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Seikan Tunnel

Undersea railway tunnel in Japan

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General referenceInterpretive dossier study · Crown Archives visual atlas
Record originEnglish Wikipedia
Text licenseCC BY-SA 4.0
Source revisionSep 13, 2026
Entity authoritySource title only
Source-derived summary

The Seikan Tunnel is a 53.85-kilometre (33.5-mile) dual-gauge railway tunnel in Japan, with a 23.3-kilometre (14.5-mile) segment running beneath the seabed of the Tsugaru Strait, which separates Aomori Prefecture on Honshu, Japan's main island, from the northern island of Hokkaido. The tunnel's track level lies approximately 100 metres (330 ft) below the seabed and 240 metres (790 ft) below sea level. Following several decades of planning and construction, the tunnel opened on 13 March 1988.

Editorial summary

The public source identifies “Seikan Tunnel” as undersea railway tunnel in Japan. This brief keeps that definition visible, then builds a research path around Seikan, Tunnel and Undersea.

Editorial reviewA practical starting point whose main value is the path it opens into stronger specialist and primary sources. The current lead gives the account dated anchors—1988—that can be checked directly. The selected authority fields contribute no independent date. Its value is orientation rather than verdict, with Seikan, Tunnel and Undersea providing the first useful test.
Editorial analysis

Why this record matters

A short description can identify a subject without explaining its stakes. For “Seikan Tunnel”, the useful work is to connect “undersea railway tunnel in Japan” to the records capable of establishing context and consequence.

Evidence profile

The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated Sep 13, 2026. The first chronological checks are 1988.

Critical limits

Overview language is designed for orientation and should not be treated as a substitute for the evidence cited beneath it. 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

Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.

Best used for
  • Subject orientation
  • Search vocabulary
  • Locating named sources
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The closest primary source, responsible institution and strongest cited specialist reference.

Three-step research path

  1. Establish the record: confirm the title “Seikan Tunnel”, its source revision and the description used here.
  2. Expand the search: follow Seikan Tunnel primary sources, Seikan Tunnel archive and Seikan research across catalogues and specialist indexes.
  3. Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.

Questions for further research

  1. Which source most directly establishes the central claim about “Seikan Tunnel”?
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Source & attribution

This entry incorporates text from “Seikan Tunnel” 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.