By Lehlohonolo Lehana.
An earth tremor that measured 4.2 on the Richter scale has been tracked to Boksburg where the epicentre hit 10 kilometers underground.
Residents in parts of Gauteng said that they woke up to what felt like a tremor on Friday morning.
4.2 magnitude #earthquake. 15 km from #Boksburg, Gauteng, South Africa https://t.co/FgsuWdmz3o
— Earthquake Alerts (@QuakesToday) July 30, 2021
Many people in areas like Northcliff, Glenvista, Kensington, Germiston, Boksburg and even in the north of Pretoria said that they felt the ground shake for a few seconds just after 6.30am.
According to Volcano Discovery, there were two quakes of magnitude 8.2 and magnitude 6.1 respectively over the last 24 hours worldwide, as well as 12 quakes between 5.0 and 6.0 magnitude, and 65 quakes between 4.0 and 5.0 magnitude.
The biggest earthquake of the past 24 hours had an epicentre in the Gulf of Alaska – the strongest US quake in 50 years. It sparked tsunami fears for South Alaska and Hawaii.
According to the USGS, the earthquake hit 91km southeast of the town of Perryville, with a tsunami warning in effect for south Alaska and the Alaskan peninsula.
Videos shared on social media showed Kodiak residents evacuating to higher ground while tsunami warning sirens were heard blasting in the background. A buoy southwest in the region recorded “serious changes” in the water height.
Dr Alice-Agnes Gabriel, a seismologist at the Ludwig-Maximilians-Universität (LMU) in Germany, said the earthquake has an intermediate depth of 35km, which is deeper than USGS’s phase estimate of 23km.