Big Semyachik Volcano, located in the central part of the Eastern volcanic belt of Kamchatka, about 25 kilometers southeast of the caldera Uzon - a complex volcanic massif. The volcano presented a complex structure, located in the eponymous caldera, the diameter of which is 10 km away. The absolute height of the main volcanic formations around 1739 m, and the total diameter of the base of the array is 15 km away.

The sides of the caldera is very well expressed in the west and southwest of the array. As for the rest of the caldera, its caldera and cover postkaldernye education. Around it you can see a series of arc faults. Formation of the caldera emits large mass to form pyroclastic tuffs and ignimbrites sintered.

The array consists of the Big Semyachik postkaldernyh volcanic formations that fill the entire central and eastern parts of the overlapping calderas. Postkaldernye volcanic formations are represented by seven conical stratovolcanoes, the diameter of the base of each of which is from 3 to 8 km. The largest of them is - Big Semyachik (zubchatki), which occupies the eastern part of the caldera. Its altitude is 1720 m. The central part of the Grand Massif Semyachik took four of the volcano, a cone-shaped hill representing a base diameter of up to 3 km and a relative height of 500 meters.

In ancient times the height of the volcano reached 3 km, but under the influence of erosion for many years the volcano has become much lower. Climbing up the volcano peaks give stern and majestic views. The top of the volcano has a toothed shape, so he got one more local name - zubchatki.

Vulcan Big Semyachik widely-developed fumarole fumarolic and hydrothermal activity. Volcanic rocks over large areas, after changing to alunite, Opalite and kaolitov are colorful and bright color loose constitution. The most active modern fumarolic activity manifested on the ruined volcanoes seething Semyachik and Central, as well as a large area between them.