Geologists from the University of the Philippines Diliman have discovered evidence of extreme waves on a large rock in Pasquin, Ilocos Norte. This could help coastal regions prepare for similar events in the future.

Adrian Tuvarado of the UP National Institute of Geological Sciences said that by analyzing the rocks, his team can reconstruct past extreme wave events, estimate their intensity and determine when they occurred.

These phenomena include tsunamis and severe storms.

The findings could help local governments and communities become more prepared for hazards through better evacuation planning, building codes and resilient coastal infrastructure.

Tuvarado explained that these rocks are primarily made of fossilized corals called coastal carbonate rocks.

He said his team measured the size, weight and location of the rocks and used specialized dating techniques to determine the age of the coral components.

“These dates tell us when the coral boulders were transported from seawater to the shore,” Tubarad says.

He added that the size and weight of the rocks, such as the 31-ton boulder cut down in the lab, reveals how strong the waves were.

The study also revealed that wave heights could reach around 4 meters in the town of Pasquin.

“Our spatial analysis showed that certain areas were more susceptible to rock accumulation and damage. For example, areas with embankments, coastal depressions, and steep slopes near the coast received stronger wave energy. This helps us identify which areas face the greatest risk,” Tuvarado said.

“Climate change is likely to increase the intensity of tropical cyclones, making it even more important to understand the baseline of past polar wave events to predict future risks and help coastal communities adapt accordingly,” he added.

The title of the study is “Extreme wave events inferred from large aerial carbonate rocks on the rocky coast of Pasquin, Ilocos Norte, Philippines.”

The paper was published in Marine Geology, a journal focused on marine geological processes. —Mariel Celine Serquiña/RF, GMA Integrated News