Buildings in the ancient coastal city of Alexandria are being destroyed at an ever-increasing rate by rising sea levels. (Photo credit: Tuul and Bruno Morandi/Getty Images)
Researchers have found that the historic Egyptian city of Alexandria is being destroyed by rising sea levels.
The rate of collapse of buildings along the ancient city's waterfront has increased from one to 40 cases per year over the past decade, according to a study published Feb. 12 in the journal Earth's Future.
Over the past two decades, 280 structures in this 2,300-year-old port city, known as the birthplace of Cleopatra and the ancient home of the famous Library of Alexandria, have collapsed due to coastal erosion, and another 7,000 are at risk of collapse in the future, the article states. Between 2014 and 2020, 86 buildings completely collapsed and 201 partially collapsed across the city, causing 85 deaths.
“The true cost of this loss goes far beyond bricks and mortar,” study co-author Essam Heggie, a water resources specialist at the University of Southern California’s Viterbi School of Engineering, said in a statement. “We are witnessing the gradual disappearance of historic coastal cities, and Alexandria is sounding the alarm. What once seemed like distant climate threats are now real.”
Coastal building collapse is caused by rising sea levels and the subsequent infiltration of seawater into the soil beneath the city. As saltwater infiltrates further inland due to rising sea levels, it raises the water table beneath buildings and other infrastructure and erodes the soil. This can cause the ground to subside, making buildings unstable and at risk of collapse. Saltwater also erodes the steel reinforcement of building foundations, further weakening the structures.
Alexandria is a port city located on the Mediterranean coast, making it susceptible to seawater intrusion.
According to the National Oceanic and Atmospheric Administration (NOAA), the average global sea level has risen 8 to 9 inches (20 to 23 centimeters) since 1880, and 4 inches (10 centimeters) since 1993. Without action to curb climate change, sea levels in the United States could rise 7.2 feet (2.2 meters) by 2100 compared to 2000 levels.
Low-lying cities, especially those along the U.S. East and West Coasts and the Gulf Coast, are at greatest risk from erosion and flooding from rising sea levels, according to NASA.
“Our study challenges the common misconception that we only need to worry when sea levels rise
Sourse: www.livescience.com
