An oceanic plate dives beneath another in an illustration of a subduction zone. Studies of tectonic activity off the coast of Portugal may reveal a new subduction zone being born.
Something strange is happening off the coast of Portugal, and scientists have now proposed a groundbreaking explanation.
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, 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 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