chapter 25.3 and 25.4 Flashcards
what is the boundary that marks the density change between layers?
discontinuity
how are discontinuities identified?
by using seismic waves
what is a shadow zone?
where no seismic waves have been recorded
what is another term or name for shadow zone?
dead zone
what are the degrees that shadow zones fall between?
105 and 140 degrees
is the outer core a solid or a liquid?
liquid
is the inner core a solid or a liquid? why?
solid because the pressure
what makes up the lithosphere
the crust and uppermost mantle
what is the asthenosphere?
plastic-like layer which earth’s plates move
what element make up the mantle?
calcium, aluminum, iron, and magnesium
which elements make up the core?
iron and nickle
viscosity
the measure of a fluid’s resistance to flow
silica
chemical compound silicon dioxide which is a common ingredient in most magma
cinder cone volcanoes
tend to be small, have heights in the hundreds of meter range, and have short eruption cycles
shield volcanoes
broad, flat structures composed of layer upon layer of lava flows
composite volcanoes
large and steep-sided, often thousands of meters high and tens or kilometres across the base, and composed of both layers of lava and ash
what is molten or liquid rock stored inside earth called?
magma
where is the ring of fire located?
Pacific ocean
what forms when tectonic plates collide along subduction zone
volcanoes
what two specific locations have volcanic activity do to divergence?
Mid-Atlantic ridge
East African Rift Valley
are hot spots stationary?
yes
what are created from hot spots?
islands (the Hawaii islands)
if a viscosity is higher, is it going to flow slower or faster?
slower
if magma has higher viscosity, is it going to have more silica?
yes
what is pyroclastic material?
solid material that erupts from a volcano
what is the smallest type of pyroclastic material?
ash
what is the biggest type or pyroclastic material?
blocks and bombs
what types of gasses come from volcanoes
water vapor, carbon dioxide, and something else
how are volcanoes classified
size
shape
materials that erupt
what are the three types of volcanoes?
cinder cone
composite
shield
