United States Geological Survey
Hawaii Volcano Observatory
Flood basalt plateau
Fluid basaltic lava covering vast areas
Typically form over hotspots. Made from fluid lava.
A broad circular depression in a volcano
Propelled magma and ash that pile up by a vent
ash, cinders, and pumice formed when magma explodes.
Like toothpaste squeezed from a giant tube. Piles up around a lava vent.
Built with alternating layers of tephra and lava.
Depression at the site of summit eruptions.
Swirling cloud of pumice, ash, and hot gas.
Passage through which magma is erupted.
Young lava flows
lavas from recent eruptions exposed on the surface.
Sites of eruptions on the flanks of the volcano.
Debris from recent exploive eruptions.
Debris from earlier explosive eruptions.
Molten rock below ground. Consists of lilquid, suspended crystals, and gases.
Magma that erupts non-explosively.
How much magma is erupted
The opposite of fluid. Slow moving.
The amount of gas and how easily it can escape.
Where most volcanoes occur
Hard, dense, dark volcanic rock composed of olivine, pyroxene, and plagioclase. Often has a glassy appearance.
Droplets of basaltic lava that mold into tear-shaped glassy beads as they fall.
Spun hairlike filaments of volcanic glass formed naturally from molten lava that hardened while subjected to high winds.
Ring of Fire
An extensive zone of volcanic and seismic activity that roughly coincides with the borders of the Pacific plate.
Strong, low frequency sound waves caused by tectonic plate movement.