Tectonic plates are the reason we have earthquakes, volcanoes, oceans, and continents. Without them shifting around, breaking up, and making up so to speak, the surface of our planet would be dead and desolate. They’re as vital as the air we breathe – which is why it’s important we know where all of them are.
At school, you’re probably taught that these plates are terrifically huge, and the Pacific Plate, the North American Plate, and even the delightfully named Juan de Fuca Plate probably come up. A new study, published in the journal Geophysical Research Letters, reminds us all that we don’t actually know where all of the planet’s tectonic plates are, or even how many there are.
A team of geophysicists led by Rice University have identified the Malpelo Plate, the 57th tectonic plate and the newest of its kind in a decade. It’s topped by a small island, is linked to a nearby oceanic ridge, and is found off the coast of Ecuador, along the Ring of Fire. It’s wedged in-between the Nazca, Cocos, and Caribbean Plates.
Although there are nuances to it, a plate is essentially a part-crust, part-mantle beast that is pushed around by the convecting currents of superheated rock beneath them.
The largest ones, like the North American Plate, are quite easy to spot. Marked by enormous ocean ridges, volcanic ranges, or oceanic chasms, they can clearly be measured moving one way or the other at roughly the same speed – with some major caveats – all across their colossal breadth.
Smaller ones are a little trickier to see, as their movements are partly influenced by the more dominant massive ones. This was the case with the Malpelo Plate, which at first had to be detected indirectly.
The researchers noticed that the Pacific Plate, which butts up against the Cocos and Nazca Plates just west of the Galapagos Islands, appeared to be defying predictions of its movement across the plate ever so slightly. When analyzing the motions of all three, they concluded that something must be nudging them, but no such plate was described on any of the most cutting-edge submarine maps.
Scouring through a Columbia University database of sonar recordings, the team found that between the Galapagos Islands and the coast of Ecuador lay a telltale oceanic ridge. Putting all the pieces together, they realized that they had discovered a new tectonic plate.
Tantalizingly, their calculations also show that it’s not just the Malpepo Plate that’s giving the others a speed boost. Another still undiscovered plate in the region is bumping up against them too – but right now, they have no idea where it is.
The search for Plate 58 is now on.