GEOLOGY

Detailed explanation-1: -Lava Domes-Lava domes form where thick (viscous) magma erupts to the surface forming a steep dome-shaped landform. Lava domes can form within a crater of large composite volcano .

Detailed explanation-2: -Volcanic craters may have a cone or flanks associated with the crater. There may also be flows present. Impact craters may have central peaks, ejecta, raised rims and floors that are lower in elevation than the surrounding terrain that can distinguish them from volcanic craters.

Detailed explanation-3: -During volcanic eruptions, molten magma and volcanic gases rise from an underground magma chamber, through a conduit, until they reach the crater’s vent, from where the gases escape into the atmosphere and the magma is erupted as lava. A volcanic crater can be of large dimensions, and sometimes of great depth.

Detailed explanation-4: -Crater wall material collapses where degassing is concentrated and eruptions blow out material from the crater floor. These changes sustain a crater shape similar to other summit craters that formed by collapse into an evacuated magma chamber.

Detailed explanation-5: -Most composite volcanoes have a crater at the summit which contains a central vent or a clustered group of vents. Lavas either flow through breaks in the crater wall or issue from fissures on the flanks of the cone. Lava, solidified within the fissures, forms dikes that act as ribs which greatly strengthen the cone.