Mt. Rainier National Park

Front 1

caldera

Back 1

a large basin or bowl shaped depression caused by the explosion or collapse of a volcano cone

Front 2

debris flow

Back 2

solids are at least 50 percent sand, silt, ash and clay. The debris flow is the mass wasting involving rapid flowage of debris

Front 3

Mt. Rainier is a classic example of a composite cone (also called a stratovolcano). In what way is the origin of this mountain related to the origin of other large volcanoes in the circum-Pacific “Fire Zone” (Ring of Fire)?

Back 3

Mt. Rainier is one of more than a dozen geologically young volcanoes with composite cones (stratovolcanoes) that are perched on older rocks of the Cascade Range. The fire zone is a volcanic belt that marks converging plate boundaries where oceanic crust is subducted beneath overriding continental crust or an island arc. They are almost entirely composite cones and andesitic in rock composition. Brief eruptive episodes lasting years or decades were interspersed with long periods of quiescence.

Front 4

North American plate

Back 4

located along the Pacific Northwest coastline (from British Columbia and down to northern Cali), the North American plate is westward-moving against a segment of eastward-traveling oceanic crust. East of the subduction zone along the pacific northwest coastline

Front 5

Juan de Fuca plate

Back 5

of the adjacent Pacific basin and is pulled down into the subduction zone and underneath the North American plate; from Washington and down to the Oregon-California border; west of the subduction zone along the pacific northwest coastline

Front 6

top of the subduction zone

Back 6

west of the pacific northwest coastline

Front 7

Cascade Range

Back 7

aligned at the surface over a melt zone at depth; from Washington and down through Oregon; located approximately above the zone of melting deep within the crust

Front 8

What are lahars?

Back 8

A lahar is a type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water; a destructive mudflow on the slopes of a volcano

Front 9

How do lahars form?

Back 9

Snow and glaciers; Lava flows out of open vents; floods caused by a glacier, lake breakout or heavy rainfall

Front 10

In what direction did the largest Holocene lahars originating from Mt. Rainier flow?

Back 10

Northwest

Front 11

The locations of cities such as Orting and Auburn seem to be ideal: they are built on relatively flat ground with deep soils. Are these good places to build cities? Explain

Back 11

NO. They are located on older mudflows, therefore they are more likely to experience disasters.