General Knowledge

A large steep-sided volcano consisting of layers of ash, fragmental debris and lava Stratovolcanoes

A mudflow associated with volcanic action or involving volcanic materials Lahar

The amount the fault or ridge moves away from its point of origin (aka displacement) Offset

Component of stress perpendicular to the earth’s planar surface (force keeping the boulder/grain from moving) Normal Stress

A mass of liquid of partially solidified rock that is ejected from a volcano Bomb

A flow involving movement of broken rock, with little sand or mud, and particle-particle contact; usually developed in gravel or sand Grain Flow

Relatively slow movement of land, typically at rates of cm/yr Subsidence

A mass of cold, solid rock ejected from a volcano Block

Fine materials (dust, ash, and cinders) produced by volcanic action Tephra

An elevation that a stream cannot erode past, controlled by level of the body of water which the stream discharges into Base Level