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. MASS, DENSITY, AND ESCAPE VELOCITY The Earth's mass is about 5.98 x 1024 kg. The Earth has an average density of 5520 kg/m3 (water has a density of 1027 kg/m3). Earth is the densest planet in our Solar System. To escape the Earth's gravitational pull, an object must reach a velocity of 24,840 miles per hour (11,180 m/sec).

The Composition of the Earth The Earth is made of many different and distinct layers. The deeper layers are composed of heavier materials; they are hotter, denser and under much greater pressure than the outer layers.

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 The Earth is made of many different and distinct layers. The deeper layers are composed of heavier materials; they are hotter, denser and under much greater pressure than the outer layers. Core: The Earth has a iron-nickel core that is about 2,100 miles in radius. The inner core may have a temperature up to about 13,000°F (7,200°C = 7,500 K), which is hotter than the surface of the Sun. The inner core (which has a radius of about 750 miles (1,228 km) is solid. The outer core is in a liquid state and is about 1,400 miles (2,260 km) thick. 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 The Earth is made of many different and distinct layers. The deeper layers are composed of heavier materials; they are hotter, denser and under much greater pressure than the outer layers. Core: The Earth has a iron-nickel core that is about 2,100 miles in radius. The inner core may have a temperature up to about 13,000°F (7,200°C = 7,500 K), which is hotter than the surface of the Sun. The inner core (which has a radius of about 750 miles (1,228 km) is solid. The outer core is in a liquid state and is about 1,400 miles (2,260 km) thick.

The Structure of the Earth Lithosphere Solid Asthenosphere Viscous Liquid The Structure of the Earth Outer Core Liquid Mesosphere Solid Core: The Earth has a iron-nickel core that is about 2,100 miles in radius. The inner core may have a temperature up to about 13,000°F (7,200°C = 7,500 K), which is hotter than the surface of the Sun. The inner core (which has a radius of about 750 miles (1,228 km) is solid. The outer core is in a liquid state and is about 1,400 miles (2,260 km) thick. Inner Core Solid

Lithosphere = ‘rock sphere’ Crust and upper rigid part of Mantle Asthenosphere = ‘weak sphere’ Lower 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)