Lake Akan

43°27′6″N 144°5′55″E / 43.45167°N 144.09861°E / 43.45167; 144.09861Lake typeDimicticPrimary outflowsAkan RiverCatchment area148 km2 (57 sq mi)Basin countriesJapanSurface area13 km2 (3,200 acres)Average depth17.8 m (58 ft)Max. depth44.8 m (147 ft)Water volume0.23 km3 (0.055 cu mi)Shore length125.9 km (16.1 mi)Surface elevation420 m (1,380 ft)FrozenDecember to AprilIslands4: Ōjima, Kojima, Yaitai Island, Chūrui IslandSettlementsKushiro
Ramsar Wetland
Official nameAkan-koDesignated8 November 2005Reference no.1540[1] 1 Shore length is not a well-defined measure.

Lake Akan (阿寒湖, Akan-ko) is a lake in Kushiro, Hokkaidō, Japan. It is located in Akan National Park and is a Ramsar Site.[2][3]

History

Volcanic activity formed the lake some 6,000 years ago, when a lava dam was formed. The lake used to have a clarity of 8–9 meters in the 1930s. Pollution from local hotspring resorts has decreased the transparency to 3–4 meters.[4]

Flora and fauna

The lake is famous for the marimo (Aegagropila linnaei), aggregations of algae that form into spherical shapes 2–30 cm in diameter. Other flora of the lake include the following:[4]

Kokanee salmon (Oncorhynchus nerka) are native to Lake Akan. Other fauna of the lake include the following:[4]

Climate

Climate data for Lake Akan (1991−2020 normals, extremes 1977−present)
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °C (°F) 6.1
(43.0) 		10.8
(51.4) 		16.5
(61.7) 		28.3
(82.9) 		35.5
(95.9) 		34.5
(94.1) 		34.9
(94.8) 		33.9
(93.0) 		31.4
(88.5) 		24.5
(76.1) 		19.0
(66.2) 		11.8
(53.2) 		35.5
(95.9)
Mean daily maximum °C (°F) −4.2
(24.4) 		−3.1
(26.4) 		1.4
(34.5) 		8.1
(46.6) 		15.1
(59.2) 		18.9
(66.0) 		22.3
(72.1) 		22.8
(73.0) 		19.0
(66.2) 		13.2
(55.8) 		5.8
(42.4) 		−1.4
(29.5) 		9.8
(49.7)
Daily mean °C (°F) −10.0
(14.0) 		−9.4
(15.1) 		−4.2
(24.4) 		2.3
(36.1) 		8.5
(47.3) 		13.1
(55.6) 		17.1
(62.8) 		18.0
(64.4) 		14.0
(57.2) 		7.5
(45.5) 		0.7
(33.3) 		−6.5
(20.3) 		4.3
(39.7)
Mean daily minimum °C (°F) −16.7
(1.9) 		−16.8
(1.8) 		−10.8
(12.6) 		−3.3
(26.1) 		2.3
(36.1) 		8.0
(46.4) 		12.9
(55.2) 		13.9
(57.0) 		9.3
(48.7) 		2.1
(35.8) 		−4.3
(24.3) 		−12.1
(10.2) 		−1.3
(29.7)
Record low °C (°F) −30.2
(−22.4) 		−30.7
(−23.3) 		−26.6
(−15.9) 		−20.9
(−5.6) 		−7.5
(18.5) 		−3.3
(26.1) 		1.8
(35.2) 		3.2
(37.8) 		−1.2
(29.8) 		−7.6
(18.3) 		−17.3
(0.9) 		−26.9
(−16.4) 		−30.7
(−23.3)
Average precipitation mm (inches) 63.2
(2.49) 		44.5
(1.75) 		70.2
(2.76) 		90.8
(3.57) 		105.7
(4.16) 		84.4
(3.32) 		103.2
(4.06) 		160.0
(6.30) 		165.7
(6.52) 		137.8
(5.43) 		85.2
(3.35) 		87.4
(3.44) 		1,197.9
(47.16)
Average snowfall cm (inches) 132
(52) 		96
(38) 		105
(41) 		54
(21) 		3
(1.2) 		0
(0) 		0
(0) 		0
(0) 		0
(0) 		1
(0.4) 		31
(12) 		123
(48) 		548
(216)
Average precipitation days (≥ 1.0 mm) 10.2 8.9 11.5 11.3 11.0 10.1 10.4 11.4 12.0 10.5 9.8 9.8 126.9
Average snowy days (≥ 3 cm) 12.3 10.4 12.1 7.0 0.4 0 0 0 0 0.1 3.9 13.0 59.2
Mean monthly sunshine hours 97.5 111.9 137.1 154.0 169.4 146.3 132.2 115.7 110.1 123.3 110.6 107.3 1,546
Source: Japan Meteorological Agency[5][6]


Gallery

See also

References

  1. ^ "Akan-ko". Ramsar Sites Information Service. Retrieved 25 April 2018.
  2. ^ "Data Summary: Akan-ko (Lake Akan)". World Lakes Database. International Lake Environment Committee. Archived from the original on 2012-04-20. Retrieved 2009-05-18.
  3. ^ "Ramsar Sites in Japan - Akan-ko" (PDF). Ministry of the Environment. Retrieved 24 March 2011.
  4. ^ a b c "AKAN-KO (LAKE AKAN)". World Lakes Database. International Lake Environment Committee. Archived from the original on 2012-03-05. Retrieved 2009-05-18.
  5. ^ 観測史上1～10位の値（年間を通じての値）. JMA. Retrieved March 3, 2022.
  6. ^ 気象庁 / 平年値（年・月ごとの値）. JMA. Retrieved March 3, 2022.
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