3. Chemically, it can be
divided into
•Crust
•Mantle ( Upper and Lower)
•Core (Outer and Inner)
4.
5. • Connard Discontinuity
Zone that separates the Earth’s upper crust from the
lower crust.
• Mohorovicic Discontinuity - Zone that separates the Earth’s
crust from the asthenosphere.
• Repetti Discontinuity
Zone that separates the upper mantle from the lower mantle.
• Gutenberg Discontinuity
Zone separating the lower mantle from the core; it is
located at a depth of about 1,800 mi.
• Lehman Discontinuity Zone that separates the Earth's
outer core from the Inner core
Discontinuities in Earth Structure
11. • Thinnest layer of the Earth that ranges from
only 2 miles in some areas of the ocean
floor to 75 miles deep under mountains
• Made up of large amounts of silicon and
aluminum
• Two types of crust: oceanic crust and
continental crust
• Composed of plates on which the continents
and oceans rest
CRUST
12. • 7 – 10 km. thick
• Found under
ocean floor
• Made of dense
rocks (basalt)
Ocean Land
Crust
• Made up of
Si,O,Al,Ca,Na and K
• 35 -40 km thick
• Found under land
masses
• Less dense rocks
(granite)
13. • 7 – 10 km. thick
• Found under
ocean floor
• Made of dense
rocks (basalt)
Ocean Land
Crust
• Made up of
Si,O,Al,Ca,Na and K
• 35 -40 km thick
• Found under land
masses
• Less dense rocks
(granite)
15. • Solid but capable of flowing (like hot asphalt or fudge)
• Thickest layer of the Earth (making up 70% of the
Earth’s mass)
• The hot material (magma) in the mantle rises to the
top of the mantle, cools, then sinks, reheats, and
rises again. These convection currents cause
changes in the Earth’s surface
Upper Mantle
Convection
Currents
Middle
Mantle
Lower Mantle
Mantle
20. Outer
Core
• Molten (liquid) metal that is about
4,700°C (8,500°F)
• Located about 1,800 miles beneath the
crust and is about 1,400 miles thick
• Composed of the melted metals nickel
and iron
21. How did scientists come to know
that the outer core is liquid?
-Iron
- Nickel
22. Inner Core
• Solid sphere composed mostly of iron
• It is believed to be as hot as 6,650°C (12,000°F)
• Heat in the core is probably generated by the
radioactive decay of uranium and other elements
• It is solid because of the pressure from the outer
core, mantle, and crust compressing it
tremendously
The structure of Earth can be defined in two ways: mechanically or chemically…but we will focus on the chemical properties of the Earth’s interior…
The earth’s layer is divided by a zone known as discontinuity…Discontinuities in earth structure
Connard Discontinuity - Zone that separates the Earth’s upper crust from the lower crust.
Mohorovicic Discontinuity - Zone that separates the Earth’s crust from the asthenosphere.
Repetti Discontinuity -Zone that separates the upper mantle from the lower mantle.
Gutenberg Discontinuity - Zone separating the lower mantle from the core; it is located at a depth of about 1,800 mi.
Lehman Discontinuity- Zone that separates the Earth's outer core from the Inner core
Connard Discontinuity - Zone that separates the Earth’s upper crust from the lower crust.
In 1909, Yugoslavian seismologist andrija Mohorovicic found out that the velocity of seismic waves changes and increases at a distance of about 50km below the Earth’s surface…This lead to the idea that there is a difference in density between the Earth’s outermost layer (crust) and the layer that lies below it (mantle)..The boundary between these two layers is called Mohorovicic discontiuityin honor of Mohorovicic and is short termed Moho…
Mohorovicic Discontinuity - Zone that separates the Earth’s crust from the asthenosphere.
- Underneath some mountains the crusts thickness extends to 72 km
Underneath some mountains the crusts thickness extends to 72 km
What is the most abundant element in the Earth’s crust? OXYGEN – 46.60%
Convection Currents – current in the mantle because of the heat from the inner layers of the earth…and is the force that drives the plates to move around…
The attempt to study the Earth’s mantle extended as far as studying the rocks from volcanoes, simply because they were found in the mantle…but scientist also studies rocks from the ocean floor… WHAT ELEMENTS MAKES UP THE MANTLE?
Inner part of the MANTLE consists of more Iron…This explains why lower mantle is denser than the upper portion…
TEMPERATURE AND PRESSURE INCREASES AS IT DEEPENS… High temp and pressure allows the solid rocks to flow slowly…
Mohorovicic Discontinuity - Zone that separates the Earth’s crust from the asthenosphere.
- crust and the uppermost layer of the mantle is relatively cool, outermost rigid shell known as LITHOSPHERE about 50 to 100 km. thick… beneath the lithosphere lies the soft. Weak layer known as ASTHENOSPHERE, made of hot molten material… (temp – 300 to 800 degree C)
Has 2 layers (OUTER and INNER)…2900 km thick below the earth’s surface…made up of Nickel and Iron…
What tells us that the inner core is made up of iron?
Earth’s magnetic field strengthens the idea that the Earth’s outer core is molten or liquid… OUTER CORE is made up of Iron and Nickel moving around the solid inner core creating Earth’s MAGNETISM… What is the use of the magnetic field in the outer core?...MAGNETIC FIELD GENERATED IN THE OUTER CORE PROTECTS US FROM THE SOLAR WINDS, COSMIC RADIATION OR HIGH ENERGY PARTICLES EMITTED BY THE SUN…IT ALSO PROVIDES THE BASIS FOR NAVIGATION WITH A COMPASS…
Q : Is the inner core solid, liquid or gas? What keeps it in this phase?
What do these two images tell us about the layers of the Earth?
