Underwater tunnels to and from the Caspian?

From the times of Ptolemy’s Geographia, the Caspian Sea was (wrongly!) depicted by European cartographers as widest from east to west.  Only as late as 1647 did Adam Olearius manage to correct this mistake.  Click here to see Olearius’ map.

Elio Brancaforte has described Olearius as an intellectual hybrid: drawing on classical and biblical sources, but also drawing on his own (and local people’s) observations.  Olearius summarised the medieval / early modern idea of relying on predecessors rather than empirical evidence when he wrote “if one person makes a mistake, all the others do too”.

But just because one person was correct, others unfortunately continued to make errors. The Jesuit polymath Athanasius Kircher (1602-1680) was widely regarded as the physical embodiment of all the learning of his age, a scientific superstar, and the last true Renaissance man – but his world map in 1665 again reproduced the Ptolemaic shape for the Caspian.

More interestingly, Kircher’s map theorized massive tunnels and a huge and complex interchange of water flows between the Caspian Sea, the Black Sea, and the Persian Gulf.  www.geographicus.com have kindly allowed me to include a small version of the Kircher map – but please do click and zoom here to see the abysses and tunnels in the Caspian.

Kircher didn’t rely for his ideas on anyone else – he had a fascinating (if wrong!) hydrogeographic theory that tides and ocean currents are caused by water moving to and from a massive subterranean ocean, via huge abysses.  His 1665 map shows the abysses and the currents they create as well as the world’s known volcanoes.