Volcanism
Volcanic activity refers to eruption of magmas to the earth surface and occurs usually around unstable plate boundaries. Volcanic activity, together with seismic activity, is very violent and destructive natural process and provides a clue that the earth is alive.
Volcanic ejecta are materials that are thrown out of volcanoes, including volcanic gas, lava pyroclastic materials.
Volcanic GasVolcanic gases are a variety of gaseous substances separated from magma. Main components include water vapor (H2O), carbon dioxide (CO2), sulfur dioxide (SO2), hydrogen sulfide (H2S), carbon monoxide (CO), hydrogen chloride (HCl), hydrogen fluoride (HF) and so on.
LavaLava flow is classified according to density and other physical properties of erupting magmas.
Pyroclastic MaterialsPyroclastic materials refer to fragmental solid materials produced by volcanic eruption.
Volcanic bombs are pyroclastic materials larger than 64 mm in diameter and form when a volcano ejects viscous fragments of lava during an eruption. Bombs show a variety of shape including bread-crusted, cow pie, fusiform, ribbon and cabbage.
Pahoehoe lava flow with a ropy surface
Transitional lava flow between pahoehoe and aa lava flow
Aa lava flow showing a rough rubbly crust
Volcanic clast
Volcanic ash
Volcanic lapilli
Volcanic block and bomb
Spheroidal bomb
