Volcanic Landform-Crater, Geyser, Caldera (in Hindi)

Lesson 5 of 7 • 21 upvotes • 10:38mins

R K Shukla

Caldera Lake After the eruption of magma has ceased, the crater frequently turns into a lake at a later time. This lake is called a ‘caldera’. Examples: Lonar in Maharashtra and Krakatao in Indonesia. Geyser fumaroles (also called solfataras), and hot springs are generally found in regions of young volcanic activity. Surface water percolates downward through the rocks below the Earth's surface to high-temperature regions surrounding a magma reservoir, either active or recently solidified but still hot. There the water is heated, becomes less dense, and rises back to the surface along fissures and cracks. Sometimes these features are called "dying volcanoes" because they seem to represent the last stage of volcanic activity as the magma, at depth, cools and hardens. Eruptinggeysers provide spectacular displays of underground energy suddenly unleashed, but their mechanisms are not completely understood. Large amounts of hot water are presumed to fill underground cavities. The water, upon further heating, is violently ejected when a portion of it suddenly flashes into steam. This cycle can be repeated with remarkable regularity, as for example, at Old Faithful Geyser in Yellowstone National Park, which erupts on an average of about once every 65 minutes.