Earthquakes in Zimbabwe

Abstract

Earthquakes are one of the most destructive natural forces, in both human and economic terms. For example, since 1900, 10 earthquakes have occurred that each killed over 50 000 people. Earthquakes in modern industrialized areas can be also be very costly, even if well designed and constructed buildings save many lives. In Zimbabwe, beginning in February 1959 prompted by fresh seismic (earthquake) activity after the Kariba Dam was sealed in December 1958, seismograph stations began to be installed in the region. Seismographs detect ground vibrations. By 1970, the network consisted of 6 stations (including 1 each in Zambia and Malawi), was operated by the Zimbabwe Meteorological Services from the Goetz Observatory in Bulawayo. Almost all earthquakes in Zimbabwe occur in the Hwange-Zambezi-Kariba or Eastern Highlands areas. Sensitive engineering structures such as the Kariba Dam and power generating facilities around Hwange lie in these areas. However, the central part of Zimbabwe (including the two main cities, Harare and Bulawayo) has almost no earthquakes, only ~1% of the total. Fortunately, most earthquakes in Zimbabwe are quite small: of the ~3 400 earthquakes recorded in a 32 year period, only 30 exceeded a magnitude of 5 on the Richter Scale. The largest earthquake recorded here was in 1963, beneath the newly filled Lake Kariba, measuring 5.8 on the Richter Scale.



The Zimbabwe Science News Volume 34 Number 3&4, December 2000, pp. 51-53