IN THE KNOW: Benham Rise

Benham Rise, also known as Benham Plateau, is a 13-million hectare undersea region east of Luzon, off the provinces of Isabela and Aurora. It is bounded by the West Philippine Basin to the north and east.

It is enclosed by the coordinates 119°30’E to 132°00’E and 12°10’N to 20°30’N latitude.

The plateau is a massive formation of basalt, a common volcanic rock, and is described in a study as a thickened portion of the Philippine sea plate’s oceanic crust.

Another research notes the similarity of the shape of Benham Rise to the sharp bend of the Luzon coastline, which suggests the sea floor’s resistance to subduction (the process by which one plate on the earth’s crust is pushed downward beneath another plate because of collision) that may have affected the Philippine fault.

The formation lies within the continental shelf of the Philippines as defined by the 1982 UN Convention on the Law of the Sea (Unclos).

Under the Unclos, a coastal state’s exclusive economic zone extends 370 kilometers (200 nautical miles) from its continental shelf, while its extended continental shelf extends for another 278 km (150 nautical miles).

Benham Rise is not subject to any maritime boundary disputes and claims.

In April 2009, the Philippine government made a partial submission to the UN Commission on the Limits of the Continental Shelf in relation to the Benham Rise, noting that the Philippines may submit information on other areas of the Philippine continental shelf in the future. Lawrence de Guzman, Inquirer Research

Sources: Executive Summary of the Partial Submission of Data and Information on the outer Limits of the Continental Shelf of the Philippines; Department of Environment and Natural Resources; Geological Disasters in the Philippines; Inquirer Archives