via Quake rattles Kariba | The Herald January 12, 2016
Walter Nyamukondiwa Chinhoyi Bureau
A 4,6 magnitude earthquake hit the Kariba area and parts of neighbouring Zambia on Saturday morning, raising fears about the safety of the vulnerable Kariba dam wall, although no damages were recorded on it and other infrastructure.
Kariba residents and their northern neighbours woke up to the rattling effects of the quake which lasted for about 15 seconds on Saturday at around 4am.
The quake was recorded by various organisations, with the Zambezi River Authority confirming the incident.
ZRA chief executive officer, Mr Munyaradzi Munodawafa, said yesterday that their infrastructure at Kariba was safe.
“Yes, there was a mild earthquake on Saturday, but the dam wall was not affected,” said Mr Munodawafa. “No houses were damaged or infrastructure and that means the acceleration and velocity of the quake was not high.”
Mr Munodawafa said the seismic risk analysis and diagnosis machine that monitors and assesses risk on the Kariba dam wall did not record any damage.
The Kariba dam wall was reported to have developed cracks way back, raising fears of a major catastrophe in the event of further strain.
The cracks are being attended to, with work and consultations at various stages.
Mr Munodawafa said a full assessment of Saturday’s quake was still underway, with a full report expected soon.
Kariba resident Mr Sam Mawawo confirmed being woken up by the quake on Saturday morning.
“I was awakened by the rattling pots, pans and plates in the house which lasted for some seconds, but it was frightening,” he said.
There are unconfirmed reports of one house having developed a crack as a result of the impact in the Baobab area of Kariba, but there were indications the house was not structurally sound.
Kariba district administrator Mr Amigo Mhlanga said he was yet to be briefed on the effects of the earthquake.
“My assistants are still assessing the situation and they will brief me of what took place and if there is any effect at all,” he said.
Traditionalists view the tremors as a confirmation from the gods of their happiness following the conducting of rituals there recently.
Further north, the tremor was felt in most parts of the capital Lusaka and southern provinces of Zambia.
The United States Geographical Survey estimated the quake at 4,6 in magnitude.
The Earthquaker-Report.com, which monitors earthquakes, recorded what it termed “a moderate earthquake” in Kariba.
Most people on both sides of the Zambezi River feared for the worst in view of reports of the vulnerability of the Kariba dam wall.
The US Geographical Survey notes that earthquakes with magnitude of up to 2,0 on the Richter Scale (a unit of measurement of earthquakes) are normally known as micro-earthquakes and are generally undetected, only picked up by localised seismographs.
Those of magnitudes of 4.5 or greater are strong enough to be recorded by sensitive seismographs.
Online earthquake monitors triangulated the epicentre about 31 kilometres from Chirundu at a depth of 10km underground.