introduction to planet earth
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Introduction to Planet Earth. Let’s dig a hole to China!. Earth Stats. The Earth 's mass is about 5.98 x 10 24 kg. Earth is the densest planet in our Solar System (mass/volume). - PowerPoint PPT PresentationTRANSCRIPT
Introduction to Planet Earth
Let’s dig a hole to China!
Earth Stats
• The Earth's mass is about 5.98 x 1024 kg.
• Earth is the densest planet in our Solar System (mass/volume).
• Earth is made of several layers with different compositions and physical properties, like temperature, density, and the ability to flow.
The Composition of the Earth
The Composition of the Earth
Crust• Thinnest layer (5-100 km)• Two types of crust
• Continental • Like granite• Average 30 km
• Oceanic• Like basalt
(Basalt is denser than granite!)• Average 5-8 km
The Composition of the Earth
Mantle• Extremely Thick! (2,900 km)• It is too far down to drill
• How do we know what it is made of?
• Scientists infer based on:• Pushed up rock• Ocean floor/molten rock
• What is it like?• Like the mineral olivine
• Large amounts of iron and magnesium
www.soc.soton.ac.uk
The Composition of the Earth
Core• Pretty darn big. (6,856 km)
• (Slightly bigger than Mars!)• 33% mass of the Earth
• Scientists think….• Made mostly of iron• Some nickel, sulfur, oxygen
• What is the evidence?• The particular way seismic
waves travel• Earth’s Magnetic field
N
S
The Structure
of the Earth
Inner CoreSolid
Outer CoreLiquid
MesosphereSolid
AsthenosphereViscous Liquid
LithosphereSolid
Asthenosphere = ‘weak sphere’Lower part of Mantle
Lithosphere = ‘rock sphere’Crust and upper rigid part of Mantle
How HOT is it?
Surface of Sun! 5,500°CSun Core 15,000,000°C
Convection• Convection (heat) currents
– carry heat from the hot inner mantle to the cooler outer mantle.
• The mantle gets warmer with depth • top of the mantle is ~ 1,600° F (870° C)• bottom of the mantle is ~4,000-6,700° F
(2,200-3,700° C) • The mantle contains most of the mass of
the Earth
Let’s Make Models of the Earth!
• Inner Core (yellow) diameter 2 cm (4)• Outer core (orange) diameter 6 cm (4)• Mesosphere (red) diameter 11cm (4)• Asthenosphere (brown) diameter 12cm (2)• Lithosphere (sand)
– -after assembly roll edges of asthenosphere in glue and then sand (1.5mM thick)