GEO quiz 2 Week 6 – Flashcards

the eruptive processes at work the types and amounts of gases dissolved in the magma the water content of the magma temperature and silicon content of the magma

lava viscosity proportion of pyroclastic debris included in the edifice local variations in the tilt of the land surface the explosive nature of the eruptions that produce the shield

Composite cones are created by lava composition alternating between basalt and rhyolite. Composite cones typically are interlayered with lava flows from nearby shield volcanoes. Composite cones are created by a mixture of explosive activity and lava flows. The lavas in composite cones are typically rhyolitic in composition.

ash is blown out of a vent and onto the side of the volcano ash and other pyroclastic ejecta become saturated with water a lateral blast spreads ash across a large area a lava flow breaks apart on the steep portion of a composite cone

A volcano sometimes swells as lava moves into the edifice. Volcanic eruption is more likely as an area undergoes tectonic uplift. Seismic activity occurs as the volcano rises. Topographic monitoring reveals the likelihood of lahar generation.

The geologic history helps to determine whether evacuation is necessary. The geologic history reflects the history of subduction beneath a volcano. The geologic history is an important indicator of seismic activity. The geologic history reveals the frequency and style of eruptions.

moving magma causes earthquakes earthquakes and dangerous volcanoes are both associated with subduction zones seismic activity indicates emission of volcanic gases earthquake usually cause the volcanic summit to collapse, setting of an eruption

Mt. Rainier Mt. St. Helens Mount Shasta Yellowstone

a'a breccia pahoehoe tuff

Caldera Cinder Cone Composite Volcano Shield Volcano