ch25.3and25.4 Flashcards
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 have aren’t recorded
What is another name for shadow zones?
dead zone
Between which degrees do shadow zones fall?
105 to 140 degrees
Is the outer core a liquid or a solid?
liquid
is the inner core a liquid or a solid?
solid
What two things makes up the lithosphere?
the crust and the uppermost mantle
What is the asthenosphere?
plastic like layer on which Earths plates move
Which elements make up Earth’s mantle?
Calcium, Aluminum, Iron, Magnesium
Which elements make up the core?
Iron and Nickle
What is viscosity?
The measure of a fluids resistance to flow
What is silica?
The chemical compound silicon dioxide
what is a cinder cone volcanoe?
small and have short eruption cycles
what is a shield volcanoe?
broad with flat structures composed of layer upon layer of lava flow
What is a composite volcanoe?
large steep sided often thousands of meters high
What is molten or liquid rock stored inside earth called?
magma
Where is the ring of fire located?
along the pacific ocean shore line
which 2 specific location have volcanic activity due to divergents?
East African Rift and the Mid Atlantic ridge
Are hot spots stationary?
yes
What can hot spots create?
islands(Hawiian islands)
If the viscosity if higher will the fluid flow more quickly or more slowly?
more slowly
If magma has a high viscostiy will it contain more or less silica?
more
What is pyroplastic material?
Any solid material that erupts from a volcano
What is the smallest pyroplastic material?
volcanic ash
What is the largest pyroplastic material?
Volcanic blocks and bombs
What are the types of gases that erupt?
Water vapor, Carbon dioxide, and sulfur dioxide
What causes different styles of eruption?
magma and viscosity
Why are there different types of volcanoes?
shape, size and materials that erupt
What erupts from cinder cones?
high temperatures, low viscosity
What erupts from shield volcanoes?
high temperature, low viscosity, basaltic lava
What are composite volcanoes formed from?
Erupting pyroplastic material building up
What are the three types of volcanoes?
shield, composite, cinder cone
