How do submerged continents form?

Submerged landmasses like Zealandia form through tectonic processes when continental crust breaks away from a larger supercontinent and subsequently subsides beneath the ocean. For example, Zealandia broke away from Gondwana tens of millions of years ago and eventually became largely submerged beneath the Pacific Ocean. While some historical lost continents like Lemuria were disproven by modern plate tectonics, scientific simulation software has helped discover and confirm real sunken lands like Greater Adria.

What we know

• Zealandia is an almost entirely submerged mass of continental crust that subsided after breaking away from Gondwana 83 to 79 million years ago. [2]
• By about 23 million years ago, the Zealandia landmass may have been completely submerged, and today roughly 94% of it remains beneath the Pacific Ocean. [2]
• The development of plate tectonic simulation software has enabled the discovery and scientific confirmation of new lost lands such as Greater Adria. [4]
• Hypothetical sunken landmasses like Lemuria were originally proposed to explain animal fossil distributions before being discredited by plate tectonics. [3]

Where to go next

• what caused itWhat was Gondwana and how did it break apart?
• how it workedHow does plate tectonic simulation software discover lost lands?
• how we knowWhat evidence do geologists use to classify Zealandia as a continent?
• compared withHow does Greater Adria compare to Zealandia as a submerged landmass?
• the bigger pictureWhat are microcontinents and continental fragments?
• an unexpected connectionWhy was a sunken continent once proposed to explain lemur fossils?Zoologists originally hypothesized the sunken continent of Lemuria purely to solve a biological puzzle regarding animal migration before plate tectonics provided the real answer.

Sources

• [1]Zealandia (Wikidata Q150408) · CC0 1.0
• [2]Zealandia · CC BY-SA 4.0
• [3]Lemuria · CC BY-SA 4.0
• [4]Lost lands · CC BY-SA 4.0
• [5]Yonaguni Monument · CC BY-SA 4.0