Class+notes+III

Magma - Melted rock under the Earth’s surface

Lava – Melted rock on the Earth’s surface

Lahar – Hot mudflow of ash and water

Viscosity – describes the ability of a liquid to flow

Viscous – thick (high viscosity) Runny – thin (low viscosity)

Caldera – A large, steep-sided, circular, volcanic depression that forms when magma leaves an underground magma chamber and the rock above collapses.

Igneous rock – forms from magma or lava (cool and crystallizes on or below Earth’s surface)

Hot spot – a localized zone of melting in the mantle that is fixed under a plate

Volcano types T-chart should be in class notes

Ash – Fragmented volcanic material with particle sizes measuring less than 2 mm in diameter