LUSAKA/HARARE, Dec. 26 (Xinhua) -- The Zambezi River Authority (ZRA) said Thursday that a spate of earthquakes has struck the area around the Kariba Dam since Dec. 1 but assured the public that the dam, situated on the Zambezi River basin between Zambia and Zimbabwe, remains structurally sound.
ZRA, a binational organization managing the Zambezi River's waters for the benefit of both countries, said in a press release that seven earthquakes have recently hit the region, including a 4.9-magnitude tremor recorded Monday at a depth of 10 km. The epicenters of the quakes were located between 19 and 40 km from Kariba and surrounding areas.
The authority explained that the earthquakes are primarily reservoir-induced seismic activities caused by the presence of the reservoir and fluctuations in water levels due to drawdowns.
"The earthquakes are not only limited to Kariba as they have been reported from the filling and subsequent operation of several other large dams and reservoirs worldwide," the release said.
"The authority further wishes to inform its stakeholders and the public at large that in the interest of dam safety, it does not focus on magnitudes of the earthquakes, but the ground accelerations or vibrations that are generated from the event," ZRA Chief Executive Munyaradzi Munodawafa said.
ZRA also emphasized that the seismic activities in Kariba and surrounding areas since the dam's construction have been relatively minor, with no significant ground accelerations or vibrations recorded that would raise concerns about the safety of the dam wall.
The authority highlighted its rigorous monitoring protocols, including inspections and data analysis conducted after each seismic event as part of emergency preparedness measures. These assessments following the latest earthquakes revealed no unusual observations, with the dam continuing to exhibit behavior consistent with current loading conditions.
The Kariba Dam, the world's largest man-made reservoir by volume, remains a vital infrastructure for Zambia and Zimbabwe, ensuring water resource management and energy generation for the region. ■
