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.

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.

Radical innovation: Unlocking the future of human invention

Ready to see the future? Nanotronics CEO Matthew Putman talks innovation and the solutions that are right under our noses.

Big Think LIVE

Innovation in manufacturing has crawled since the 1950s. That's about to speed up.

Keep reading Show less

Your body’s full of stuff you no longer need. Here's a list.

Evolution doesn't clean up after itself very well.

Image source: Ernst Haeckel
Surprising Science
  • An evolutionary biologist got people swapping ideas about our lingering vestigia.
  • Basically, this is the stuff that served some evolutionary purpose at some point, but now is kind of, well, extra.
  • Here are the six traits that inaugurated the fun.
Keep reading Show less

Quantum particles timed as they tunnel through a solid

A clever new study definitively measures how long it takes for quantum particles to pass through a barrier.

Image source: carlos castilla/Shutterstock
  • Quantum particles can tunnel through seemingly impassable barriers, popping up on the other side.
  • Quantum tunneling is not a new discovery, but there's a lot that's unknown about it.
  • By super-cooling rubidium particles, researchers use their spinning as a magnetic timer.

When it comes to weird behavior, there's nothing quite like the quantum world. On top of that world-class head scratcher entanglement, there's also quantum tunneling — the mysterious process in which particles somehow find their way through what should be impenetrable barriers.

Exactly why or even how quantum tunneling happens is unknown: Do particles just pop over to the other side instantaneously in the same way entangled particles interact? Or do they progressively tunnel through? Previous research has been conflicting.

That quantum tunneling occurs has not been a matter of debate since it was discovered in the 1920s. When IBM famously wrote their name on a nickel substrate using 35 xenon atoms, they used a scanning tunneling microscope to see what they were doing. And tunnel diodes are fast-switching semiconductors that derive their negative resistance from quantum tunneling.

Nonetheless, "Quantum tunneling is one of the most puzzling of quantum phenomena," says Aephraim Steinberg of the Quantum Information Science Program at Canadian Institute for Advanced Research in Toronto to Live Science. Speaking with Scientific American he explains, "It's as though the particle dug a tunnel under the hill and appeared on the other."

Steinberg is a co-author of a study just published in the journal Nature that presents a series of clever experiments that allowed researchers to measure the amount of time it takes tunneling particles to find their way through a barrier. "And it is fantastic that we're now able to actually study it in this way."

Frozen rubidium atoms

Image source: Viktoriia Debopre/Shutterstock/Big Think

One of the difficulties in ascertaining the time it takes for tunneling to occur is knowing precisely when it's begun and when it's finished. The authors of the new study solved this by devising a system based on particles' precession.

Subatomic particles all have magnetic qualities, and they spin, or "precess," like a top when they encounter an external magnetic field. With this in mind, the authors of the study decided to construct a barrier with a magnetic field, causing any particles passing through it to precess as they did so. They wouldn't precess before entering the field or after, so by observing and timing the duration of the particles' precession, the researchers could definitively identify the length of time it took them to tunnel through the barrier.

To construct their barrier, the scientists cooled about 8,000 rubidium atoms to a billionth of a degree above absolute zero. In this state, they form a Bose-Einstein condensate, AKA the fifth-known form of matter. When in this state, atoms slow down and can be clumped together rather than flying around independently at high speeds. (We've written before about a Bose-Einstein experiment in space.)

Using a laser, the researchers pusehd about 2,000 rubidium atoms together in a barrier about 1.3 micrometers thick, endowing it with a pseudo-magnetic field. Compared to a single rubidium atom, this is a very thick wall, comparable to a half a mile deep if you yourself were a foot thick.

With the wall prepared, a second laser nudged individual rubidium atoms toward it. Most of the atoms simply bounced off the barrier, but about 3% of them went right through as hoped. Precise measurement of their precession produced the result: It took them 0.61 milliseconds to get through.

Reactions to the study

Scientists not involved in the research find its results compelling.

"This is a beautiful experiment," according to Igor Litvinyuk of Griffith University in Australia. "Just to do it is a heroic effort." Drew Alton of Augustana University, in South Dakota tells Live Science, "The experiment is a breathtaking technical achievement."

What makes the researchers' results so exceptional is their unambiguity. Says Chad Orzel at Union College in New York, "Their experiment is ingeniously constructed to make it difficult to interpret as anything other than what they say." He calls the research, "one of the best examples you'll see of a thought experiment made real." Litvinyuk agrees: "I see no holes in this."

As for the researchers themselves, enhancements to their experimental apparatus are underway to help them learn more. "We're working on a new measurement where we make the barrier thicker," Steinberg said. In addition, there's also the interesting question of whether or not that 0.61-millisecond trip occurs at a steady rate: "It will be very interesting to see if the atoms' speed is constant or not."

Self-driving cars to race for $1.5 million at Indianapolis Motor Speedway ​

So far, 30 student teams have entered the Indy Autonomous Challenge, scheduled for October 2021.

Illustration of cockpit of a self-driving car

Indy Autonomous Challenge
Technology & Innovation
  • The Indy Autonomous Challenge will task student teams with developing self-driving software for race cars.
  • The competition requires cars to complete 20 laps within 25 minutes, meaning cars would need to average about 110 mph.
  • The organizers say they hope to advance the field of driverless cars and "inspire the next generation of STEM talent."
Keep reading Show less
Mind & Brain

The dangers of the chemical imbalance theory of depression

A new Harvard study finds that the language you use affects patient outcome.

Scroll down to load more…
Quantcast