After Pinay marine geophysicist discovers world's largest caldera: What is a caldera and how does it form?

The Apolaki Caldera, known to be the world's largest caldera to date, was discovered in Benham Rise by a Pinay marine geophysicist Jenny Anne Barretto and her team.

READ: Pinay scientist discovers 'largest caldera' Apolaki in Benham Rise

What exactly is a caldera?

The US Geological Survey (USGS) describes a caldera as a large basin-shaped volcanic depression with a diameter larger than volcanic vents.

Calderas can measure from 2 to 50 km across, according to the science agency.

What makes the recently-discovered Apolaki extraordinary is it's measured about 150 km in diameter — 90 km bigger than the Yellowstone Caldera.

"[Calderas] are commonly formed when magma erupts from a shallow underground magma reservoir. The removal of large volumes of magma may result in loss of structural support for the overlying rock, thereby leading to collapse of the ground and formation of this of large depression," the USGS said in its website.

In Barretto and her team's abstract detailing the morphology and structure of the Benham Rise, the Apolaki caldera may have been formed because of the island's 'multi-phase volcanic history of quiet and explosive eruptions' in the past.

The name Apolaki, which means giant lord, was inspired by the god of sun and war in Philippine mythology. — LA, GMA News