Download 1Earths layers

Layers of the Earth
The Earth as a System
• Integrated system of rock, air, water, and living
things.
• This system is divided into four parts:
– atmosphere (air)
– hydrosphere (water)
– biosphere (living things)
– geosphere (rock)
Composition of the Earth
• Four layers:
–
–
–
–
crust
mantle
Outer core
Inner core
• Density increases
towards the center of
the Earth
Geosphere
• Solid part of the
Earth’s crust that
consists of all
rock, and the
soils and
sediments on
Earth’s surface.
• Most located in
Earth’s interior
Crust
• The crust is the layer that you live
on so it is the most widely studied
and understood.
• Two Kinds of Crust:
–Oceanic- Thin, more dense, 3-5mi
thick, made of Basalt (lots of metals)
–Continental- Thicker, less dense, 5-30
miles thick, made of granite (low
metal)
Crust
• The crust is made of the lightest
matter and the core consists of
heavy metals
• Crust is like the skin of an apple. It is
very thin in comparison to the other
three layers.
Crust
• The crust of the Earth is broken
into many pieces called plates.
The plates move along the soft
mantle which is the layer located
below the crust.
Crust
• The plates move along smoothly but
sometimes they get stuck and pressure
builds up.
Crust
The pressure builds and causes an
Earthquake as rocks break and
crack.
San Francisco City Hall after the 1906
Earthquake. (from Steinbrugge Collection of
the UC Berkeley Earthquake Engineering
Research Center)
Crust
• Thin, outer layer.
• Made up of light
elements
• less than 1% of Earth’s
mass
• 5-70km thick
Lithosphere
• Outer layer
• cool, rigid
• divided up into
huge tectonic
plates
Lithosphere
• Consists of continental,
oceanic and upper part of
mantle
• Continents composed of granitetype rock, quartz and feldspar
minerals, density+2.8g/cm3
• Oceanic crust formed of basalt;
basalt rich in iron/magnesium
minerals, density+3.0 g/cm3
• Lithosphere is rigid layer of crust
and mantle overlying partiallymolten asthenosphere
Asthenosphere
• 250 km thick
• solid, plastic layer
made of rock
• flows very slowly
and allows
tectonic plates to
move across
Mantle
• Layer beneath the
crust
• 64% of mass of Earth
• 2,900 km thick
• Made of
– lithosphere
– asthenosphere
– mesosphere
Mantle
• The mantle is the largest layer of the
Earth.
• It is made of hot, dense rock. The rock in
the mantle flows like asphalt because of
the temperature differences found in
the mantle.
• The movement of the mantle create the
movement of the Earth’s plates.
Core
• 3,248 km radius
• sphere of hot, dense
nickel and iron
• 4,000 - 5,000 °C
• 1/3 of the Earth’s
mass
• Made of
– Outer Core
– Inner Core
• Outer Core; 2,200 km
thick, outer shell,
made of liquid nickel
and iron
• Inner Core: 1,228 km
radius; a sphere of
solid iron and nickel
Core
• The core of the Earth is much
like a ball of very hot metals.
The inner core is solid metal,
surrounded by a fluid iron
outer core.
Earth’s Interior
• Core
–
–
–
–
dense
Iron and Nickel
Inner Core - solid
Outer Core - liquid
• Mantle
–
–
–
–
Less dense than core
Iron and Magnesium silicates
Mostly solid
Upper mantle is partially molten
• Crust
– Outermost layer
– Very thin and rigid
– Continental – granite
– Density = 2.8 g/cm3
– Oceanic – basalt
– Density = 3.0 g/cm3
• Be able to draw and label the three layers
of the earth (crust, mantle, and core) as
well as the 4 layers based on physical
properties (lithosphere, asthenosphere,
outer and inner core).
• Compare and contrast lithosphere and
asthenosphere… give 3 examples of candy
for each
• ADD The inner and outer core… Give three
details for EVERY LAYER– include densities`