Transcript 7th Grade Science

What is a volcano?
• A weak spot
in the crust
where magma
has come to
the surface.
• EX:
http://alaskadestination.com/alaska-volcano-images/
What is volcanism?
• any phenomena
associated with
volcanic activity.
• EX: (next slide)
• What volcanic
phenomena have
you heard of?
What are some of the things that can
happen during an explosive eruption ?
• Explosion breaks lava
into fragments of
different sizes.
a. volcanic ash
b. cinders
c. bombs
http://www.gc.maricopa.edu/earthsci/imagearchive/b
ombs.htm
• Pyroclastic flow: a
mixture of hot gases,
ash, cinders, and
bombs.
http://www.volcano.si.edu/volcanoes/region15/peru/ubinas/3110ubi7.jpg
What is pahoehoe?
• Lava that flows
easily and
hardens into a
rippled surface.
• EX:
http://seismo.berkeley.edu/~manga/EPS214/rope.jpg
What is A’a?
• Flows slowly
and hardens
into rough
chunks.
• EX:
http://www.decadevolcano.net/photos/keywords/a_a_lava.htm