Indigirka River - Mouths of The Indigirka

Mouths of The Indigirka

The Indigirka forms a large delta, consisting of a number of streams (each one being labeled on Russian maps as a protoka (river arm)) and islands. About 100 km before reaching the East Siberian Sea (70°48′45″N 148°54′58″E / 70.8126°N 148.9162°E / 70.8126; 148.9162), the river splits into two major northeast-flowing streams. The left (westernmost) arm is known as the Russko-Ustyinskaya Protoka; the right arm, the Srednyaya Protoka (Russian for the "Middle Arm"). Further downstream, the third major arm, the Kolymskaya Protoka splits off the Srednyaya Protoka as its right (eastern) distributary, thus justifying the "middle" moniker for the Srednyaya Protoka.

While Srednyaya Protoka means the "Middle Arm", the names of the main western and eastern arms indicate their relative location as well. The Kolymskaya Protoka, or Kolymskoye Ustye is the arm one located on the eastern side, i.e. the "Kolyma side" of the delta (the arm closest to the Kolyma, the eastern neighbor of the Indigirka). The Russko-Ustyinskaya Protoka, apparently known earlier as simply Russkoye Ustye is the arm one located on the western side, i.e. the "Russian side" of the delta (meaning, the side closest to the (European) Russia). These days the name of the Russko-Ustyinskaya Protoka appears as if it were formed from the name of the old Russian village Russkoye Ustye situated there, but originally the opposite is likely to have been the case, the village being named after the river arm (the Russkoye Ustye) on which it was located.

Several flat islands are formed by the channels of the delta. Listed from the east to the west, the major ones are:

• Usun-Ary 71°23′13″N 151°15′18″E / 71.387°N 151.255°E / 71.387; 151.255 lies longitudinally along the coast east of the Srednyaya mouth. It is 12 km long and 2.7 km wide.
• Uparovskiy Island 71°34′55″N 151°11′46″E / 71.582°N 151.196°E / 71.582; 151.196 lies completely detached 11 km offshore from the Srednyaya mouth. It is about 2 km long and 1 km wide.
• Ploskiy Island 71°28′48″N 150°53′24″E / 71.480°N 150.890°E / 71.480; 150.890 is the farthest offshore of a cluster of islands at the Srednyaya mouth. It is C-shaped and about 3 km long.
• Bolshoy Fedorovskiy 71°31′59″N 150°30′36″E / 71.533°N 150.510°E / 71.533; 150.510 lies between the two mouths of the Indigirka. It is 6 km long and has a maximum width of 4 km.
• Vkodnoy and Oleniy islands lie right at the Prot. Russko Ust'inskaya mouth 71°32′46″N 150°15′58″E / 71.546°N 150.266°E / 71.546; 150.266. Both are of similar size, about 4 km in length.
• Krestovyy Island 71°26′49″N 149°45′58″E / 71.447°N 149.766°E / 71.447; 149.766 lies quiet isolated directly to the south of the Lopatka Peninsula, 10 km offshore to the NW of the main Indigirka mouths. It is 6 km long and 1.6 km wide.