Atlantis appears in two philosophical discussions written by Plato in the 5^th century BC, Timaeus and Critias. But it was not until the penny dreadfuls and adventure stories of 19^th century Britain that people transferred Atlantis from a philosophical device to a discussion of a “real” city. While Plato was clearly using a fictional place for his argument, sunken cities from around Greece would have been known to him and would have acted as inspiration. For instance, Helike was sunk by a tsunami during Plato’s lifetime and it would have been big news. If Plato had sailed around southern Greece then he could have seen the half submerged ruins of Palvopetri, which was abandoned over 500 years before his lifetime. Given the prevalence of tectonic activity in the Mediterranean, ancient peoples would have known about sunken cities.

There is a lot to learn about the past from the cities discussed in this lesson. For instance, the excavations at Alexandria has led to incredible discoveries about life and trade in the ancient Mediterranean. UNESCO has compiled a report of sources and findings from Port Royal. The lagoon that formed over Helike silted up to form a delta, which is currently part of a large archaeological project. The BBC made a documentary on Pavlopetri and life in the Bronze Age, which you can watch here. Click and learn more! The British Museum has an exhibit called Sunken Cities: Egypt’s Lost Worlds that will run from May 19 to November 27, 2016.

The different mechanisms of submergence show us how dynamic our planet can be. Earthquakes are a major force behind cities’ submergence, whether from displacement, liquefaction, or tsunamis. You can learn more about the different hazards of earthquakes here. NOAA has a great website with resources about tsunamis. More information about isostatic sea level change can be found here

Another form of sea level change which was not discussed in the lesson is eustatic which differs from isostatic because its effect is global due to an increase in water in the world’s oceans. Eustatic sea level change mostly occurred between 19,000 years ago when the ice caps melted to 5,000 years ago when the water level reached equilibrium. Since most cities do not date older than 5,000 years ago, eustatic sea level change is not a common mechanism for submerging cities; however, settlements and other parts of life have been found in drowned landscapes dating to the periods prior to 5,000 years ago.

Nic Flemming is the pioneer of studying the changing earth through sunken cities. His book Cities in the Sea examines cities around the Mediterranean and the reasons behind their submergence. Flemming has published many academic articles, as well as the latest overview of land submergence in an EU paper that can be downloaded for free here. For submerged settlements even older than cities, see the book Submerged Prehistory. 

Want to find out more about underwater research? MaritimeArchaeology.com has resources and news from archaeologists. Interested in the sunken cities, shipwrecks, and underwater caves that the educator is working on? Check out this website to explore the projects that he directs around the world.