chapter 25.3 and 25.4 Flashcards
what is the boundary that marks a density change between layers?
Discontinuity
How are discontinuities identified?
By using seismic waves
What are shadow zones?
Areas where no seismic waves are recorded
What is another name for shadow zones?
Dead zone
Between what degrees do shadow zones fall?
105 to 140 degrees
Is the outer core a solid or a liquid?
Liquid
Is the Inter core a solid or a liquid and why?
Solid, because of so much pressure.
What makes up the lithosphere?
Made up of crust and uppermost mantle
What is asthenosphere?
A plastic like layer, which earth’s plates move.
Which elements make up the mantle?
Calcium,aluminum,
Which elements make up the core?
Iron and magnesium
the measure of fluids resistance to flow
Viscosity
the chemical compound silicon dioxide, SiO2, which is a common ingredient in most magma
Silica
tend to be small, have heights in the hundredths of meters range, and have short eruption cycles.
Cinder cone volcanoes
are broad, flat structures composed of layer upon layer of lava flows
Shield volcanoes
large and steep sided, often thousands of meters high and tens of kilometers across the base, and composed of layers of both lave and ash
Composite Volcanoes
What is the smallest pyroclastic material
Volcanic ash
Forms when molten rock rises from deep within Earth and erupts from a crack in the crust
Volcano
Occurs where plates separates along a mid-ocean ridge or where plates collide along a subduction zone
Volcanic Eruptions
a feature that forms when magma reaches Earth’s surface and erupts as either lava or ash.
Volcano
occurs along divergent plate boundary
Volcanic activity
What is the largest pyroclastic materials
Volcanic blocks and bombs
erupts in a variety of ways depending on magma composition and velocity
Volcano
classified according to their size, shape, and the materials that erupt.
volcanoes
