In the foothills of southern Italy's iconic Aspromonte Mountains, University of Oregon geologist Becky Dorsey wields a foot-long hammer and gazes at the sea below. Sunbeams gleam off the blue waters of the Strait of Messina separating Sicily from Calabria, the toe of Italy's boot.
Dorsey pounds a steel tube into the cliffside then pulls out a cylinder of sand that holds clues to the region's past. By bucking scientific convention, she seeks to understand the processes that build mountains in this seismically active region, with implications for better understanding earthquake hazards in Italy.
"Calabria is a living laboratory," Dorsey said. "It's one of the most seismically active regions in the Mediterranean, plus we already know a great deal about its history and geology. That potent combination makes it ideal for research."
In May 2025, a UO-led research team collected 10 sand samples from marine terraces in Calabria. Those stair-step formations are created when ocean waves erode bedrock to carve out a flat platform, which tectonic activity pushes up to form a geological staircase rising above the ocean.
Marine terraces are also common along the West Coast of the U.S. where, as in Italy, they're being nudged up by tectonic activity that creates the stairsteps - and earthquakes. Unlike most of the regions scientists have studied, the terraces in Calabria were formed from one continuous, shallow marine shelf.
Dorsey's findings offer compelling evidence that the Calabrian terraces are rising 5 to 10 times faster than previously thought, which sheds light on the likely cause: a dense ocean slab tearing off the colossal tectonic plate miles below.
Understanding slab detachment could help scientists better understand fault slip rates and seismic hazards in Italy and other subduction zones where this process is active.
"The most important outcome of this research might be a message to reevaluate seismic hazards, because these faults in Italy appear to be slipping much faster than we previously thought," Dorsey said. "There may be less time before the next sequence of major earthquakes."
This view from southern Italy's Aspromonte Mountains shows Mt. Etna in Sicily across the Messina Strait and, at left, one of the high-elevation marine terraces pushed up by tectonic activity that Dorsey and her team sampled.
Unconventional research
Dorsey charted a bold scientific course, taking geological samples from spots that previous researchers had not considered viable for luminescence dating, the method used by her team to gauge the ages of the terraces.
In shallow coastal waters, ocean waves churn the sand, exposing the minerals to sunlight that bleaches the grains. When a layer of sand gets buried by sediment, the sunlight is blocked and crystals in the sand begin accumulating energy in the form of trapped electrons generated by background radiation. Scientists call this the burial age.
Luminescence dating estimates the burial age by measuring how much energy has accumulated in the sand grains. That date also tells us that uplift of the marine terrace started sometime after the sediments were deposited and buried.
The luminescence method is typically viable only for deposits younger than approximately 200,000 to 400,000 years old because crystals in the sand can only hold so many trapped electrons. The prevailing assumption is that the higher elevation terraces are too old for this method to work, so previous studies did not attempt it.
After carefully wrapping the tubes of sand to prevent light exposure, the UO-led research team shipped their samples to the University of Texas at Arlington, where assistant professor Nathan Brown conducted luminescence dating tests. Brown is a specialist in the procedure.
Their unorthodox approach paid off. The terraces turned out to be much younger than most prior studies concluded. To get to their current elevation, they must have been pushed up faster than what most scientists believed. The findings were published in the Nov. 6, 2026 edition of Communications Earth and Environment.
Dorsey's discoveries offer fresh insights into what's happening in the belt of faults that spans more than 100 miles in southern Italy. Tectonic activity has long shaped Calabria's topography, which continues to evolve as powerful forces below shape the landscape above.
Unearthing the layers
An outer crust approximately 25-miles thick contains all known life on Earth, but just 1% of its mass. Beneath that, a rocky mantle some 1,800 miles deep contains 84% of our planet's volume.
In the zone where those two layers intersect, the lithosphere makes up massive tectonic plates that drift, collide, splinter and slide. The motion of tectonic plates causes volcanic eruptions, earthquakes and warping on the earth's surface.
Dorsey is fascinated with how all that action below affects things happening at the surface. Her work includes studying the tectonics of Southwest Oregon, collaborating with biologists in Baja California and reconstructing the origins of the Colorado River. Dorsey's research has taken her to Taiwan, Mexico and throughout the western U.S. UO students have joined her to explore the Oregon Coast, the Cascade Mountains and western Idaho.
A slab off the old block
Dorsey's discoveries make a compelling case for what she believes caused Calabria's marine terraces: A segment of the African tectonic plate that sits beneath Italy is tearing off beneath the Eurasian plate in the Mediterranean.
If the terraces are rising as fast as her data indicate, conventional theories for southern Calabria will need to be reassessed.
The slab-tear hypothesis can explain the fast rate at which the marine terraces are rising, which geologists called uplift, Dorsey said. Uplift can be caused by several known mechanisms, including when the shallow part of a tectonic slab tears off and rises because it's buoyant.
She likened the phenomenon to holding a piece of cork underwater, cutting off a chunk and letting that smaller piece pop up to the surface. The broken piece of slab floats up quickly.
"It's remarkable to see that geological cork while it's rapidly rising," Dorsey said. "There are maybe one or two other places on Earth where we can catch this process in the act."
Clues for Oregon earthquakes
For the future, Dorsey hopes her new results will be tested, verified and plugged into seismic hazard models used by earthquake scientists. Any data that improves earthquake hazard assessment could save lives, Dorsey said.
The stakes of seismic hazard estimates are tangible in southern Italy, where plans are underway for a 2-mile, $16 billion bridge from Sicily to the mainland, crossing active faults.
Dorsey added that her published research offers an important reminder for scientists and students alike: No matter how much you think is known about a region or a problem, don't be afraid to go back to fundamentals and question the status quo.
"It's important to stay curious, keep an open mind and go where the data leads you," Dorsey said. "Then see what happens."
