[Rockhounds] A tectonic plate may have peeled apart—and that could shrink the Atlantic Ocean

[Kreigh Tomaszewski]

For years, João Duarte has puzzled over a seemingly boring underwater
expanse off the coast of Portugal. In 1969, this site spawned a massive
earthquake that rattled the shore and sparked a tsunami. But you would
never know why just from looking at the broad, featureless surface of the
seabed. Duarte, a marine geologist from the Instituto Dom Luiz at the
University
of Lisbon <http://idl.campus.ciencias.ulisboa.pt/profiles/joao-duarte/>,
wanted to find out what was going on.

Now, 50 years after the event, he may finally have an answer: The bottom of
the tectonic plate
<https://www.nationalgeographic.com/science/earth/the-dynamic-earth/plate-tectonics/>
off
Portugal's coast seems to be peeling away from its top. This action may be
providing the necessary spark for one plate to start grinding beneath
another in what's known as a subduction zone, according to computer
simulations Duarte presented in April at the European Geosciences Union
meeting <https://meetingorganizer.copernicus.org/EGU2019/orals/32205>.

If confirmed, the new work would be the first time an oceanic plate has
been caught in the act of peeling—and it may mark one of the earliest
stages of the Atlantic Ocean shrinking, sending Europe inching toward
Canada as predicted
<https://www.researchgate.net/publication/308875298_The_future_of_Earth's_oceans_consequences_of_subduction_initiation_in_the_Atlantic_and_implications_for_supercontinent_formation>by
some models
<https://www.researchgate.net/publication/326635536_Back_to_the_future_Testing_different_scenarios_for_the_next_supercontinent_gathering>
of
tectonic activity. (Find out what scientists think will happen when Earth's
tectonic plates grind to a halt.
<https://www.nationalgeographic.com/science/2018/08/news-happens-plate-tectonics-end-earth-mountains-volcanoes-geology/>
)

https://www.nationalgeographic.com/science/2019/05/tectonic-plate-peeled-apart-could-shrink-atlantic-ocean-geology/