on a daily basis.
Achieving this requires extending earthquake monitoring to schools, where it can be shared by communities, and it can also be part of a wider educational effort to improve the mathematics and science skills of learners.
Educational seismology can build on curiosity about natural phenomena, and help teach a wealth of fundamental principles of physics and earth science.
The cost of educational seismographs has fallen dramatically in recent years, while networking software and high-quality classroom resources allow educators and learners to use state-of-the-art seismological data and tools in a wide variety of settings.
Sustainable development agencies must engage with education authorities to promote hazard awareness and community preparedness by influencing the development of new curricula, textbooks and teacher training in both primary and secondary schools.