Discovery of ancient underwater landslide could help Middle Eastern nations realize tsunami hazards

Discovery of ancient underwater landslide could help Middle Eastern nations realize tsunami hazards

UM Rosenstiel School scientist Sam Purkis discovered evidence of a 500-year-old landslide, and a sizable tsunami, that could have implications for coastline development of coastlines in Egypt and Saudi Arabia.

MIAMI—An earth scientist from the University of Miami Rosenstiel School of Marine and Atmospheric Science discovered evidence of an ancient underwater landslide and associated tsunami in the Gulf of Aqaba, a subsidiary of the Red Sea, that should serve as a warning for many nations in the Middle East.

Sam Purkis, professor and chair of the Department of Marine Geosciences, spent four weeks aboard the OceanXplorer research vessel in the region. As he and a fellow scientist were ascending from 3,000 feet during a submersible dive, Purkis noticed a startling break in the seabed. It was an unexpected find, although not out of the question for the Red Sea, which was formed by the separation of the African and Arabian tectonic plates 30 million years ago.

“Immediately, I realized that what we were looking at was the result of some geological force, which had broken the seafloor,” said Purkis.

Purkis then began a scientific journey to learn more about the chasm, and took rock samples, which revealed that it had been created by a landslide that likely occurred 500 years ago. He was also able to find evidence from sediment collected north of the chasm, which showed that a tsunami was likely spawned by the landslide.

The study, “Tsunamigenic Potential of an Incipient Submarine Landslide in the Tiran Straits,” published February 3, 2022 in the journal Geophysical Research Letters of the American Geophysical Union (AGU),  predicts that future movement of the seabed might trigger more tsunami in the Gulf. Therefore, the nations along its coasts—including Egypt, Jordan, Saudi Arabia, and Israel—need to ensure that early warning systems are in place for both earthquakes and tsunami.

“Just a little shake in the wrong place and the whole wall could fail, leading to a much larger tsunami than occurred 500 years ago,” Purkis said. “That area of Egypt, as well as Saudi Arabia, which are urbanizing so rapidly, have certain hazards which haven’t been previously recognized, but they need to be, to avoid a future catastrophe.”

The entire OceanXplorer research voyage was funded by Neom, a company developing the Saudi Arabian coastline.

About the University of Miami

The University of Miami is a private research university and academic health system with a distinct geographic capacity to connect institutions, individuals, and ideas across the hemisphere and around the world. The University’s vibrant and diverse academic community comprises 12 schools and colleges serving more than 17,000 undergraduate and graduate students in more than 180 majors and programs. Located within one of the most dynamic and multicultural cities in the world, the University is building new bridges across geographic, cultural, and intellectual borders, bringing a passion for scholarly excellence, a spirit of innovation, a respect for including and elevating diverse voices, and a commitment to tackling the challenges facing our world. Founded in the 1940s, the Rosenstiel School of Marine and Atmospheric Science has grown into one of the world’s premier marine and atmospheric research institutions. Offering dynamic interdisciplinary academics, the Rosenstiel School is dedicated to helping communities to better understand the planet, participating in the establishment of environmental policies, and aiding in the improvement of society and quality of life. www.rsmas.miami.edu.