Walter Nyamukondiwa, Kariba Bureau
A moderate 3,9 magnitude earthquake hit Kariba and surrounding areas Monday morning with no reports of damage recorded so far.
The quake has been attributed to the upward or downward variation in water levels in Lake Kariba with the Zambezi River Authority recording a steady rise in water levels over the last two months.
As of June 18, 2020 water levels had risen to 481,22m (40,97 percent of usable storage for power generation) compared to 479,63 (29,12 percent) on the same day in 2019.
The Meteorological Services Department’s Seismology Section triangulated the epicentre of the earthquake which occurred at around 7.11am on longitude 28.581E and latitude -16.678S.
“An earthquake of magnitude 3.9 was felt in Kariba Urban and surrounding areas today on 22 June 2020 at 07:11 local time.
“The determined earthquake parameters show that the earthquake occurred at Latitude -16.678S and Longitude 28.581E.The epicentre is in Kariba Dam and it was widely felt in Kariba urban,” said a report from Met Department.
Several people confirmed feeling the ground shaking and rattling of utensils in the house.
MSD said further investigation to determine the intensity of the earthquake and areas it affected were underway.
The epicentre of the earthquake has been determined to be in Kariba Dam.
“No reports of damage were received however more inquiries would be made to determine its intensity in the locality and to determine the exact areas it was felt,” reads a statement from MSD.
“Most of the earthquakes in this region are attributed to the reservoir/dam and they are called reservoir induced earthquakes. The seismic activity arises as a result of the impoundment (confinement of water in a reservoir) of the dam.”
Since the filling of the lake in 1963, seismic activity has been recorded.
This is also compounded by the lake falling in the Mid-Zambezi basin.
According to a ZRA report, lake levels are rising steadily as inflows continue.
“The Lake level has continued rising steadily, closing the period under review at 481.22m (40.97% usable storage) on 18th June 2020. Last year on the same date, the Lake level was at 479.63m (29.12% usable storage),” reads the report.