Kosheleva Volcano

Kosheleva Volcano (Вулкан Кошелева) is an active volcanic massif in the south of Kamchatka Krai, in the Ust-Bolsheretsky municipal district, within the Yuzhno-Kamchatsky nature reserve and part of the UNESCO World Heritage site "Volcanoes of Kamchatka". The massif rises in the Kambalny range near the Sea of Okhotsk coast and covers roughly 130 square kilometers.

What it is

Kosheleva is not a single cone but a complex of five volcanoes of different ages: the oldest Ancient Kosheleva shield volcano, the Western Kosheleva stratovolcano with an erosional caldera, the cone-shaped Valentin stratovolcano with its own crater, the flat-topped Eastern Kosheleva stratovolcano, and the Central Kosheleva volcano with an active crater. The Central Kosheleva volcano reaches an absolute height of 1,500 meters, and its crater measures 2–2.5 kilometers across. The massif began forming in the early Pleistocene, and its growth has continued through the Holocene into the present.

History

The last major eruption of Kosheleva Volcano is dated to the late 17th century, as recorded by the Kamchatka historian P. T. Novograblenov. An explosion crater measuring 150 by 300 meters survives on the southeastern slope, and the slopes of the Eastern Kosheleva volcano are covered with deposits from that eruption — pumice, cinder and lava fragments 0.5 to 1 meter thick.

Thermal fields

Today the volcano is defined by intense fumarolic and hydrothermal activity concentrated in two thermal fields. The Upper Kosheleva field, also known as Gremuchie Klyuchi (Roaring Springs), lies in the crater of the Valentin volcano at an elevation of 1,250 meters and covers 3.3 square kilometers: more than forty jets of superheated steam escape here at temperatures of 120–153 °C, with hydrogen sulfide dominating the gas composition. The Lower Kosheleva field sits lower, at 750–800 meters, in the erosional basin of the Western Kosheleva volcano, where numerous boiling water and mud pots reach water temperatures of 80–90 °C, and the gases are rich in methane.

Several rivers originate from the craters of the massif: the Levaya Pauzhetka flows from the crater of the Central Kosheleva volcano, the Pravaya Shumnaya from the crater of the Valentin volcano, and the Levaya Shumnaya from the basin of the Western Kosheleva volcano.

Getting there

Kosheleva Volcano lies within the Yuzhno-Kamchatsky nature reserve and can only be reached by an off-road vehicle, usually starting from the settlement of Ozernovsky. The drive to the foot of the volcano's western spur takes 2.5 to 3 hours, followed by about an hour's hike up to the Lower Kosheleva hot springs. The best time to visit is from July 1 to September 10, once the snow has melted and the roads are passable.