Filipina geophysicist discovers ‘world’s largest caldera’ in Benham Rise

A Filipina marine geophysicist discovered what could be the largest caldera in Philippine Rise or Benham Rise.

The New Zealand-based scientist, Jenny Anne Barretto, together with Ray Wood and John Milson, discovered the caldera. The scientists named the discovery in Benham Rise as “Apolaki Caldera,” after a Filipino mythical sun and god.

“For comparison, Earth’s largest calderas, like the Yellowstone, is only about 60 kilometers (km). The size is comparable to shield calderas on Mars (Olympus Mons; 80 km x 65 km) and Venus (Sacajawea; 150 X 105 km),” the University of the Philippines Marine Institute said Monday in a Facebook post.

The study of the Filipina geophysicist was entitled “Benham Rise unveiled: Morphology and structure of an Eocene large igneous province in the West Philippine Basin.”

A caldera is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber/reservoir in a volcanic eruption.  The ground surface then collapses downward into the emptied or partially emptied magma chamber, leaving a massive depression at the surface (from one to dozens of kilometers in diameter). Although sometimes described as a crater, the feature is a type of sinkhole, as it is formed through subsidence and collapse rather than an explosion or impact. Only seven caldera-forming collapses are known to have occurred since 1900, most recently at Bárðarbunga volcano, Iceland in 2014.

Last year, President Rodrigo Duterte downplayed China’s controversial decision to name five undersea features in the Philippine Rise — a maritime region to the northeast of the Philippines formerly known as Benham Rise.