Paektu Mountain

Paektu Mountain or Baekdu Mountain (Korean: 백두산) is an active stratovolcano on the Chinese–North Korean border. In China, it is known as Changbai Mountain (Chinese: 长白山). At 2,744 m (9,003 ft), it is the tallest mountain in North Korea and Northeast China and the tallest mountain of the Baekdu-daegan and Changbai mountain ranges. The highest peak, called Janggun Peak, belongs to North Korea. The mountain notably has a caldera that contains a large crater lake called Heaven Lake, and is also the source of the Songhua, Tumen, and Yalu rivers. Korean and Manchu people assign a mythical quality to the mountain and its lake, and consider the mountain to be their ancestral homeland.

The mountain's caldera was formed by an eruption in 946 that released about 100–120 km³ (24–29 cu mi) of tephra. The eruption was among the largest and most powerful eruptions on Earth in the last 5,000 years. The volcano last erupted in 1903, and is expected to erupt around every hundred years. In the 2010s, concerns over an upcoming eruption prompted several countries to commission research into when the volcano might next erupt.^{[needs update]} The mountain is considered culturally important to multiple groups in the area, including Korean, Chinese, and Manchu people. The mountain is a major national symbol for both North and South Korea, and is mentioned in both national anthems and depicted on the national emblem of North Korea. The Manchu people also consider the mountain their ancestral homeland, and the Chinese Qing dynasty saw it as a symbol of imperial power and the mountain had been subject to territorial disputes over the past few centuries. In the late 20th century, the states of China and North Korea diplomatically agreed to joint custody.

The mountain was first recorded in the Chinese Classic of Mountains and Seas under the name Bùxiánshān (不鹹山). It is also called Shànshàndàlǐng (單單大嶺) in the Book of the Later Han. In the Book of Wei and the Book of Sui it is also referred to as Dutàishān (徒太山), which is also mentioned as Cóngtàishān (從太山) in the History of the Northern Dynasties, likely as a misspelling of Dutàishān. In the New Book of Tang, it was called Tàibáishān (太白山). The current Chinese name, Chángbáishān (长白山; 長白山; 'ever white mountain'), was first used in the Liao dynasty (916–1125) of the Khitans and then the Jin dynasty (1115–1234) of the Jurchens. The Liao Shi recorded that chiefs of 30 Jurchen tribes from Mount Changbai paid their tribute to the Liao in AD 985. According to the Song dynasty travelogue Songmo Jiwen, it was named as such because the mountain was "the abode of the white-robed Guanyin" and its birds and beasts were all white. The modern Manchu name of the mountain, which is golmin šanggiyan alin (ᡤᠣᠯᠮᡳᠨ ᡧᠠᠩᡤᡳᠶᠠᠨ ᠠᠯᡳᠨ), means 'long white mountain'.

The Korean name Baekdusan / Paektusan (백두산; 白頭山) first appears in literature in the 10th year of Seongjong of Goryeo (991) in the Goryeosa, compiled at the beginning of the Joseon period. It means 'white-head mountain'. In other records such as the Samguk yusa and the Jewang ungi it is also called Taebaeksan (태백산; 太白山), which means 'great-white mountain'. It was also occasionally called Changbaeksan (長白山) and Baeksan (白山) in the Veritable Records of the Joseon Dynasty. An alternative Chinese name, Báitóushān (白头山; 白頭山), is the transliteration of Baekdusan.

The Mongolian name is Öndör Tsagaan Aula (Өндөр Цагаан Уул), which means 'lofty white mountain'. In English, various authors have used nonstandard transliterations.

Mount Paekdu is 2,744 m (9,003 ft) tall, making it the highest mountain in North Korea and Northeast China and the highest mountain of the Baekdu-daegan and Changbai mountain ranges.

Mount Paekdu is a stratovolcano whose cone is truncated by a significant caldera. The central section of the mountain rises about 3 mm (0.12 in) per year due to rising levels of magma below the central part of the mountain. Sixteen peaks exceeding 2,500 m (8,200 ft) line the caldera rim surrounding Heaven Lake. The highest peak, called Janggun Peak, is covered in snow about eight months of the year. The slope is relatively gentle until about 1,800 m (5,910 ft). The caldera is about 5 km (3.1 mi) wide and 850 meters (2,790 ft) deep, and is partially filled by the waters of Heaven Lake.

Heaven Lake has a circumference of 12 to 14 kilometers (7.5 to 8.7 mi), with an average depth of 213 meters (699 ft) and maximum depth of 384 meters (1,260 ft). From mid-October to mid-June, the lake is typically covered with ice. Water flows north out of the lake, and near the outlet there is a 70-meter (230 ft) waterfall. The mountain is the source of the Songhua, Tumen and Yalu rivers. The Tumen and the Yalu form the northern border between North Korea and Russia and China.