Seabeds rise, 'lake' forms across parts of Mindanao following earthquake

The effects of the magnitude 7.8 earthquake in Mindanao continue to be observed across several areas.

According to Kuya Kim Atienza’s report on “24 Oras” on Tuesday, some coastal waters did not go back to normal following the quake, while what appeared to be lakes have also formed in other areas.

In a video from content creator Dacoyz Vlog, he showed the state of the coastal waters in his area of Barangay Kitayo, Jose Abad Santos in Davao Occidental, with the seabed now lifted and the corals exposed.

"Hindi pa rin bumabalik ang dagat. Naubusan na ng tubig. Ayun 'yung barangay namin, sobrang layo na," he said in the vlog.

The same happened in Barangay Pangyan in Glan, Sarangani. After the earthquake, the seabed lifted by two meters, and the seashore widened to almost 200 meters.

According to experts, this is not a sign of an upcoming tsunami but is the result of a coastal uplift, where the seashore is lifted because of the ground’s movement under the crust.

“’Yung parte ng mga dagat na naka-submerge noon, umangat siya sa lupa. Through time ‘to, mabagal na pag-angat tapos mag-sa-stabilize dahil sa tectonic uplift,” explained Philippine Institute of Volcanology and Seismology (PHIVOLCS) Senior Researcher Maria Isabel Abigania.

"Ito 'yung nangyari ngayon sa Sarangani, tectonic meaning co-seismic, kasabay ng napakalakas na lindol.

This change is also permanent, and the exposed corals, seagrass, and animals will eventually die.

“Paglipas ng panahon, magiging terrestrial ecosystem 'yung mag-te-takeover,” she added.

Meanwhile, the opposite happened in Barangay San Isidro, also in the town of Jose Abad Santos. Water had accumulated and turned into what appeared to be a lake. As water levels rose, vegetation became submerged, and some parts of the barangay are no longer passable, prompting residents to build rafts.

In a video by Norijoy Barlizo Elca, the lake-like formation was previously a river, but because of a landslide following the earthquake, the ground collapsed into the area.

“’Yung tubig, na-stuck doon sa mismong na-landslide. Hindi makalabas, nag-overflow doon sa area dahil sa five consecutive days na pag-ulan,” Elca said.

The local government unit is now exploring solutions to address the issue.

“We urgently requested to send heavy equipments, makakatulong sa amin. Na-cease po ‘yung operations nila kasi nga po frequent pa po ‘yung ground-shaking and there’s a big possibility na more landslide doon sa area,” said Julie Marie Muda Buen, municipal information officer of the Jose Abad Santos LGU.

Meanwhile, Kuya Kim reported that in Balut Island in Davao Occidental, some sinkholes in parts of coastal waters appeared after the earthquake.

Sinkholes form when the ground becomes too wet, especially if it is made from limestone. Per Kuya Kim, the suspected sinkholes in Balut Island may have formed due to the recent earthquake, which likely weakened the ground.

—Nika Roque/CDC, GMA News