Self-Motivation
David Goggins
Former Navy Seal
Career Development
Bryan Cranston
Actor
Critical Thinking
Liv Boeree
International Poker Champion
Emotional Intelligence
Amaryllis Fox
Former CIA Clandestine Operative
Management
Chris Hadfield
Retired Canadian Astronaut & Author
Learn
from the world's big
thinkers
Start Learning

Greater Adria, a lost continent hiding in plain sight

Most of it was eaten by Earth's mantle, but scraped-off bits survive in the Alps and other mountain ranges.

Greater Adria, science's newest lost continent, tore off from North Africa and was subducted beneath Southern Europe.

Image: Utrecht University
  • Following a 10-year survey, geologists discover a lost continent in the Mediterranean.
  • 'Greater Adria' existed for 100 million years, and was probably "great for scuba diving".
  • Most of it has been swallowed up by Earth's mantle, but bits of it survive.

Complex geology

Topographic map of the Mediterranean Sea basin, once home to the continent of Greater Adria.

Topographic map of the Mediterranean Sea basin, once home to the continent of Greater Adria.

Image: NASA / public domain

Move over, Atlantis. Not all lost continents are myths; here's one whose existence has just been verified by science. Greater Adria broke off from North Africa 240 million years ago. About 120 million years later, it started sinking beneath Southern Europe. But bits of it remain, scattered across local mountain ranges.

It's the geological similarities in those mountains that had led scientists to hypothesize the presence of an ancient continent in the Mediterranean. But the region's geology is so complex that only recent advances in computing—and a 10-year survey by an international team of scientists—were able to produce a geo-historical outline of that former land mass. This is the very first map of the world's latest lost continent (1).

The 100-million-year history of Greater Adria starts nearly a quarter of a billion years ago. The world was a very different place back then. It was just recovering from the Permian-Triassic extinction, which came pretty close to wiping out all life on Earth. The planet was repopulated by the first mammals and dinosaurs.

Supercontinental break-up

All together now: the supercontinent of Pangaea (335-175 million years ago).

All together now: the supercontinent of Pangaea (335-175 million years ago).

Image: Kieff / GFDL 1.2

Oblivious that biological imperative, Earth's geology was on a course of its own: fragmentation. At that time, the planet's land masses had coagulated into a single supercontinent, Pangaea.

Around 240 million years ago, a Greenland-sized piece of continental plate broke off from what would become North Africa and started drifting north. Between 120 and 100 million years ago, the continent smashed into Southern Europe. Even though the speed of that collision was no more than 3 to 4 cm per year, it ended up shattering the 100-km thick crust.

Most of the continental plate was pushed under Southern Europe and swallowed up by Earth's mantle, a process known as subduction. Seismic waves can still detect the plate, now stuck at a depth of up to 1500 km.

But some of the sedimentary rocks on top were too light to sink, so they were scraped off and got crumpled up—the origin of various mountain chains across the Mediterranean region: the Apennines in Italy, parts of the Alps, and ranges in the Balkans, Greece and Turkey.

Death and birth

Flowing from present to deep past, this time-lapse reconstruction of the geological history of the Mediterranean shows the death and birth (in that order) of Greater Adria in unprecedented amounts of detail.

Some bits of Greater Adria survived both the shave-off into mountainhood and death by subduction. "The only remaining part of this continent is a strip that runs from Turin via the Adriatic Sea to the heel of Italy's boot," says Douwe van Hinsbergen, Professor of Global Tectonics and Paleogeography at Utrecht University, and the study's principal researcher. That's an area geologists call 'Adria', so the team, consisting of scientists from Utrecht, Oslo and Zürich, called the lost continent 'Greater Adria'.

What was the continent like? A shallow continental shelf in a tropical sea, where sediments were slowly turned into rock, Greater Adria possibly resembled Zealandia, a largely submerged continent with bits sticking out (i.e. New Zealand and New Caledonia), or perhaps the Florida Keys, an archipelago of non-volcanic islands. Either way, dotted with islands and archipelagos above the water, and lots of coral below, it was "probably good for scuba diving," Van Hinsbergen says.

It took scientists this long to produce the first map of Greater Adria not just because the Mediterranean is, in the words of Van Hinsbergen, "a geological mess (…) Everything is curved, broken and stacked. Compared to this, the Himalayas represent a rather simpler system." Greater Adria perished by subduction and scraping-off. The Himalayas emerged by the collision of two continents.

Ore deposits

A reconstruction of Greater Adria, Africa and Europe about 140 million years ago. In lighter green, submerged parts of continental shelves.

A reconstruction of Greater Adria, Africa and Europe about 140 million years ago. In lighter green, submerged parts of continental shelves.

Image: Utrecht University

The region also has a complex geopolitical makeup, obliging the researchers to piece together evidence from 30 different countries, from Spain to Iran, "each with its own geological survey, own maps, own ideas about evolutionary history. Research often stops at national borders."

So what has geology learned from the discovery of Greater Adria?
  • First off, that its hypothesis was right: Geological similarities across the Mediterranean really did point to a lost continent, now found.
  • Secondly, the reconstruction of Greater Adria has also taught geologists that subduction is the basic way in which mountain belts are formed.
  • They've also learned a great deal about volcanism and earthquakes, and "(we) can even predict, to a certain extent, what a given area will look like in the far future," van Hinsbergen says.
  • Finally, and practically, these insights will help scientists and surveyors to identify and locate ore deposits and other useful materials in mountain belts.

Strange Maps #994

Greater Adria map and movie reproduced with kind permission of Utrecht University.

The article 'Orogenic architecture of the Mediterranean region and kinematic reconstruction of its tectonic evolution since the Triassic', by Van Hinsbergen e.a., appeared in the latest issue of Gondwana Research (September 2019).

Got a strange map? Let me know at strangemaps@gmail.com.

(1) There are plenty of these to go around: mythical ones like Atlantis, Mu, Lemuria and Kumari Kandam; and real ones from geological history like Avalonia, Congo Craton, Kalaharia and Laurentia.

Remote learning vs. online instruction: How COVID-19 woke America up to the difference

Educators and administrators must build new supports for faculty and student success in a world where the classroom might become virtual in the blink of an eye.

Credit: Shutterstock
Sponsored by Charles Koch Foundation
  • If you or someone you know is attending school remotely, you are more than likely learning through emergency remote instruction, which is not the same as online learning, write Rich DeMillo and Steve Harmon.
  • Education institutions must properly define and understand the difference between a course that is designed from inception to be taught in an online format and a course that has been rapidly converted to be offered to remote students.
  • In a future involving more online instruction than any of us ever imagined, it will be crucial to meticulously design factors like learner navigation, interactive recordings, feedback loops, exams and office hours in order to maximize learning potential within the virtual environment.
Keep reading Show less

Octopus-like creatures inhabit Jupiter’s moon, claims space scientist

A leading British space scientist thinks there is life under the ice sheets of Europa.

Jupiter's moon Europa has a huge ocean beneath its sheets of ice.

Credit: NASA/JPL-Caltech/SETI Institute
Surprising Science
  • A British scientist named Professor Monica Grady recently came out in support of extraterrestrial life on Europa.
  • Europa, the sixth largest moon in the solar system, may have favorable conditions for life under its miles of ice.
  • The moon is one of Jupiter's 79.
Keep reading Show less

White dwarfs hold key to life in the universe, suggests study

New study shows white dwarf stars create an essential component of life.

White dwarfs.

NASA and H. Richer (University of British Columbia)
Surprising Science
  • White dwarf stars create carbon atoms in the Milky Way galaxy, shows new study.
  • Carbon is an essential component of life.
  • White dwarfs make carbon in their hot insides before the stars die.
Keep reading Show less

"Forced empathy" is a powerful negotiation tool. Here's how to do it.

Master negotiator Chris Voss breaks down how to get what you want during negotiations.

Juan Carlos Correa (L) , a prospective home buyer is shown a short sale home by Denise Madan, a Real Estate agent with Re/Max, as he shops for a house on April 22, 2014 in Coral Gables, Florida.

Photo by Joe Raedle/Getty Images
Personal Growth
  • Former FBI negotiator Chris Voss explains how forced empathy is a powerful negotiating tactic.
  • The key is starting a sentence with "What" or "How," causing the other person to look at the situation through your eyes.
  • What appears to signal weakness is turned into a strength when using this tactic.
Keep reading Show less
Scroll down to load more…
Quantcast