Kariba hit by earthquake

Nqobile Bhebhe, Senior Reporter

An earthquake of magnitude 4.3 struck in Kariba and surrounding areas on Tuesday evening with officials saying tremors of such magnitude are not expected to affect the structural integrity of the Kariba Dam.

In a statement issued by the Zambezi River Authority’s chief executive officer, Engineer Munyaradzi Munodawafa on Thursday, the earthquake was felt at 22:03 hours.

The epicenter was triangulated by the Meteorological Services Department (MSD) of Zimbabwe to approximately 50km South of Kariba Dam near Bumi Hills, he said.

“An earthquake of magnitude 4.3 occurred and was felt in the Kariba and surrounding areas at 22:03 hours (10PM) on 2 August 2022,” said Eng Munodafawa.

He said although the area is a naturally active seismic zone, it started experiencing increased seismicity after the filling of Lake Kariba in the 1960s.

“Accordingly, the earthquakes are normal and expected. They are referred to as “reservoir induced tremors” because they are attributed to the presence of the lake.

“In the last twelve months, two earthquakes of equivalent magnitudes and several others of smaller magnitudes occurred south of the Kariba Dam. Of note are magnitude M4.5 and M4.6 earthquakes that occurred on 9 August 2021 and 24 May 2022, with epicentres near Binga and below the Lake respectively.

“We wish to assure the public and those domiciled in and around the affected areas that tremors of this magnitude are not expected to affect the structural integrity of the Kariba Dam.”

He added from inspections carried out on Wednesday morning that there were no unusual observations made nor from the analysis of dam safety data that is collected from several instruments that monitor the behaviour of the dam.