The deepest canyon on EarthNamcha Barwa (7782m) and its twin Gyalha Peri (7294m) are two Himalayan giants located in the eastern part of Tibet (Nyingchi / Nyingtri Prefecture).
The distance between the two peaks is only 22km, but they are separated by the deepest and longest canyon on Earth formed by the Yarlung Tsangpo (Brahmaputra) river on its way through the Himalaya towards the Bay of Bengal. The maximal depth of the canyon varies according to the different sources and methods of measurement, but is generally given at around 5300m (some sources give an inflated depth up to 6009m...). A fairer method might be to draw an imaginary rope between the two summits, and measure the vertical drop where the rope is above the river; with such method, the canyon would still have an impressive 4'800-4'900m depth!
Namcha Barwa (7782m, Latitude 29°37'54" Longitude 95°03'18")Namcha Barwa (also spelled Namjagbarwa Feng) culminates at 7782m above sea level and is the world's 28th highest mountain (with prominence threshold of 500m). It is also the highest mountain in the eastern Himalaya. Namcha Barwa has an extreme prominence of 4106m, making it the third most prominent mountain in the Himalaya behind Everest and Nangba Parbat.
During 16 years, Namcha Barwa hold the honorific title of the highest unclimbed mountain in the world, after slighter higher Batura Sar (7795m) in Pakistan was climbed by a German expedition in June 1976. Namcha Barwa was first surveyed in 1912 by the British, but remained untouched until the eighties, when Chinese expeditions made several unsuccessful attempts.
In 1990, a first joint Japanese-Chinese expedition reached the subsidiary summit Naipun Peak (Nai Peng, Naipung, Nepen, Napung) on Namcha Barwa south ridge and even used aircrafts to scout a possible route on this huge and complex massif.
One year later, the expedition returned to the mountain, and despite the early death of one Japanese member in an avalanche on 16 October 1991, the team continued its assault until running out of food and equipment. The expedition finally withdrew on 24 November after having reached an altitude of 7460m.
For the third attempt in 1992, the same Japanese-Chinese expedition installed BC on 14 September and after 6 weeks of siege on the south ridge, 11 out of the 12 climbing members reached the summit on 30 October. Namcha Barwa was not any more virgin, and Gangkhar Puensum (7570m) at the Bhutan-Tibet border became the highest unclimbed mountain in the world, holding this title until today.
After the successful 1992 expedition, no other ascent of Namcha Barwa has been reported.
The Namcha Barwa massif counts at least 4 unclimbed summits with a prominence superior to 150 metres (source www.8000ers.com):
1) Namcha Barwa II, altitude 7146m, prominence 166m, Lat approx. 29°39'00"N, Long approx. 95°01'39"E, located 3.5km NW of Namcha Barwa I
2) Sanglung, altitude 7095m, prominence 995m, Lat 29°39'48"N, Long 95°08'12"E, located 9km NE of Namcha Barwa I. Sanglung is currently (August 2011) the 10th highest unclimbed mountain in the World with a prominence cut-off of 500m.
3) Langjiapu, altitude 6936m, prominence 236m, Lat approx. 29°39'29"N, Long approx. 95°00'17"E, located 5.5km NW of Namcha Barwa I.
4) Sanglung West, altitude 6810m, prominence 190m, Lat approx. 29°39'41"N, Long approx. 95°07'02"E, located 7km NE of Namcha Barwa I.
Gyalha Peri (7294m, Latitude 29°48'54" Longitude 94°58'18")Gyalha Peri (also spelled Gyala Peri or Gyalha Bairi Feng), could be considered as the twin of Namcha Barwa, as only 22km separate the two peaks in direct line...
But as they are separated by the deep Yarlung Tsangpo canyon, both peaks have a huge prominence (2942m for Gyalha Peri and 4106m for Namcha Barwa) and have different parents. It would actually be a several thousand kilometres journey across the whole Himalaya to join them by following the highest ridge connecting the two peaks: Namcha Barwa has Everest (800km to the west) as parent mountain, while the prominence parent for Gyalha Peri is 1100km distant Dhaulagiri (its encirclement parent, K2, is even much further west...).
Gyalha Peri has only been climbed once in August 1986 by a Japanese expedition.
Tiba Kangri (6846m) & Sendapu (6812m)Another highly prominent Peak is Tiba Kangri (Latitude 29°50'00" Longitude 94°52'00"), which almost makes it in the list of the ultra-prominent peaks with a prominence of 1470m. It is located just 10km west of Gyalha Peri.
Sendapu, also called Sengdom Pu or Sedong Ri (Latitude 29°50'24" Longitude 94°56'33") is located on the ridge connecting Tiba Kangri and Gyalha Peri. It has a prominence of 508m.
Both Tiba Kangri and Sendapu are unclimbed.