Presentation on theme: "Introduction to Planet Earth Let’s dig a hole to China!"— Presentation transcript:
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). Earth is made of several layers with different compositions and physical properties, like temperature, density, and the ability to flow.
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 Core Solid Outer Core Liquid Mesosphere Solid Asthenosphere Viscous Liquid Lithosphere Solid
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°C Sun 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)