Ch. 3Ch. 3Sec. 3 Sec. 3

Volcanic Volcanic eruptionseruptions

Pele's hairPele's hair• Thin strands of volcanic glass drawn out from molten

lava have long been called Pele's hair, named for Pele, the Hawaiian goddess of volcanoes.

• A single strand, with a diameter of less than 0.5 mm, may be as long as 2 m.

• The strands are formed by the stretching or blowing-out of molten basaltic glass from lava, usually from lava fountains, lava cascades, and vigorous lava flows (for example, as pahoehoe lava plunges over a small cliff and at the front of an aa flow).

magma chambermagma chamber

ventvent

pipepipe

Erupting volcano labeling activity

Side vent

side vent

1.As magma rises to surface pressure of surrounding rock on magma decreases

2.Dissolved gases expand forming bubbles

3.Cause enormous force causing eruption

pyroclastic flow•explosive eruption

•hurls out ash, gases, cinders, & bombs

http://www.youtube.com/watch?v=WxlRpuTed6g

This car is covered with volcanic dust spewed from Mt. Pinatubo, in the Phillippines.

volcanic bomb

Volcano hazards1. jets crash

2. landslides & avalanches

3. hard to breathe

4. mudflows

obsidian• forms when lava cools very quickly

•smooth, glossy surface

• Definitions• crust - Earth's outermost, rocky layer. • lava - molten rock; it usually comes out of erupting volcanoes.• magma chamber - contains magma (molten rock) deep within the

Earth's crust. • side vent - vent in the side of a volcano. • vent - opening in the Earth's surface through which volcanic materials

erupt.

pipe

side vent

magma

chamber

magma chamber

pocket beneath the surface in which magma collects

pipe

long tube in ground that connects magma chamber to Earth’s surface

vent

opening thru. which gas & lava leave volcano

vent crater

crater

bowl-shaped area that forms at top of volcano around central vent