Wednesday 3 January 2024

The Arid Lands themes: The Messinian Salinity Crisis

My newly released SF novel, The Arid Lands is set some 600 years from now, in an alternate future when the Mediterranean has almost completely dried out. It is in this inhospitable landscape of salt flats and occasional pools of hypersaline brine that Inez and her people struggle to survive. Inez knows no other existence. But all that is about to change.

You may think that the idea of a vast sea such as the Mediterranean almost completely evaporating is pure fiction, but let me tell you, it is not. For the Mediterranean Sea did indeed dry out, albeit a long time ago.

About 6 Million years ago (Ma) the Mediterranean Sea became disconnected from the Atlantic Ocean. During the period that followed, known as the Messinian Salinity Crisis the sea almost completely evaporated.

The closing of the connections between the Mediterranean and the Atlantic Ocean, which is now the Straits of Gibraltar, was caused by the shifting tectonics in this region. This isolation of the Mediterranean from the main inflow happened several times, between 6 and 5.3 Ma.

The initial phase was one of repeated cycles of evaporation and replenishment which led to the formation of thick sequences of evaporite deposits, minerals such as halite and gypsum, deposited from the evaporating seawater.

The connection was then cut off for a prolonged period of time. During this later episode of desiccation, the Mediterranean became a dry basin, as much as 5 km deep, with only a few hypersaline pockets of water remaining. This process of drying out the Mediterranean Sea is estimated to have taken about 1000 years.

The Mediterranean remained dry until 5.3 Ma when the Straits of Gibraltar were finally breached, and water flooded back into the Mediterranean basin in the form of a cataclysmic flood, and so the Mediterranean Sea as we know it today was formed.

But the thick evaporite deposits and the presence of deep canyons in the seabed which cut down into the abyssal plains as water returned to the sea are testament to this arid phase in the Mediterranean Sea’s history.

This is the setting for The Arid Lands. A hostile environment that once really existed. I will talk more about this geological event and how it inspired the world I describe in The Arid Lands in future posts on this blog.

The Arid Lands is available from Amazon in both kindle and print format.

UK Link

US Link

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