Reports are cropping up online that appear to show deep chasms, exacerbated by rainfall, in Kenya’s Narok County. One tear in the earth is reportedly 15 meters (50 feet) deep and 20 meters (66 feet) wide.
Speaking to the Daily Nation, a geologist has suggested that this odd phenomenon is the manifestation of “zones of weakness” within the region. Some of these cracks are new, but some are old ones previously buried in fresh volcanic ash, and heavy rains have suddenly washed the ash out and exposed them.
This has certainly brought some geological drama to the area, which has seen families evacuated tout suite. One family were having dinner at home when they were forced to flee after a new fissure opened up beneath their feet and reportedly cut their home in two.
So what exactly is going on here?
This part of Kenya is clearly showing some rather extreme-looking behavior at the surface, but don't panic: This is possibly due to a highly localized expression of the valley's regular rifting activity. In fact, it's probably just a gully that's being eroded or exposed by surface processes, although there's simply not enough information to say for sure at this point.
There seems to be some confusion regarding what's actually going on in this part of the world on a larger scale, however, so let's clear a few things up.
East Africa is breaking up. A huge tectonic plate boundary 5,000 kilometers (about 3,100 miles) long is running up along the eastern section of the continent, which is manifested at the surface as the East African Rift System (EARS), which has many beautiful nuances and complexities.
The African plate has split into the Somalian and Nubian tectonic plates, which are pulling away from each other, a process that began around 25 million years ago. The Arabian plate is also moving away, and the result is that the triple-junction rift network in the Afar region is shaped like a Y.
This active rift zone has an incredibly slow rate of spreading of a few millimeters per year on average. Ultimately, this means that around 10 million years from now, a new ocean will emerge as the EARS continues to tear East Africa apart.
Clearly, slow and steady wins the race here. The spreading rate varies across the rift, however, with some parts moving slower or faster than others.