# The Mysterious Disappearance and Return of the Mediterranean Sea
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Chapter 1: An Iconic Landmark
The Mediterranean Sea stands as a symbol of historical significance. This remarkable body of water connects to the Atlantic Ocean and is encircled by the Mediterranean Basin, making it almost entirely landlocked—except for the narrow Strait of Gibraltar, which separates Morocco from Spain and links the Mediterranean with the Atlantic. To the south, it is bordered by North Africa, while Western and Southern Europe lie to the north, and the Levant is positioned to the east.
Historically, the Mediterranean served as a vital trade route, and understanding its history is crucial to interpreting the surrounding regions. For instance, the Romans held dominion over this sea for centuries, and their naval control was essential to their empire's power. While tales of Atlantis captivate the imagination, the Mediterranean's true disappearance is a documented phenomenon that transpired during the Mesozoic era, approximately 252.2 million years ago, lasting around 630,000 years.
Chapter 2: The Ice Age Theory
Photo by Rostyslav Savchyn on Unsplash
Several theories have emerged regarding the Mediterranean's disappearance. The first theory arose with the discovery of significant salt deposits in the sea, the largest globally, indicating that much of its water had evaporated at some point in history. This finding was not entirely surprising, given that the Mediterranean primarily receives water from the Atlantic through the Strait of Gibraltar, with only a minimal contribution from a few rivers.
One hypothesis suggested that a major cooling event during the Mesozoic era triggered an ice age, leading to the accumulation of water in glaciers and freezing conditions in the Atlantic. This scenario would have blocked or frozen the Strait of Gibraltar, cutting off the Mediterranean's water supply and causing it to dry up. However, this theory faced skepticism due to a lack of climatic evidence supporting an ice age during that period.
Chapter 3: The Tectonic Plates Theory
Tectonic Plates | Photo Credits: Pinterest
The tectonic plates theory posits that when the northwest corner of Africa collided with Iberia, it uplifted the Betic-Rif mountain ranges across southern Iberia and northwest Africa. This geological activity created two marine corridors, the Betic and Rifian, which gradually closed the gap between Morocco and Spain, effectively blocking the Atlantic's connection to the Mediterranean. Over time, this phenomenon drastically limited the Mediterranean’s water supply.
Coupled with climatic changes and rising temperatures, this situation led to the sea drying up to the point where marine life could not survive. Most species perished, explaining the absence of native marine organisms in the Mediterranean today. Interestingly, this event also allowed animals like hippos and elephants to migrate between Africa and Europe. The drying of the sea is known as the Messinian Salinity Crisis (MSC).
Chapter 4: Effects of the Messinian Salinity Crisis (MSC)
The MSC had profound impacts on the entire Mediterranean region. Most oceanic salt accumulated in the Mediterranean basin, leading to a reduction in the average salinity of the world’s oceans and increasing their freezing points. The crisis also diminished the biodiversity of the basin, as most species could not withstand the high salinity levels. The low altitude of the basin caused extreme heat during summer due to adiabatic heating, further worsening the environmental conditions.
Chapter 5: The Rebirth of the Sea
Photo Credits: Firmm
Ultimately, the Strait of Gibraltar was reopened due to the pressure from the Atlantic Ocean and some minor tectonic movements. This event was expected to create the largest waterfall in history, surpassing even Angel Falls and Niagara Falls. However, geological formations beneath Gibraltar slowed down the flow, resulting in a gradual refilling of the desiccated Mediterranean. This event, known as the Zanclean flood, is considered one of the most significant floods in history, replenishing the Mediterranean Sea to its former levels.
Chapter 6: Dwarfism and Gigantism in Isolated Species
The Mediterranean's disappearance and subsequent reappearance led to the isolation of several species from their original habitats. Insular dwarfism occurs when larger species shrink in size in new environments, while insular gigantism refers to smaller species growing larger. This phenomenon, known as Foster’s rule, is exemplified by the giant tortoises of the Galapagos, Seychelles, and Mascarene islands.
In contrast, island dwarfism can be seen in the endangered dwarf foxes of California's Channel Islands. Research suggests that the ancestors of these foxes, which were larger grey foxes, colonized the islands around 9,000 years ago, possibly through rafting or human introduction. These foxes weigh only 1 to 3 kilograms (approximately 2 to 7 pounds) and are among the few land mammals found on these islands. According to scholars, the dwarfism of these foxes may have occurred in as little as 2,000 years, as evidence from archaeological sites shows that their bones were already smaller than those of their mainland relatives.