Volcano Golovnina
Sakhalin Oblast, Kuril Islands, Kunashir Island, Russia.
Description:
On the island of Kunashir there is an active volcano Golovnina. It is the southernmost volcano of the Kuril Islands, its last eruption occurred in 1998.
The volcano is located in a caldera with a diameter of up to 4.7 kilometers, surrounded by a crest with a height of 541 meters. At the bottom of the caldera there are 2 explosive craters with lakes Boiling and Hot and 4 volcanic domes.
In the caldera beat hot keys, steam cycle jets and mud boilers. In their chemical composition there are sulfurous gases, carbon dioxide, hydrogen chloride and hydrogen sulfide. The chloride-sulphate composition of hot springs and lakes is due to the fact that gases dissolve through water. Sulfur and its compounds with water metals constantly fall out - the surface of the Boiling Lake is covered with black sulfide-sulfur foam, the shores of the lakes are covered with yellowish-black sand.
The volcano arose at the bottom of the sea, throwing a large amount of pumice. From this grew a large cone, but due to new eruptions and emptying of the magmatic hearth, as a result of the collapse, in the place where there was a volcanic mountain, there was a volcanic basin, which filled the waters of the lake. The waters came out of the caldera into the Sea of Okhotsk, after which extrusive domes grew in the caldera. They grew and exploded. In one of these craters appeared Boiling lake. All this happened hundreds and thousands of years ago.