Transcript Earth`s Interior notes

Chapter 5.1 Notes
Earth’s Interior
Exploring the Earth
• Geologists use two types of evidence to
learn about the Earth’s interior:
-direct evidence from rock samples
-indirect evidence
from seismic waves
*the deeper into the Earth you go, the
greater the temperature and pressure
Layers of the Earth
• The Earth is divided into four layers:
-crust
-mantle
-outer core
-inner core
Layers of the Earth
• The crust:
definition – a
that includes both
(continental crust)
(oceanic crust)
layer of solid rock
dry land
and the ocean floor
Layers of the Earth
• The crust:
Layers of the Earth
• The crust:
definition – a
layer of solid rock
that includes both
dry land
(continental crust)
and the ocean floor
(oceanic crust)
thickness - the crust can range between 5 and 70
kilometers thick
-thickest under mountain ranges
-thinnest under the ocean
composition –
-continental crust mainly made of granite
-oceanic crust mainly made of basalt
Layers of the Earth
• The crust:
Layers of the Earth
• The mantle:
definition – The
mantle is made of
solid rock that is
very hot. It is
separated into 3
layers. The
lithosphere, the asthenosphere and lower
mantle.
thickness – almost 3,000 kilometers
composition – silicon, magnesium and iron
Layers of the Earth
• The mantle:
-lithosphere
– solid rock, similar to the crust
- temperature is between
1400°C and 3000°C
-the deeper you go, the
rock begins to become
“softer”
Layers of the Earth
• The mantle:
-athenosphere – increased temperature and
pressure continue to
soften the rock
-temperature is at or
above 3000°C
-convection currents
occur in this section
-hotter rock rises and
cooler rock sinks
Layers of the Earth
• The mantle:
-lower mantle – solid layer of rock that
surrounds the outer
core
-temperature reaches
almost 4000°C
Layers of the Earth
• Outer core:
definition – the
layer of liquid
around the inner
outer core is a
rock the moves
core
thickness – almost 2,300 kilometers
composition – mainly iron and nickel, some
sulfur, oxygen and silicon
temperature – between 4000°C – 5000°C
Layers of the Earth
• Inner core:
definition – The
solid ball of
extreme
pressure.
inner core is a
metal, due to the
temperature and
thickness – over 1,200 kilometers
composition – mainly iron and nickel, some
sulfur, oxygen, carbon and silicon
temperature – between 5000°C – 6000°C