Mariana Trench

Also known as: Marianas Trench — the plural styling common in older English usage · Marianas Trench system · Challenger Deep — strictly the trench's deepest basin, often used loosely for the trench itself · Mariana Hollow — the name given to the deep by the 1957 Soviet Vityaz survey

The serenade tradition, the Pinoy rap line, the ocean's deepest trench, and the National Press Club

Definition

The Mariana Trench is the deepest oceanic trench on Earth, a crescent-shaped scar in the western Pacific about 2,550 kilometers long and 69 kilometers wide, lying roughly 200 kilometers east of the Mariana Islands. Its lowest point, the Challenger Deep, reaches a maximum known depth of 10,935 ± 6 meters (per the 2021 survey literature) — the deepest seabed on the planet — beneath pressures of about 1,086 bar, roughly 1,071.8 times sea-level atmospheric pressure. The trench takes its name from the nearby Mariana Islands, named Las Marianas in honor of the Spanish Queen Mariana of Austria. (Wikipedia — Mariana Trench)

For the Philippines, the trench matters primarily as the eastern wall of the Philippine Sea — the marginal sea that bounds the archipelago’s Pacific side and carries the country’s name. The sea’s eastern rim is formed by the second island chain (the Bonin Islands, the Mariana Islands, and Palau), and its floor holds the Mariana and Philippine trenches, with the Mariana containing “the deepest point on the planet.” The trench itself lies outside Philippine jurisdiction: parts fall within the United States exclusive economic zone around the Marianas, protected since 2009 as a marine national monument, while the Challenger Deep lies within Micronesia’s EEZ. The Philippines’ own deep-sea frontier on that sea is the opposite, western margin — the Philippine Trench — and the underwater plateau the country successfully claimed before the United Nations, the Benham or Philippine Rise. (Wikipedia — Mariana Trench, Wikipedia — Philippine Sea)

Identities

Source Type	Identity
Wikipedia	Mariana Trench
Wikidata	Mariana Trench (Q510)
DBpedia	Mariana_Trench
ProductOntology	N/A
Wiktionary	Mariana Trench
Library of Congress Subject Headings (LCSH)	Mariana Trench (sh2010012231)
MeSH	N/A
NCBI Taxonomy	N/A
AGROVOC	N/A
Google Scholar	Mariana Trench Challenger Deep subduction hadal zone exploration
ConceptNet	N/A
OpenCyc	N/A

Also Known As

Marianas Trench — the plural styling common in older English usage
Marianas Trench system
Challenger Deep — strictly the trench’s deepest basin, often used loosely for the trench itself
Mariana Hollow — the name given to the deep by the 1957 Soviet Vityaz survey

Examples and Analogies

A thousand atmospheres: the pressure at the bottom — about 1,071.8 times atmospheric at sea level — functions as the engineering definition of the place; every vehicle that visits must be built like a moving pressure vessel. (Wikipedia — Mariana Trench)
The Philippine Sea’s eastern stair: the trench works like the steep edge of a giant basin — the Pacific plate diving westward beneath the Mariana plate — with the Philippine Sea as the yard behind the wall; the Philippines sits on that yard’s western fence, which is why the sea, not the trench, is the Philippine geography. (Wikipedia — Mariana Trench, Wikipedia — Philippine Sea)
Old crust swallowed young: the Pacific crust entering the subduction zone is up to 170 million years old — among the oldest oceanic crust on Earth — so the trench is where the planet’s oldest seafloor goes under. (Wikipedia — Mariana Trench)
The Philippine Rise as the mirror case: where the Mariana Trench is a depth claimed by no Philippine flag, the Benham Rise is a height the Philippines proved its own — a 13-million-hectare plateau on the same sea, confirmed to the country by the UN Commission on the Limits of the Continental Shelf in April 2012 and renamed “Philippine Rise” by Executive Order No. 25 in 2017. (Wikipedia — Benham Rise, LawPhil — Executive Order No. 25 (2017))

Usage Scenarios

1. Deep-Ocean Science

The trench is the reference site for hadal biology and geology: giant xenophyophores recorded at 10.6 kilometers, the Mariana snailfish filmed at 8,178 meters, and 2025 studies reporting more than 7,000 microbial species, 89 percent new to science. (Wikipedia — Mariana Trench)

2. Deep-Submergence Engineering

Crewed and uncrewed vehicle programs test at the trench as the planet’s extreme benchmark — from the 1960 bathyscaphe Trieste to the 2012 Deepsea Challenger and the Limiting Factor submersible; as of 2022, 22 crewed and seven uncrewed descents had been achieved. (Wikipedia — Mariana Trench)

3. Marine Policy and Jurisdiction

The trench is a case study in ocean governance: the United States designated portions within its EEZ as the Mariana Trench Marine National Monument in 2009, while the Challenger Deep itself, lying within Micronesia’s EEZ, is excluded from the monument. (Wikipedia — Mariana Trench)

4. Philippine Maritime Education and Mapping

For Philippine audiences the trench anchors lessons on the Philippine Sea system and on the country’s own UNCLOS record — the 2009 extended continental shelf submission and 2012 Commission approval for the Benham Rise, and the 2017 renaming to Philippine Rise that made nomenclature itself national policy. (Wikipedia — Benham Rise, LawPhil — Executive Order No. 25 (2017))

Strategies

Standardize the depth record: successive surveys — 8,184 meters (1875, weighted line), about 10,900 meters (1951, echo sounding), 11,034 meters (1957), 10,924 meters (1984), 10,911 meters (1995, ROV), and 10,935 ± 6 meters (2021) — show the strategy of refining the figure with better acoustics rather than declaring it once. (Wikipedia — Mariana Trench)
Protect by jurisdiction: the 2009 monument strategy — protecting the trench sections within the US EEZ — trades comprehensive coverage for enforceable law, the standard UNCLOS-era approach to hadal conservation. (Wikipedia — Mariana Trench)
Name to govern: the Philippine experience shows nomenclature as strategy — renaming Benham Rise to Philippine Rise in 2017, on the strength of the UN-confirmed shelf claim, to fix the feature to the national map. (LawPhil — Executive Order No. 25 (2017))
Cooperate across flags: with the trench spanning US and Micronesian zones and visited by Russian, Chinese, Japanese, and American vehicles, research access runs on international logistics — the operating pattern every modern expedition follows. (Wikipedia — Mariana Trench)

Security and Safety Measures

Pressure-hull engineering: every crewed visit survives on certified titanium pressure spheres and redundant systems — the safety envelope that has carried divers from Don Walsh and Jacques Piccard (1960) through James Cameron (2012) to Victor Vescovo’s repeat dives (2019–2020). (Wikipedia — Mariana Trench)
Pollution monitoring at the deepest point: the trench doubles as a global-contamination gauge — PCBs in crustaceans, microplastics in 100 percent of sampled amphipods, and a plastic bag and candy wrappers observed in 2019 — the evidence base for pollution-control measures far from any shore. (Wikipedia — Mariana Trench)
Maritime-domain awareness on the Philippine margin: the Philippine-side lesson of the record is vigilance over the country’s own seabed — the 2017–2018 episodes of unpermitted foreign surveying over the Philippine Rise that prompted objections and stricter clearance practice. (Wikipedia — Benham Rise)
Verify depth and jurisdiction claims: because figures and boundaries differ across sources, researchers should anchor both to the survey literature and the applicable EEZ determinations rather than to popular retellings. (Wikipedia — Mariana Trench)

Historical Context

The trench is the southern end of the Izu–Bonin–Mariana subduction system, where the Pacific plate bends beneath the smaller Mariana plate; the name is colonial Spanish, honoring Queen Mariana of Austria through the Mariana Islands. The depth record begins with the 1875 HMS Challenger sounding of 4,475 fathoms (8,184 meters), corrected upward by the USS Nero (1899) and HMS Challenger II (1951, about 10,900 meters), with the Soviet Vityaz reporting 11,034 meters in 1957 and modern multibeam surveys converging on 10,935 ± 6 meters by 2021. The crewed era opened on January 23, 1960, when Don Walsh and Jacques Piccard reached the bottom in the bathyscaphe Trieste; James Cameron descended solo in the Deepsea Challenger in 2012 (10,908 meters); Victor Vescovo’s Limiting Factor dove in 2019 and 2020 to about 10,935 meters; and Chinese and Russian vehicles followed in 2020 — 22 crewed descents in all by 2022. (Wikipedia — Mariana Trench)

The Philippine dimension runs through the sea, not the trench. The sea’s basin — bounded by Taiwan and the Ryukyus, the Marianas and Palau — holds the Mariana Trench on its eastern side and, facing the archipelago on the west, the Philippine Trench. Philippine jurisdiction in that sea was fixed not in the Mariana Trench but on the plateau east of Isabela: the Philippines lodged its partial submission for the Benham Rise continental shelf with the UN Commission on April 8, 2009, won approval in April 2012 — the first Philippine claim approved by an international body since the colonial era — and renamed the feature Philippine Rise by Executive Order No. 25 (May 16, 2017), which directs that maps, charts, and official documents carry the Filipino name. The trench’s own governance fell to the United States, whose 2009 marine national monument protects its EEZ portions, with the Challenger Deep outside the monument in Micronesian waters. (Wikipedia — Philippine Sea, Wikipedia — Benham Rise, LawPhil — Executive Order No. 25 (2017))

Challenges and Controversies

Jurisdiction Over the Deepest Point

The deepest seabed on Earth lies in Micronesia’s EEZ and outside the 2009 US monument — a boundary configuration that leaves the planet’s most iconic deep site under ordinary national jurisdiction rather than any special protected status, the standing puzzle of hadal conservation. (Wikipedia — Mariana Trench)

Whose Numbers Are Right

A century and a half of surveys has produced figures from 8,184 to 11,034 meters before the modern convergence near 10,935 meters; older sources (and their echoes in textbooks) still carry superseded depths, so the record must be cited by survey, not by round number. (Wikipedia — Mariana Trench)

Pollution at the Bottom

The discovery that every sampled amphipod contained microplastics, and that litter has been sighted at the deepest point, made the trench the emblem of global plastic contamination — a finding repeatedly cited in debates over marine-pollution regulation. (Wikipedia — Mariana Trench)

Naming and Sovereignty in the Philippine Sea

The sea around the Philippines carries layered names — a Spanish queen’s name on the trench, a colonial-era American name (Benham) on the Philippine plateau until 2017, Chinese-proposed names on five Philippine Rise features in 2018 over Philippine objection — so that mapping itself is contested terrain; the Philippine response, Executive Order No. 25, treats nomenclature as an attribute of sovereignty over its confirmed shelf. (Wikipedia — Mariana Trench, Wikipedia — Benham Rise, LawPhil — Executive Order No. 25 (2017))