is a

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

in the

Kiso Mountains are a mountain range in Nagano and Gifu prefectures in Japan. They are also called the and they combine with the Hida Mountains ("Northern Alps") and the Akaishi Mountains ("Southern Alps") to form a group collectively known as the Japanese ...

, in the central region of

Nagano Prefecture is a landlocked prefecture of Japan located in the Chūbu region of Honshū. Nagano Prefecture has a population of 2,052,493 () and has a geographic area of . Nagano Prefecture borders Niigata Prefecture to the north, Gunma Prefecture to the ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

Geography

The lake is the source of the

Tenryū River The is a river in central Honshū, Japan. With a length of , it is Japan's ninth longest river. Its source is Lake Suwa in the Kiso Mountains near Okaya in Nagano Prefecture. It then flows through Aichi Prefecture and western Shizuoka Prefect ...

. It ranks 24th in lake water surface area in Japan. The cities of Suwa and Okaya and the town of

Shimosuwa is a town located in Nagano Prefecture, Japan. , the town had an estimated population of 20,055 in 8864 households, and a population density of 300 persons per km². The total area of the town is . Geography Shimosuwa is located in central Na ...

are located on the shores of Lake Suwa.

Omiwatari

Lake Suwa is the site of a natural phenomenon known as the , large cracks that form in the winter across the surface of the frozen lake. A vertical temperature gradient results in ice pressure ridges forming in the surface ice, reaching heights of or more. 180205 Lake Suwa omiwatari 01

Local

Shinto Shinto () is a religion from Japan. Classified as an East Asian religion by scholars of religion, its practitioners often regard it as Japan's indigenous religion and as a nature religion. Scholars sometimes call its practitioners ''Shintois ...

tradition holds that the ridges are formed by the gods crossing the lake when traveling between the various buildings of the

Suwa Grand Shrine , historically also known as Suwa Shrine (諏訪神社 ''Suwa-jinja'') or , is a group of Shinto shrines in Nagano Prefecture, Japan. The shrine complex is the ''ichinomiya'' of former Shinano Province and is considered to be one of the oldest sh ...

. Folklore says it is the guardian god of Suwa, Takeminakata-no-kami, leaving his sanctuary to meet with his wife, the goddess , joining the opposite bank by walking on frozen water. The record of this crossing is the oldest-known human-observed climate record. This record has been used by scientists to study the impact of sunspots, human development and anthropogenic CO₂ emissions on lake ice formation. The lake has a natural

hot spring A hot spring, hydrothermal spring, or geothermal spring is a spring produced by the emergence of geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow bodies of magma (molten rock) or by circ ...

under its surface. Recreational development in the 1950s resulted in increased output from this underwater geyser. Since 1945, complete ice cover is considered to be achieved when the entire surface is frozen except for the opening in the ice for the geyser. As a shallow lake, Lake Suwa is highly sensitive to climatic variation. Recent studies have shown that Suwa's ice-free years correlate to increasing atmospheric CO₂ levels. Research on ice breakup at Suwa and at the mouth of the

Torne River The Torne, also known as the Tornio ( fi, Tornionjoki, sv, Torne älv, , se, Duortneseatnu, fit, Tornionväylä), is a river in northern Sweden and Finland. For approximately half of its length, it defines the border between these two countr ...

Finland Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of B ...

suggest that climate change is driving the changes in seasonal ice cover. As a result, it is expected that Lake Suwa will remain ice-free for almost the entirety of the 21st century's winters.

Cultural history

Lake Suwa hosts two major shrines, the Tenaga Jinja and the Suwa Jinja. Major festivals include the

Onbashira The are four wooden posts or pillars that stand on the four corners of local shrines in the Lake Suwa area of Nagano Prefecture (historical Shinano Province), Japan. The largest and most famous set of are those that stand on the four shrines ...

and

Setsubun is the day before the beginning of spring in the old calendar in Japan. The name literally means 'seasonal division', referring to the day just before the first day of spring in the traditional calendar, known as ; though previously referri ...

Hokusai , known simply as Hokusai, was a Japanese ukiyo-e artist of the Edo period, active as a painter and printmaker. He is best known for the woodblock printing in Japan, woodblock print series ''Thirty-Six Views of Mount Fuji'', which includes the ...

included Lake Suwa in his famous Thirty-six Views of Mount Fuji (Fugaku sanjūrokkei) series of

woodblock prints Woodblock printing or block printing is a technique for printing text, images or patterns used widely throughout East Asia and originating in China in antiquity as a method of printing on textiles and later paper. Each page or image is crea ...

Epson Seiko Epson Corporation, or simply known as Epson, is a Japanese multinational electronics company and one of the world's largest manufacturers of computer printers and information- and imaging-related equipment. Headquartered in Suwa, Nagano ...

, a global technology company, was founded and is headquartered in Suwa.

In popular culture

In the movie ''

Kagemusha is a 1980 jidaigeki film directed by Akira Kurosawa. It is set in the Sengoku period of Japanese history and tells the story of a lower-class criminal who is taught to impersonate the dying ''daimyō'' Takeda Shingen to dissuade opposing lords fr ...

'' by

Akira Kurosawa was a Japanese filmmaker and painter who directed thirty films in a career spanning over five decades. He is widely regarded as one of the most important and influential filmmakers in the history of cinema. Kurosawa displayed a bold, dyna ...

, the corpse of Lord Shingen is dropped into the lake. This film dramatizes the events leading up to the 1575

Battle of Nagashino The took place in 1575 near Nagashino Castle on the plain of Shitaragahara in the Mikawa Province of Japan. Takeda Katsuyori attacked the castle when Okudaira Sadamasa rejoined the Tokugawa, and when his original plot with Oga Yashiro for taki ...

. Sayo Masuda, author of ''

Autobiography of a Geisha is a book by . It was first published in Japan in 1957, and the English translation by G. G. Rowley was published in 2003. Masuda wrote her autobiography between the years of 1956 and 1957 in response to a magazine ad for a non-fiction women's w ...

'', was sold by her family to an okiya (geisha house) in Suwa at the age of 12. She tries to drown herself in the lake, but hesitates because she believes a dragon (possibly related to the omiwatari) inhabits it. *In the anime ''

Rurouni Kenshin is a Japanese manga series written and illustrated by Nobuhiro Watsuki. The story begins during the 11th year of the Meiji period in Japan (1878) and follows a former assassin from the Bakumatsu, known as Hitokiri Battosai. After his wor ...

'', legend holds of an "Elixir of Immortality" that can be found somewhere in or around Lake Suwa. The main characters search for the elixir in the final season of the series and are followed by a band of evil German knights, seeking it for world domination. *The anime ''

Blood-C ''Blood-C'' (stylized as ''BLOOD-C'') is a 2011 Japanese anime television series co-created by studio Production I.G and manga artist group CLAMP. It is the second anime series in the ''Blood'' franchise following the 2005–2006 seri ...

'' takes place in a rural town located on the shore of the lake. *Suwako Moriya from the '' Touhou Project'' is named after the lake. *This lake is also popular because from the movie of ''

Your Name is a 2016 Japanese animated romantic fantasy film produced by CoMix Wave Films. It depicts a high school boy in Tokyo and a high school girl in the Japanese countryside who suddenly and inexplicably begin to swap bodies. The film was commis ...

'' as it gained its tourist visitors. The Itomori town where Mitsuha (Main Female Protagonist) lived was modeled after the Lake Suwa in Gifu.

References

{{Authority control Suwa Landforms of Nagano Prefecture Kiso Mountains

Geography

Omiwatari

Cultural history

In popular culture

See also

References