GEOLOGY

Detailed explanation-1: -As a lava flow spreads out from its source at a volcanic vent, the surface cools and hardens while the flow remains hot inside. Lava tubes are winding channels inside the flow where lava runs hottest and most fluid.

Detailed explanation-2: -Magma leaves the volcano through the vent and becomes lava. They are covered by lava as it pours out of a vent and called a lava flow.

Detailed explanation-3: -When a volcano erupts, the molten rock (or magma) that comes out of the Earth is called lava. Because lava is so hot (more than 1, 100 degrees C, over 2, 000 degrees F), it remains molten and flows across the ground until it cools and hardens into rock.

Detailed explanation-4: -Lava cools to form volcanic rock as well as volcanic glass. Magma can also extrude into Earth’s atmosphere as part of a violent volcanic explosion. This magma solidifies in the air to form volcanic rock called tephra. In the atmosphere, tephra is more often called volcanic ash.

Detailed explanation-5: -A lava flow is an outpouring of lava during an effusive eruption. (An explosive eruption, by contrast, produces a mixture of volcanic ash and other fragments called tephra, not lava flows.)