A new method to fight coastal erosion: Researchers at Northwestern University have pioneered a new method to combat coastal erosion by using electrical currents to solidify marine sand, according to a study (pdf). The approach creates durable, rock-like structures that could replace traditional, costly coastal defences such as sea walls.

How does it work? The team utilized naturally occurring dissolved minerals in seawater to form a natural cement between sand grains and employed electrical energy to trigger the chemical reaction. Laboratory experiments demonstrated that a mild electrical current could transform marine sand into a solid, immovable structure.

Why does this matter? As temperatures and sea levels rise due to climate change, rocky coasts are receding at a rapid pace unseen for the past 3-5k years, according to Imperial College London research. Erosion of rocky coasts — expected to reach 3-7 times today’s rate and push coast cliffs 10-22 meters inland — is irreversible. While coastal erosion is a natural process dictated by sea levels, sediment transport, waves, and storm surges, amongst other factors, it is currently being exacerbated by climate change, according to a study (pdf) published in Heliyon journal.

The new method is cheaper than conventional ones: Traditional methods to mitigate erosion, such as building sea walls or injecting cement, are expensive and often short-lived, the study explains. The new method, which uses naturally dissolved minerals, creates a stronger and more durable solution than conventional methods. It’s also cost-effective, estimated at just USD 3-6 per cbm, compared to up to USD 70 per cbm for traditional methods.

Tunisia could benefit from the tech: Tunisian seaside town Hammemet is suffering from severe coastal erosion due to human interference — such as construction, property development, and offshore sand mining — disrupting the natural cycle of sedimentation, AFP reported (watch runtime: 2:19). Sediment is effectively blocked from traveling and depositing along the coastline which speeds up erosion as beaches lack an influx of new material. Over 90 km of Tunisia’s beaches are suffering from the phenomenon.

What’s next? The next phase of the research will be to test the method on beaches outside of the lab. The team hopes it can be used to reinforce protection structures, marine foundations, and more.

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