products of volcanoes Flashcards
list of products
volcanic gas
lava flow
pyroclastic material
what is a volcano
a vent at the surface of the earth through which magma and other volcanic materials are ejected
what are characteristics of mafic lavas
low viscosity
thin
spread furthest
what are the two types of mafic lava?
aa
pahoehoe
what are characteristics of aa lava flow surfaces
rough blocky jagged surface
what are characteristics of pahoehoe lava flow surfaces
smooth or ropey surface
which out of aa and pahoehoe is more viscous
aa
pahoehoe is less viscous but becomes more viscous as it cools sometimes becoming aa lava
what are volcanic gases
gases dissolved in magma while under pressure at depth. when pressure decreases nearer suface, gases are released by an eruption
what do volcanic gases consist of
water vapor (ABOUT 70%)
CO2
N
SO2
gases combine with H and H2O to form toxic compounds. can cause acid rain near volcano
what are characteristics of intermediate and silicic lavas
viscous
short flow distance
can form domes within crater
often shows flow banding
what are pyroclastic materials?
magma forcefully/explosivley ejected into atmospere as particles calles pyroclasts
what are some pyroclasts
ash lapilli bombs and blocks nuée ardentes pumice- travels far, floats
what is volcanic ash
smallest particles (
what is lapilli?
particles 2-64mm
form lapilli tuff
what are bombs and blocks
coarsest particles >64 mm
form pyroclastic rock AGGLOMERATE around crater
