Why is it in the News?

The Israel Geological Survey announced recently that Israeli geologists discovered a huge underwater canyon on the bottom of the Eastern Mediterranean that was formed about 6 million years ago.

What is Messinian Event?

• The Messinian Event, also referred to as the Messinian Salinity Crisis (MSC).
• It marks a significant geological occurrence during which the Mediterranean Sea experienced a cycle of partial or near-complete desiccation, making it one of the most severe ecological crises in Earth's history.
• This event unfolded approximately 6 million years ago (MYA) and persisted until around 5.3 MYA.
• The process began with the severance of the connection between the Atlantic Ocean and the Mediterranean Sea.
  • This disconnection resulted from a combination of reduced sea levels globally and the collision of the European and African plates, causing the land to rise.
  • Consequently, the Mediterranean experienced significant evaporation, as its evaporation rate exceeded its precipitation rate.
  • Without a substantial influx of water from the Atlantic, the sea began to evaporate rapidly.
• During this period, a vast underground canyon formed, with rivers cutting deep into the basin floor, creating a canyon much larger than the Grand Canyon, reaching depths of up to 2,000 meters (6562 feet).
  • As the Mediterranean water evaporated, salt deposits, primarily composed of Halite and Gypsum, accumulated on the basin floor, some reaching depths of 800 meters (2,500 feet).
• Despite the rapid evaporation, salt deposition did not keep pace, resulting in an increase in water salinity.
  • The heightened salinity levels made the Mediterranean inhospitable to marine life, leading to a decline in biodiversity.
  • Eventually, the sea dried up almost entirely, culminating in the Zanclean flood when the Atlantic Ocean reclaimed the basin.

What is Deep-sea Canyon?

• Deep-sea canyons, such as those formed during the Messinian Event, are steep valleys carved into the seafloor of the continental slope, extending onto the continental shelf.
• These canyons vary in size and shape and have been sculpted by various erosional processes, including river flows during periods of low sea levels, mudslides, debris flows, and turbidity currents.