<P> The EAR is the largest seismically active rift system on Earth today . The majority of earthquakes occur near the Afar Depression, with the largest earthquakes typically occurring along or near major border faults . Seismic events in the past century are estimated to have reached a maximum moment magnitude of 7.0 . The seismicity trends parallel to the rift system, with a shallow focal depth of 12--15 km (7.5--9.3 mi) beneath the rift axis . Further away from the rift axis, focal depths can reach depths of over 30 km (19 mi). Focal mechanism solutions strike NE and frequently demonstrate normal dip - slip faults, although left - lateral motion is also observed . </P> <P> The Rift Valley in East Africa has been a rich source of hominid fossils that allow the study of human evolution . The rapidly eroding highlands quickly filled the valley with sediments, creating a favorable environment for the preservation of remains . The bones of several hominid ancestors of modern humans have been found here, including those of "Lucy", a partial australopithecine skeleton discovered by anthropologist Donald Johanson dating back over 3 million years . Richard and Mary Leakey have done significant work in this region also . More recently, two other hominid ancestors have been discovered here: a 10 - million - year - old ape called Chororapithecus abyssinicus, found in the Afar rift in eastern Ethiopia, and Nakalipithecus nakayamai, which is also 10 million years old . </P>

Mt kilimanjaro and mt kenya are that occur along the east african rift