Parts Of The Earth Flashcards
What makes waves change path
Contact with land
vibrations that travel through earth carrying the energy released during an earthquake
Seismic waves
Three ways geologists learn about the earths interior
Core samples
Study rocks pushed to the surface
Lab experiments
A force pressing on an area
Pressure
The three layers of the earth
Crust, core, mantle
Does pressure increase or decrease as you go deeper into the earth
Increase
Does temperature increase or decrease as you go deeper into the earth
Increase
Name the thickness, composition and state of the earths crust
Thickness 0-100 km
Composition
State - solid
Name the thickness, composition and state of the earths mantle
Thickness - 3000 km
Composition -
State - solid
Name the thickness, composition and state of the earths outer core
Thickness 2258 km
Composition - iron and nickel
State - liquid
Name the thickness, composition and state of the earths inner core
Thickness - 1222 km
Composition - iron and nickel
State - solid
A rigid layer made up of the uppermost part of the mantle and the crust
Lithosphere
The soft layer of the mantle on which the lithosphere floats
Asthenosphere
How does the core affect the magnetic field
Movement of the core creates the magnetic field
Uses a computer to turn seismic movements into 3d images
Seismic tomography
Process by which molten material adds new oceanic crust to the ocean floor
Sea floor spreading
Explain movement of sea floor spreading
Older strips of rock move outward from either side as new molten material erupts and hardens
Give three sources of evidence for sea floor spreading
Pillow lava
Magnetic stripes
Drilling samples
The process by which oceanic crust sinks beneath a deep ocean trench and back into the mantle at a convergent plate boundary
Subduction
How is the ocean floor renewed? How long does it take?
Time for rock to form at the ridge, get pushed out and sink into a trench
200 million years
Will an ocean with many trenches grow or shrink
Shrink
A section of the lithosphere that slowly moves over the asthenosphere, carrying pieces of continental and oceanic crust
Plates
A plate boundary where two plates move away from each other
Creates rifts/volcanoes
Divergent boundary
A plate boundary where two plates move toward each other
Creates mountains
Convergent boundaries