Science- The Earth's Layers

Dynamic planet

Term describes the constantly changing nature of Earth due to internal and external forces

Compostional and Mechanical

What are the two layers of the Earth

Crust, Mantle, Inner Core, Outer Core

Compositional Layers of the Earth

Crust

Compositional layer that is the outermost, thinnest layer of the earth

Continental

Type of crust that is thick, less dense, and made of granite?

Oceanic Crust

Type of crust that is thin, dense and made of basalt?

Mantle

Extends from the base of the crust, composed of sillicate rocks and is the largest layer by volume

Outer Core

Creates the Earth’s magnetic field, liquid, and composed out of liquid iron and nickel

Inner Core

Solid due to the immense pressure despite extreme heat, and made out of solid irond and nickel

Mechanical Layers of the Earth

Litosphere, Asthenosphere, Mesosphere, Outer Core, Inner Core

Litosphere

The outermost mechanical layer, consists of the crust, and the uppermost part of the mantle

Asthenosphere

Located beneath the litosphere, soft ductile layer of the upper mantle

Mesosphere

Lower mantle, located beneath the litosphere, characterized by high pressure and temperature

Pacific Ring of Fire

Horeshoe-shaped zone around the Pacific Ocean, 75% of the earth’s active volcanoes, and 90% of the world’s earthquakes are located here

Plate Boundaries

Edges where two or more tectonic plates meet, zones of intense geoglogical activity

Fault (fracture line), Epicenter (surface point above focus), Focus/Hypocenter (underground origin) Seismic waves

Parts of an Earthquake

Body Waves, Surface Waves

Two types of Seismic Waves

Body Waves

Travel through the Earth’s interior

Surface Waves

Travel along the Earth’s surface, are more destructive during eathquakes

P-Waves (Primary Waves), S-waves (Secondary waves)

Types of Body Waves

P-Waves (Primary Waves)

These are the fastest seismic waves and can travel through solids, liquids, and gases.

S-waves (Secondary Waves):

Are slower than P-waves and can only travel through solids. They cause particles to move perpendicular to the direction of wave propagation, resulting in a shearing motion.

Love Waves, Rayleigh waves

Types of Surface Waves

Love Waves

Causes a horizontal motion, faster than Rayleigh waves, named after A.E.H. Love or Augustus Edward Hough Love

Rayleigh Waves

Create an elliptical motion, the most damaging type of seismic wave, named after Lord Rayleigh (John William Strutt)

Seismograph

Instrument that records earthquake waves

Seismogram

Traces of amplified, electronically recorded ground motion made by seismographs