Chapter 25.3 and 25.4 Flashcards
(35 cards)
what is the boundary that marks the density change between layers?
discontinuity
how are discontinuities identified?
by using seismic waves
what are shadow zones?
areas where seismic waves aren’t recorded
what’s another term or name for shadow zones?
dead zones
between which degree ranges do shadow zones fall?
105 degrees to 140 degrees
is the outer core a liquid or a solid?
a liquid
is the inner core a solid or a liquid?
a solid
why is the inner core a solid?
it’s solid because of pressure
what makes up the lithosphere?
the crust and the uppermost mantle
what is the asthenosphere?
plastic-like layer which earth’s plates move on
which elements make up the mantle?
calcium, aluminum, iron, magnesium
what elements make up the core?
iron and nickel
viscosity
the measure of a fluid’s resistance to flow
silica
the chemical compound silicone dioxide, which is a common ingredient in most magma
cinder cone volcanoes
small volcanoes that have heights in the hundreds of meters range, and have short eruption cycles
shield volcanoes
broad volcanoes that are flat structures composed of layer upon layer of lava flows
composite volcanoes
large and steep-sided volcanoes, often thousands of meters high and tens of kilometers across the base, and composed of layers of both lava and ash
what is molten or liquid rock stored inside Earth called?
magma
where is the ring of fire located?
the Pacific Ocean
which two specific locations have volcanic activity due to divergents?
Mid Atlantic Ridge and the East African Rift
are hotspots stationary?
yes
what can hotspots create?
islands (hawaiin islands)
if the viscosity is higher, will the fluid flow more quickly or more slowly?
more slowly
if magma has a high viscosity, will it contain more or less silica?
more silica
