Download 2015 Earth`s Structure

Unit 1: Structure of the Earth
Standard:
Compare and Contrast the layers of the earth including
composition, relative temperature, and density.
What challenges stand in the way of
scientists exploring the center of the
Earth?
•
Deepest Mine
– Carletonville, South Africa 2 1/3 mile (3.8km)
•
Deepest Geological Dig
– Zapolyarnyy, Russia
•
9 miles (15km)
Deepest Ocean Dive
– Bathscaphe in Marianas Trench 6 miles
(10km)
•
Deepest Ocean Trench
– Marianas Trench, Pacific Ocean 7 miles
(11km)
What challenges stand in the way of
scientists exploring the center of the
Earth?
•
No equipment equipped to withstand the
heat, pressure, and depth of the interior of
the Earth.
•
No human can withstand the heat,
pressure, or depth of the interior of the
Earth.
The composition of the Earth
• The Earth is divided into three main layers
– the crust, the mantle, and the core- based
on the compounds that make up each
layer. A compound is a substance
composed of two or more elements. The
least dense compounds make up the crust
and mantle, the densest compounds make
up the core. The layers form because
heavier elements are pulled toward the
center of the Earth by gravity, and the
elements of lesser mass are found farther
from the center.
The Crust
• SOLID layer of rock that forms Earth’s
outer skin, including the solid earth and
oceans.
The Crust
• Composition: mostly oxygen, silicon,
aluminum, (Granite and Basalt)
• Relative Temperature: Vary from air
temperature to 870 Co
• Density: 2.7 - 3.3g/cm3
• Thickness: (5-100 km) 100km
Crust
•Less than ___1___% of the
earth’s mass.
•Avg. thickness- 35
km
•5 to __100___ km thick
•2 kinds
•Temperature range is 0°C
to 1000°C
1. Continental
•Least dense layer
20-90 km thick;
contains older rock,
primarily granite
•Continental crust is
thicker than oceanic crust
2. Oceanic
5-10 km thick;
younger rock,
primarily basalt
•Oceanic crust is denser
than continental because
it’s made of denser
minerals
Crust Cont.
•All life exists in the
crust of the Earth.
•Approximately 90
different elements
are found in the
crust, but 5 make up
90% of the crust;
oxygen, silicon,
aluminum, iron, &
calcium
•Sodium, potassium,
& magnesium are
the most common
elements in the
remaining 10%
The Mantle
• SOLID layer of hot rock between
the crust and core.
The Mantle
• Composition: Mostly iron and magnesium
• Relative Temperature: 870oC – 3,700oC
• Density: 3.3 - 5.7 g/cm3
• Thickness: (100km – 3,000km) 2,900km
•67% of the earth’s mass
Mantle
•Much thicker than the crust
•Denser than the crust
because it’s made of denser
compounds
•contains 80% of Earth’s
volume
•Common elements found in
the mantle are: silicon,
oxygen, aluminum, iron, &
magnesium.
•The mantle consists of solid
rock, except for the
asthenosphere.
•Density increases in the
mantle as depth increases
Crust
Mantle
Lithosphere
Asthenosphere
Layers of the Mantle
The mantle is divided
into 3 sections.
1. Lithosphere- consists
of the uppermost part
of the mantle (rigid
rock) & the crust.
Average thickness is
100 km.
- Moho’s discontinuityboundary separating
crust from mantle;
discovered in 1909
using seismic data;
found approximately
30 km from Earth’s
surface
Layers of the Mantle cont.
2. Asthenosphere100-250 km deep;
more fluid layer, but
not liquid
3. Mesospherelowest layer; rigid
rock; 660-2900 km
deep
-temperature
increases with
depth, as does
density
Lithosphere
• The layer formed by the upper
part of the mantle and ALL the
crust.
• Averages 100 km thick
Asthenosphere
• Upper part of the Mantle.
• Molten (melted) rock layer.
• About 175 km thick.
• Plates float on it
The Core
• Center of the Earth; under
extreme pressure
The Outer Core
• Composition: LIQUID iron and nickel
• Relative Temperature: 3,700oC – 4,300oC
• Density: 9.9 – 12.2 g/cm3
• Thickness:(3,000km – 5,200km) 2,200km
Outer Core (liquid)
•Approximately
2200 km thick
•Liquid; very
dense molten
iron & nickel
•Believed to
create Earth’s
magnetic field;
similar to the
magnetic field
around a
magnet
The Inner Core
• Composition: SOLID iron and nickel
• Relative Temperature: 4,300oC – 7,200oC
• Density: 12.6 – 13.0 g/cm3
• Thickness: (5,200km – 6,428km)1,228km
Inner Core (solid)
•Densest layer because
it’s made of the
densest “stuff"
•Temperature is about
5000º Celsius
•Believed to be solid;
very dense iron &
nickel
•Remains solid due to
immense pressure
(may be 2 million times
stronger than normal
pressure exerted on
Earth’s surface);
molecules cannot
spread out & become
liquid
How does a hard boiled egg represent
the layers of the Earth?
Which parts can you name?
Which parts can you name?
• More challenging