Lightning carved the Drakensberg: Wits

15 October 2013 - 19:17 By Sapa
Tugela river. File photo.
Tugela river. File photo.
Image: Rudolph Botha/ Wikimedia Commons

Lightning strikes play a huge role in shaping mountain landscapes in Southern Africa, the University of the Witwatersrand said.

A study by researchers Jasper Knight and Stefan Grab, of the school of geography, archaeology and environmental studies, proved for the first time that lightning was responsible for some of the angular rock formations in the Drakensberg.

A compass was used to identify rocks containing a strong magnetic field.

"If you pass a compass over an area where a lightning strike occurred, the needle will suddenly swing through 360 degrees," Knight said in a statement.

He said many rocks that contained magnetic minerals were found in the Drakensberg.

"The energy of the lightning hitting the land's surface can partially melt the rock and when the rock cools down again, it takes on the magnetic imprint of today's magnetic field."

The researchers had mapped out the distribution of lightning strikes in the Drakensberg.

"We discovered that lightning significantly controls the evolution of the mountain landscapes because it helps to shape the summit areas, the highest areas, with this blasting effect."

Previously it was believed that the angular debris rocks were created by temperature changes.

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