The Great Rift: Africa’s Splitting Plates

In Context

• Scientists, in 2020, predicted a new ocean would be created as Africa gradually splits into two separate parts.

In news

• East African Rift:
  • The division of the continent is connected to the East African Rift, a crack that stretches 56 kilometres and appeared in the desert of Ethiopia in 2005.
  • The crack has triggered the formation of a new sea.
• Division of the continents:
  • This geological process will inevitably divide the continent, resulting in currently landlocked countries, such as Uganda and Zambia, obtaining their own coastlines in due time, which would take five to 10 million years according to the study.
  • As the Somali and Nubian tectonic plates continue to pull apart from each other, a smaller continent will be created from the rift, which will include present-day Somalia and parts of Kenya, Ethiopia, and Tanzania.
  • The Gulf of Aden and the Red Sea will eventually flood into the Afar region in Ethiopia and the East African Rift Valley, leading to the formation of a new ocean.
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Consequences

• Advantages:
  • On the upside, the emergence of new coastlines will unlock a myriad of opportunities for economic growth.
  • These countries will have access to new ports for trade, as well as fishing grounds and sub-sea internet infrastructure, which will undoubtedly transform their economic potential.

• Disadvantages:
  • Evacuation & displacement:
    • The necessary evacuation of people and the potential loss of lives will be an unfortunate cost of this natural phenomenon. 
    • As the plates continue to split in the future, this phenomenon will result in the displacement of communities, settlements and various flora and fauna.
      • Africa is the most impacted region when it comes to displacement, with a larger number of countries affected than any other continent or region.
      • As of 2015, more than 15 million people were internally displaced in Africa, according to the United Nations Environment Programme report on displacement and environment.
  • Environmental degradation:
    • These changes will impact their habitats due to climate change, resulting in environmental degradation. 
    • Rapid urbanisation and increased settlements will put pressure on natural resources, leading to a scarcity of water, energy and food.
  • Loss of biodiversity:
    • Furthermore, some species will disappear, while others will become endangered due to habitat changes.
  • Seismic activity & volcanism:
    • While the process of rifting may often go unnoticed, the separation of the Nubian and Somali plates can result in the formation of new faults, fissures and cracks or the reactivation of pre-existing faults, leading to seismic activity.
    • Additionally, the close proximity of the hot molten asthenosphere to the surface causes volcanism, further displaying the ongoing process of continental breakup.

Alternative theories of Continent formation

• The most commonly accepted theory in place attributes continent formation to the movement of tectonic plates.
• Earth is uncommon among the planets and also from our moon that its outer surface is divided into rigid slabs, which were called tectonic plates by Wegener in his theory. 
  • While their surfaces exhibit evidence of recent deformation, neither planet has a surface divided into plates.
• As the technology advanced, making it possible for deeper exploration, the theories of continental drift and seafloor spreading got positive scientific data in support.
  • The two theories were merged to develop the modern plate tectonic theory.

Plate Tectonic Theory/Plate Tectonic

• Plate tectonic theory had its beginnings in 1915 when Alfred Wegener proposed his theory of “continental drift. 
• According to the theory, Earth has a rigid outer layer, known as the lithosphere, which is typically about 100 km (60 miles) thick and overlies a plastic (moldable, partially molten) layer called the asthenosphere. 
• The lithosphere is broken up into:
  • seven very large continental- and ocean-sized plates,
  • six or seven medium-sized regional plates, and 
  • several small plates. 
• These plates move relative to each other.
  • They typically move at rates of 5 to 10 cm (2 to 4 inches) per year, and interact along their boundaries.
  • They converge, diverge, or slip past one another. 
  • Mountain formation:
    • Plate motions cause mountains to rise where plates push together or converge. 
  • Ocean formation:
    • Continents fracture and oceans are formed where plates pull apart or diverge.
• The continents are embedded in the plates and drift passively with them, which over millions of years results in significant changes in Earth’s geography.
• Such interactions are thought to be responsible for most of Earth’s seismic and volcanic activity, although earthquakes and volcanoes can occur in plate interiors.
• Evidence of Plate Tectonic Theory:

• Continent Puzzle:
  • The continents fit together almost like puzzle pieces forming Pangaea (one super-continent).
• Fossil evidence:
  • Fossils on different continents are similar to fossils on continents that were once connected.  
  • When the continents split, different life forms developed.
• Distributions of rocks:
  • Most distributions of rocks within Earth’s crust, including minerals, fossil fuels, and energy resources, are a direct result of the history of plate motions and collisions and the corresponding changes in the configurations of the continents and ocean basins.

Way ahead

• Rapid occurrences such as the sudden splitting faults may lend a sense of urgency to continental rifting, the process itself is extremely slow and can go unnoticed most of the time as it progressively splits Africa.
• Several planetary transformations are occurring, primarily as a result of climate change. Devastating weather patterns owing to global warming are altering landscapes and raising sea levels.
• Although human displacement is not new, climate change exacerbates gradual and abrupt environmental crises by increasing their intensity, frequency and scope.

Source: DTE