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Sea of Japan

Sea of Japan is a earth science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Sea of Japan rather than just read about it. In short: The Sea of Japan (see § Names for other names) is the marginal sea between the Japanese archipelago, Sakhalin, the Korean Peninsula, and the mainland of the Russian Far East. The Japanese archipelago separates the sea from the Pacific Ocean.

Sea of Japan — main illustration
Sea of Japan — illustration

Key takeaways

  • Sea of Japan belongs to earth science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Sea of Japan to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Sea of Japan from memory before moving on to harder problems.

Reference excerpt

The Sea of Japan (see § Names for other names) is the marginal sea between the Japanese archipelago, Sakhalin, the Korean Peninsula, and the mainland of the Russian Far East. The Japanese archipelago separates the sea from the Pacific Ocean. Like the Mediterranean Sea, it has almost no tides due to its nearly complete enclosure from the Pacific Ocean. This isolation also affects faunal diversity and salinity, both of which are lower than in the open ocean. The sea has no large islands, bays or capes. Its water balance is mostly determined by the inflow and outflow through the straits connecting it to the neighboring seas and the Pacific Ocean. Few rivers discharge into the sea and their total contribution to the water exchange is within 1%. The seawater has an elevated concentration of dissolved oxygen that results in high biological productivity. Therefore, fishing is the dominant economic activity in the region. The intensity of shipments across the sea has been moderate owing to political issues, but it is steadily increasing as a result of the growth of East Asian economies.

Names Sea of Japan is the dominant term used in English for the sea. The sea is called Nihon kai (日本海, transl. Japan Sea) in Japan, Rìběn hǎi (日本海, transl. Japan Sea) or originally Jīng hǎi (鲸海, transl. Whale Sea) in China, Yaponskoye more (Японское море, transl. Japanese Sea) in Russia, Chosŏn Tonghae (조선동해, transl. Korean East Sea) in North Korea, and Donghae (동해, transl. East Sea) in South Korea.

Naming dispute

The naming of the sea is the subject of an ongoing dispute between Japan, North Korea, and South Korea. Japan uses the name Sea of Japan and asserts that it has been the internationally accepted term since the early 19th century. In contrast, South Korea contends that the East Sea was historically used before Japanese colonial rule, and officially requests that it be used alongside Sea of Japan. North Korea advocates for the name East Sea of Korea. Limits of Oceans and Seas (S-23), published by the International Hydrographic Organization (IHO), had been using the name Japan Sea since it was first published in 1928. It has not been updated since 1953 and is not able to effectively serve as an international standard in today's digital environment. In 2020, the IHO decided to develop a new digital standard, S-130, to meet modern Geographic Information System (GIS) requirements and replace the geographic names in S-23 with unique identifiers for each maritime area in S-130. The IHO Secretary-General stated that S-23, the previous version of the nautical chart made in 1953 will be kept publicly available simply to demonstrate the evolutionary process from the analogue to the digital era.

History For centuries, the sea had protected Japan from land invasions, particularly by the Mongols. It had long been navigated by Asian and, from the 18th century, by European ships. Russian expeditions of 1733–1743 mapped Sakhalin and the Japanese islands. In the 1780s, the Frenchman Jean-François de Galaup, comte de Lapérouse, traveled northward across the sea through the strait later named after him. In 1796, a British naval officer, William Robert Broughton, explored the Strait of Tartary, the eastern coast of the Russian Far East and the Korean Peninsula. In 1803–1806, the Russian navigator Adam Johann von Krusenstern while sailing across the globe in the ship Nadezhda also explored, in passing, the Sea of Japan and the eastern shores of Japanese islands. In 1849, another Russian explorer Gennady Nevelskoy discovered the strait between the continent and Sakhalin and mapped the northern part of the Strait of Tartary. Russian expeditions were made in 1853–1854 and 1886–1889 to measure the surface temperatures and record the tides. They also documented the cyclonal character of the sea currents. Other notable expeditions of the 19th century include the American North Pacific Exploring and Surveying Expedition (1853–1856) and British Challenger expedition (1872–1876). The aquatic life was described by V. K. Brazhnikov in 1899–1902 and P. Yu. Schmidt in 1903–1904. The Japanese scientific studies of the sea began only in 1915 and became systematic since the 1920s. American, Canadian and French whaleships cruised for whales in the sea between 1847 and 1892. Most entered the sea via Korea Strait and left via La Pérouse Strait, but some entered and exited via Tsugaru Strait. They primarily targeted right whales, but began catching humpbacks as right whale catches declined. They also made attempts to catch blue and fin whales, but these species invariably sank after being killed. Right whales were caught from March to September, with peak catches in May and June. During the peak years of 1848 and 1849 a total of over 170 vessels (over 60 in 1848, and over 110 in 1849) cruised in the Sea of Japan, with significantly lesser numbers in following years.

Geography and geology

… excerpt ends here. Continue reading the full article.

Illustrations

Sea of Japan illustration
Sea of Japan: Relief of the Sea of Japan and nearby areas
Relief of the Sea of Japan and nearby areas
Sea of Japan: Map showing Japanese archipelago, Sea of Japan and surrounding part of continental East Asia in Early Miocene (23–18 Ma)
Map showing Japanese archipelago, Sea of Japan and surrounding part of continental East Asia in Early Miocene (23–18 Ma)
Sea of Japan: Map showing Japanese archipelago, Sea of Japan and surrounding part of continental East Asia in Middle Pliocene to Late Pliocene (3.5–2 Ma)
Map showing Japanese archipelago, Sea of Japan and surrounding part of continental East Asia in Middle Pliocene to Late Pliocene (3.5–2 Ma)
Sea of Japan illustration

Worked examples

Example 1 — a first encounter with Sea of Japan

Start with the simplest possible case. Write down what Sea of Japan claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In earth science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Sea of Japan before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Sea of Japan ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Sea of Japan

In research
Sea of Japan appears in earth science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Sea of Japan in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Sea of Japan is common in secondary-school and first-year university syllabi. It links to neighbouring topics Bodies of water of Khabarovsk Krai, Bodies of water of Primorsky Krai, Bodies of water of Sakhalin Oblast, so understanding it makes those chapters shorter.
In everyday life
Look for Sea of Japan outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Sea of Japan in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Sea of Japan means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Sea of Japan out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Sea of Japan in simple terms?

The Sea of Japan (see § Names for other names) is the marginal sea between the Japanese archipelago, Sakhalin, the Korean Peninsula, and the mainland of the Russian Far East. The Japanese archipelago separates the sea from the Pacific Ocean.

Why does Sea of Japan matter?

Because it connects several earth science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Sea of Japan?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Sea of Japan.

Tags

  • Bodies of water of Khabarovsk Krai
  • Bodies of water of Primorsky Krai
  • Bodies of water of Sakhalin Oblast
  • Geography of Japan
  • Geography of Korea
  • Geography of Northeast Asia
  • Geography of the Russian Far East
  • Marginal seas of the Pacific Ocean
  • Marine ecoregions
  • Miocene Asia
  • Pacific Coast of Russia
  • Sea of Japan

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