Philippine Trench in the context of "Philippine Sea"

Limiting Factor, known as Bakunawa since its sale in 2022, and designated Triton 36000/2 by its manufacturer, is a crewed deep-submergence vehicle (DSV) manufactured by Triton Submarines, built for and originally owned and operated (2018–2022) by explorer Victor Vescovo's ocean research firm, Caladan Oceanic, and currently owned and operated by Gabe Newell's Inkfish ocean-exploration research organization. It currently holds the records for the deepest crewed dives in all five oceans. Limiting Factor was commissioned by Victor Vescovo for $37 million and operated by his marine research organization, Caladan Oceanic, between 2018 and 2022. It is commercially certified by DNV for dives to full ocean depth, and is operated by a pilot, with facilities for an observer.

The vessel was used in the Five Deeps Expedition, becoming the first crewed submersible to reach the deepest point in all five oceans. Over 21 people have visited Challenger Deep, the deepest area on Earth, in the DSV. Limiting Factor was used to identify the wrecks of the destroyers USS Johnston at a depth of 6,469 m (21,224 ft), and USS Samuel B. Roberts at 6,865 m (22,523 ft), in the Philippine Trench, the deepest dives on wrecks. It has also been used for dives to the French submarine Minerve (S647) at about 2,350 m (7,710 ft) in the Mediterranean sea, and RMS Titanic at about 3,800 m (12,500 ft) in the Atlantic.

The Philippine Sea plate or the Philippine plate is a tectonic plate comprising oceanic lithosphere that lies beneath the Philippine Sea, to the east of the Philippines. Most segments of the Philippines, including northern Luzon, are part of the Philippine Mobile Belt, which is geologically and tectonically separate from the Philippine Sea plate.

The plate is bordered mostly by convergent boundaries: To the north, the Philippine Sea plate meets the Okhotsk microplate at the Nankai Trough. The Philippine Sea plate, the Amurian plate, and the Okhotsk plate meet near Mount Fuji in Japan. The thickened crust of the Izu–Bonin–Mariana arc colliding with Japan constitutes the Izu Collision Zone. The east of the plate includes the Izu–Ogasawara (Bonin) and the Mariana Islands, forming the Izu–Bonin–Mariana Arc system. There is also a divergent boundary between the Philippine Sea plate and the small Mariana plate which carries the Mariana Islands. To the east, the Pacific plate subducts beneath the Philippine Sea plate at the Izu–Ogasawara Trench. To the south, the Philippine Sea plate is bounded by the Caroline plate and Bird's Head plate. To the west, the Philippine Sea plate subducts under the Philippine Mobile Belt at the Philippine Trench and the East Luzon Trench. (The adjacent rendition of Prof. Peter Bird's map is inaccurate in this respect.) To the northwest, the Philippine Sea plate meets Taiwan and the Nansei islands on the Okinawa plate, and southern Japan on the Amurian plate.It also meets the Yangtze plate due northwest.

In the geology of the Philippines, the Philippine Mobile Belt is a complex portion of the tectonic boundary between the Eurasian plate and the Philippine Sea plate, comprising most of the Philippine archipelago. It includes two subduction zones, the Manila Trench to the west and the Philippine Trench to the east, as well as the Philippine fault system. Within the Belt, a number of crustal blocks or microplates which have been shorn off the adjoining major plates are undergoing massive deformation.

Most segments of the Philippines, including northern Luzon, are part of the Philippine Mobile Belt, which is bounded by the Philippine Sea plate to the east, the Molucca Sea Collision Zone to the south, Sunda plate to the southwest, and the South China Sea Basin to the west and north-west. To the north it ends in eastern Taiwan, the zone of active collision between the North Luzon Trough portion of the Luzon Volcanic Arc and South China. The Philippine Mobile Belt has also been called the Philippine Microplate and the Taiwan–Luzon–Mindoro Belt.

The subduction tectonics of the Philippines is the control of geology over the Philippine archipelago. The Philippine region is seismically active and has been progressively constructed by plates converging towards each other in multiple directions. The region is also known as the Philippine Mobile Belt due to its complex tectonic setting.

The region is bounded by subduction zones, where surrounding oceanic plates to the east and west slide towards the centre of the Philippine archipelago. Subduction results in deep oceanic trenches, such as the Philippine Trench and Manila Trench, which bound the eastern and western sides of the Philippine archipelago, respectively. The Philippine archipelago is also cut along its length by a left-lateral strike-slip fault known as the Philippine Fault.