Senjōjiki Cirque (千畳敷カール) is a

cirque A (; from the Latin word ') is an amphitheatre-like valley formed by glacial erosion. Alternative names for this landform are corrie (from Scottish Gaelic , meaning a pot or cauldron) and (; ). A cirque may also be a similarly shaped landform ...

(

glacial landform Glacial landforms are landforms created by the action of glaciers. Most of today's glacial landforms were created by the movement of large ice sheets during the Quaternary glaciations. Some areas, like Fennoscandia and the southern Andes, have ...

) that lies just under

Mount Hōken Mount Hōken () is one of major peaks in Kiso Mountains or Central Alps, Nagano Prefecture, Japan. It is 2,931 m (9,616 ft) high, and its shape is sharp pyramidal peak. Geography Mount Hōken is located on the main ridgeline of Kiso mountains, abo ...

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 Al ...

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 ...

. It is called "Senjōjiki Kaaru" in Japanese. "Senjōjiki" means the wideness of 1000

tatami A is a type of mat used as a flooring material in traditional Japanese-style rooms. Tatamis are made in standard sizes, twice as long as wide, about 0.9 m by 1.8 m depending on the region. In martial arts, tatami are the floor used for traini ...

mats. Access to the cirque is easy via the "

Komagatake Ropeway is an aerial lift line in the Kiso Mountains range, Nagano Prefecture, Japan. Description The line, opened in 1967, climbs up to Senjōjiki Cirque 2600m above sea level, and it is easiest route to Mount Kisokoma and Mount Hōken. Summit station ...

" aerial lift which runs all year from the bottom of cirque. It is useful not only for mountaineers but also by sightseers. In summer, it is filled by numerous alpine flowers, and in winter it change to snowy mountain landscape. Skiing operates from the middle of April to the end of May.

The landscape of Senjōjiki Cirque and its formation

There are several glacial landforms confirmed near Mount Hōken, such as Senjōjiki cirque, Nogaike cirque, and Snnosawa cirques. Mount Hōken itself is a

pyramidal peak A pyramidal peak, sometimes called a glacial horn in extreme cases, is an angular, sharply pointed mountain peak which results from the cirque erosion due to multiple glaciers diverging from a central point. Pyramidal peaks are often examples o ...

made by glacial-erosion. Senjōjiki Cirque is located on the top of Nakagoshodani Valley. It forms typical cirque landscape, with flat cirque bottom, steep cirque wall with naked rock. The bottom of the cirque is about 2600m above sea level. 11

terminal moraine A terminal moraine, also called end moraine, is a type of moraine that forms at the terminal (edge) of a glacier, marking its maximum advance. At this point, debris that has accumulated by plucking and abrasion, has been pushed by the front edge ...

s are confirmed around the cirque bottom. Geologist Tatsuto Aoki examined glacial deposits from moraines of Senjojiki and Nogaike cirques, and found they were created 17 to 25 thousands year ago, at the time of the last maximum

glacial age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gree ...

Plants around Senjōjiki Cirque

In summer, Senjōjiki Cirque is filled by alpine flowers. Communities of

Veratrum viride ''Veratrum viride'', known as Indian poke, corn-lily, Indian hellebore, false hellebore, green false hellebore, or giant false-helleborine, is a species of ''Veratrum'' native to eastern and western (but not central) North America.Flora of North ...

, Trollius riederianus var. japonicus, Geum pentapetalum,

Anemone narcissiflora ''Anemonastrum narcissiflorum'', the narcissus anemone or narcissus-flowered anemone, is a herbaceous perennial in the genus ''Anemonastrum'' and the buttercup family. Basionym: ''Anemone narcissiflora'' Hook. & Arn. Description Plants grow ...

and others are seen. Botanist Takeo Hayashi confirmed 128 species around Senjōjiki Cirque.

Avalanches

Because of the landscape, avalanches often occur. On 4 January 1995, 6 people were killed in one such event.The Yomiuri Simbun 6 Jan.1995

References

{{coord, 35, 46, 47.35, N, 137, 48, 43.61, E, region:JP, display=title Cirques Kiso Mountains Japan Alps Landforms of Nagano Prefecture

The landscape of Senjōjiki Cirque and its formation

Plants around Senjōjiki Cirque

Avalanches

See also

References