Pacific Ocean closed loop of the andesite line are most of the deep troughs, submerged volcanic mountains, and oceanic volcanic islands that characterize the Pacific basin. Here basaltic lavas gently flow out of rifts to build huge dome-shaped volcanic mountains whose eroded summits form island arcs, chains, and clusters. Outside the andesite line, volcanism is of the explosive type, and the Pacific Ring of Fire is the world's foremost belt of explosive volcanism. The Ring of Fire is named after the several hundred active volcanoes that sit above the various subduction zones. The Pacific Ocean is the only ocean which is almost
Circum-Baikal Railway Trans-Siberian railway on either side of Baikal was linked, and began to be used to transport goods and passengers. The Circum-Baikal was called the "golden buckle on the steel belt of Russia". Initially, only one track was built; from 1911 to 1914 the construction of a second track was undertaken, which increased capacity of the Circum-Baikal to 48 pairs of trains a day. In this stage of the construction of bridges and other engineering structures reinforced concrete was introduced as a new material. As part of these works, considerable attention was paid to the construction of stations and station towns.