Science Ch. 5 Flashcards
Scientists use _______ _______ and ______ ______
direct evidence, indirect evidence
3 layers of the Earth: (from land to center)
crust-mantle-core
The layers of the Earth vary in ____, ____, _____, and _____
size, composition, temperature, and pressure
temperature:
increases as you go further in the Earth (closer into the Earth)
pressure:
increases as you go deeper
How?
The rocks above you pile up.
crust:
a layer of solid rock w/ dry land and ocean floor
thickest under mountains and thinnest under oceans
oceans=
basalt
mountains=
granite
mantle:
upper+lower parts below crust
upper mantle:
lithosphere
athenosphere:
means soft
outer core:
layer of molten material
inner core:
dense ball of solid material (extreme pressure causes iron atoms to stay together
radiation:
transfer of energy via space
ex) sun
conduction:
heat transfer via material
convection:
heat transfer via fluid/liquid/gas
convection currents:
flow that travels heat with a fluid
convection currents in earth:
heat from core circulates
In 1910, ____ ______ hypothesised that Earth’s continents had moved
Alfred Wegener
Alfred’s hypothesis stated all the continents were one together, then they…
moved and drifted apart
the idea of the continents moving is…
continental drift
The continents drifted and combined to become a supercontinent called _______
Pangaea
Wegener gathered evidence from:
land features, fossils, and climate change
Wegener’s hypothesis was ______
rejected
_____ and ______ were both animals from the Pangaea
Mesosaurus + Lystrosaurus
Wegener could not provide the evidence of what ______ ___ _______ ______
pushed or pulled continents
a _______ was a fern-like plant on many continents
glossopteris
Deep ocean trenches:
When the ocean floor goes into an underwater canyon
Subduction:
When an ocean sinks beneath into a mantle
Sonar:
detecting devices that absorb sound waves
Mild- ocean ridge:
ripples/cures in an ocean
Sea-floor spreading:
when the ocean floor opens allowing new crust to come in
3 types of Evidence for Sea-floor spreading:
1) Molten Material
2) Magnetic Stripes
3) Drilling Samples
In 1968, Glomer Challenger (a submarine) drilled into the ocean floor and found proof of sea floor spreading, and drilling became the #1 evidence. How?
When he drilled a rock, the youngest one was in the middle proving of sea-floor spreading
The process of seafloor spreading takes ____ __ _____ __ ______
tens of millions of years
