Philippine Sea
sea in the Pacific Ocean

The Philippine Sea is a marginal sea of the Western Pacific Ocean east of the Philippine Archipelago and the largest sea in the world, occupying an estimated surface area of 5 million square kilometers (2×10^6 sq mi). The Philippine Sea Plate forms the floor of the sea. Its western border is the first island chain to the west, comprising the Ryukyu Islands in the northwest and Taiwan in the west. Its southwestern border comprises the Philippine islands of Luzon, Catanduanes, Samar, Leyte, and Mindanao. Its northern border comprises the Japanese islands of Honshu, Shikoku and Kyūshū. Its eastern border is the second island chain to the east, comprising the Bonin Islands and Iwo Jima in the northeast, the Mariana Islands (including Guam, Saipan, and Tinian) in the due east, and Halmahera, Palau, Yap and Ulithi (of the Caroline Islands) in the southeast. Its southern border is Indonesia's Morotai Island.
The sea has a complex and diverse undersea relief. The floor is formed into a structural basin by a series of geologic faults and fracture zones. Island arcs, which are actually extended ridges protruding above the ocean surface due to plate tectonic activity in the area, enclose the Philippine Sea to the north, east and south.
This brief starts where responsible research should: with the source description of “Philippine Sea” as sea in the Pacific Ocean. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the places & architecture register because the source frames it as sea in the Pacific Ocean. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Maps, plans, fabric surveys and administrative records can establish how the site’s name, extent and function changed over time. The source revision retrieved here is dated Aug 29, 2026. The linked authority identifier is Q159183. VIAF identifies the subject as 315526857. The Library of Congress control number is sh85100765. Authority coordinates are 18.000, 134.000. 1 of 3 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank.
A single description cannot reconcile every naming convention, rebuilding phase or administrative transfer associated with a place. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Treat names, boundaries and functions as historically changeable. Maps, plans, inventories and administrative records can clarify what the place meant at different dates.
- Historic place names
- Jurisdictional context
- Routes into maps and plans
Contemporary maps, plans, listed-building records, estate papers and the responsible local or national archive.
Three-step research path
- Establish the record: confirm the title “Philippine Sea”, its source revision and the description used here.
- Expand the search: follow Philippine Sea primary sources, Philippine Sea archive and Philippine research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Philippine Sea”?
- Which earlier names or jurisdictions may reveal additional records?
- Which authority defined the place, boundary or structure at the relevant date?
Search terms from this dossier
This entry incorporates text from “Philippine Sea” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.