Lost Continents – December 4, 2019

Today’s topic is on lost continents. Sure, you’ve probably heard the myths. Atlantis? But what is scientific research telling us about new landmasses? How are we finding them? And what does it mean?

In the past few years, there’s been an increase in the discovery of “lost continents” due to more sophisticated mapping of the ocean floor and collection of more rock samples for chemical and mineralogical analysis from the depths. Most of these landmasses are plateaus or mountains made of continental crust (not volcanic rock) hidden from our view, below sea level. Take Zealandia, for example. At five million square kilometers (1.9 million sq miles), it is two thirds the size of neighboring Australia! Some researchers are making the case for it being considered our 8th continent.

Nearly 95% of that area is underwater with only a few islands and three major landmasses sticking out above the surface: New Zealand’s North and South Islands and New Caledonia.

According to researchers, being above water should not be the only component for being considered a continent, citing other factors like: elevation above the surrounding area, distinctive geology, a well-defined area and a crust thicker than the regular ocean floor.

Zealandia is fascinating given its size, its submersion and the fact that it’s unfragmented. Studying it, and other landmasses like it, can reveal much more about how continental crust forms and breaks up. This, in turn, reveals much more about how our planet works (the past, present and future). There are still discoveries out there to be made!

#sciencewednesdays#summitssongsandscience

image: “The World – Australia” by National Geospatial-Intelligence Agency is licensed under CC PDM 1.0