Maranhão City Sees Ocean Advance Inland

In São Domingos do Maranhão, Brazil, ocean tides surge kilometers inland, creating waves within the forests. This unusual phenomenon occurs due to the funneling of water in the Gulf of Maranhão, elevating waves from equinoctial tides. The resulting “pororoca” wave travels through rivers and channels, reshaping the landscape and allowing surfers to ride within the forests.

Scientists are monitoring this constant cycle of erosion and deposition with drones equipped with LiDAR sensors. They also use telemeteric stations to track river levels and issue warnings to both residents and athletes. However, modeling this complex system is difficult due to the impact-absorbing mangrove ecosystems.

The shifting sediments also challenge archaeologists, exposing and submerging historical deposits. Researchers must excavate quickly before tides alter the terrain.

Balancing adventure tourism with environmental preservation requires strict regulations and the involvement of local communities. Ongoing research seeks to understand this ecological transition and Brazil’s coastal geomorphology.