chapter 25.3 and 25.4 Flashcards
(29 cards)
what is the boundary that marks a density change between layers
discontinuity
how are discontinuities identified
by using seismic waves
what is the shadow zone
an area where no seismic waves have been recorded
what is another term for shadow zone
dead zone
what are the degrees that shadow zones fall between
105 and 140
is the outer core a solid or a liquid
liquid
is the inner core a solid or a liquid? why?
solid, because of pressure
what makes up the lithosphere
the crust and the upper mantle
what is the asthenosphere
plastic like layer which earths layers move on
which elements make up the mantle
calcium, aluminum, iron, and magnesium
which elements make up the core
iron, nickel
the measure of a fluids resistance to flow
viscosity
the chemical compound silicon dioxide, SIO2, which is a common ingredient in most magma
Silica
tend to be small, heights in the hundreds meters ran8ge and have short eruption cycles
Cinder cone volcanoes
are broad, flat structures composed of layer upon layer of lava flows
shield volcanoes
are large steep-sided, often thousands of meters high and tens of kilo meters across the base
composite volcanoes
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 zones
volcanoes
which two specific locations have volcanic activity due to divergents
mid Atlantic ridge, east African rift valley
are hotspots stationary? what are created from hots pots
Yes, islands
if a viscosity is higher is it going to flow slower or fast?
slower
if magma has a high viscosity is going to have more or less silica
more
what is pyroclastic material
any solid material that erupts from a volcano
