Seismologists Puzzle Over The Cause Of A Massive Crack In Kenya's Rift Valley

By on

CCSS NAS-4 Word Search
Photo Credit: Daily Nation (YouTube screen capture)

In mid-March, following an extended period of heavy rainfall, residents of the Mai Mahiu settlement in Kenya woke up to a big surprise – a massive crack in the Earth that appeared to have opened up almost overnight. Running several miles long and measuring 50 feet deep and 65 feet wide in some places, the terrifying fissure damaged several homes and caused a portion of the busy Mai Mahiu Narok-Nairobi highway to collapse.

The opening occurred along the East African Rift Valley, a 3,700-mile (6,000-kilometer) crack in the Earth that formed millions of years ago when the Nubian Plate, which encompasses almost the entire African continent, and smaller Somali Plate began pulling away from the Arabian Plate. Over the years, the two tectonic plates have been drifting apart, causing the rift to widen. Geologists believe that in about 50 million years, the Somali Plate, which includes nearly half of the East coast of Africa will completely break away from the Nubian Plate, forming a mini-continent, about the size of New Zealand, in the Indian Ocean.

Image Credit: Google Maps

Scientists are divided over the cause of the most recent crack. Its location along the Somali Plate has led some experts to speculate that it was caused by seismic activity, providing further validation of Africa’s eventual breakup. However, others are not sure. There were no earthquakes reported in the area, and a closer look at the images and videos of the fissure indicates the crack does not have the same outline, which means it would not fit like a puzzle if put back again. The crack is also not continuous, and the land on either side is flat, providing further evidence of the absence of tectonic activity. They therefore believe the chasm was the result of the inclement weather.

While many experts support the rainstorm theory, they are divided over how long the opening has been around. Ben Andrews, a geologist from the Smithsonian, thinks the chasm was created “hundreds of thousands of years” ago by tectonic plate movement, while the Kenya Geological Survey believes the opening is gullies created by groundwater. Both agree that the crack was revealed when the top layer of volcanic ash was washed away by the recent rain.

Photo Credit: CitizenTV Kenay via Twitter

Then there are those who believe the crack is entirely new. “I think it’s an Earth fissure, the same sort of thing that you see in Arizona after heavy rainstorms,” said earthquake geologist Wendy Bohon. “They’re the result of heavier torrential rains that come and wash away large portions of the dirt in the ground...It wasn’t a result of tectonics; it was the result of the weather.” While researchers puzzle over the rift’s cause, residents are keeping a close eye on the ground, hoping there are no further surprise cracks in store for them.

Resources: National,,,

Generate citations in MLA, APA & Chicago formats for this article.

VocabularyPlay Game


Reading Comprehension (7 questions)

  1. What happened in Kenya in mid-March?
  2. How big is the crack?

Critical Thinking Challenge

How would finding the crack’s cause help local...


Vocabulary in Context

“Scientists are divided over the cause of the most recent crack. Its location along the Somali plate has led some experts to speculate that it was caused...

Sign in to use your custom avatar.
  • btd5wyattFriday, August 10, 2018 at 1:30 pm
    that poor guy had to take apart his house by hand! watch the video to hear
    • elvernTuesday, July 3, 2018 at 5:12 pm
      i hope everyone is okay and this is cool
      • mopMonday, June 25, 2018 at 9:47 am
        that is insane guys hope they are okay
        • 12345678910Thursday, June 21, 2018 at 6:15 pm
          That is sad
          • pywyxuvugupuwe
            pywyxuvugupuweThursday, June 21, 2018 at 9:48 am
            it is called sadness
            • bunnieicecream
              bunnieicecreamSunday, June 17, 2018 at 2:53 pm
              That's cool but scary and dangerous
              • bunnieicecream
                bunnieicecreamSunday, June 17, 2018 at 2:52 pm
                will pray for everyone🙏
                • GlitzSpeedFriday, June 15, 2018 at 12:44 pm
                  Wow very scientific and scary if it happened next to my home.
                  • deadpoolTuesday, June 12, 2018 at 11:19 am
                    hope everone is ok
                    • applemango
                      applemangoSaturday, June 9, 2018 at 9:57 pm
                      I hope everyone is safe but this is amazing!!!

                      Recent Comments

                      Z wrote:

                      That was interesting.
                      Researchers May Have Finally Fig...

                      Bts for days wrote:

                      the calf rest in peace
                      Grieving Salish Sea Orca Whale C...

                      A-A-A wrote:

                      Also this is a genius
                      These Quirky-Looking Glasses Pro...

                      A-A-A wrote:

                      Ok so what happens if I already ...
                      These Quirky-Looking Glasses Pro...

                      Our Apps and Plugins