3.8 – 3.10

Important Fuels  coal  formed from decayed plants and animals  fossil fuel  fuels formed from the fossils of plants or animals  good for generating electricity

EIA Sept Report

There are 4 major types of coal 1. Anthracite  Hard, shiny, and black coal  Anthracite is the most expensive type of coal to mine  Least common type  Because it burns slowly and cleanly, it was once a preferred way to heat homes

2. Bituminous  This coal is soft, black and shiny  It is the most common type of coal  Bituminous coal is called soft coal  Coal tar is found in bituminous coal  This sticky substance may be used to make plastics, detergents, perfumes

3.Sub-bituminous coal  Soft, crumbly, dull in color, black  It is the second most common type of coal 4.Lignite is also known as brown coal  It is poor in quality  When burned, lignite gives off an offensive odor and produces large amounts of black sooty smoke

 Coal is often found in layers called beds or seams, and there are two methods of mining  Surface mining  Removing layers of the earth to expose things below the surface  About 2/3 of the coal is mined in this manner  Overburden Layers of rock and soil that must be removed for surface mining  Underground mining  Large vertical shafts are dug to the coal bed

 Petroleum is another fossil fuel  Petroleum means “Rock oil”  Crude oil is petroleum in its natural state when it is first pumped out of the ground  Petroleum is a mixture of hydrocarbons  Petroleum is used to make many things ranging from rubber tires to imitation leather

 Petroleum is found in sedimentary rock that is porous  It is usually just pumped out of the ground through a tiny shaft  goes through a process called fractional distillation  fractions  Different groups of petroleum (hydrocarbons)

Caves  any hollow space in the earth’s crust that has formed naturally and is large enough for a person to enter  caverns  large caves  speleology  scientific study of caves  spelunking  exploring a cave

 kinds of caves  sea cave  created by waves beating against a cliff creating caves  lava cave  a cave left after the eruption of a volcano  solution caves  usually form in sedimentary rock or limestone because of rock being dissolved by water  the walls of the caves usually contain a mineral called calcium carbonate

Sea Cave Sea Cave Lava cave Solution cave Solution cave

 cave formations  stalactites  icicle shaped structure that hangs from the ceiling of a cave  formed from the minerals that settle out of water passing through the ground into a cave  soda straw  long thin hollow structures that resemble straws hanging from the ceiling

Soda straws Soda straws Stalactites Stalactites

 stalagmite  when the water drips from the ceiling and reaches the floor dissolved minerals will form a cone coming up from the floor of the cave  column  forms when a stalactite and stalagmite form together

StalagmiteColumn

 Flowstone  Flowstone is a cave formation formed by water flowing over a broad area of a cave  It may look much like a frozen waterfall Draperies  Draperies are a formation formed by water running down an angled ceiling  They are thin sheets of hanging rock

A Giant Magnet More than 400 years ago, William Gilbert discovered the earth is a giant magnet  magnetism  force that pulls magnets together or pushes them apart  magnetic field  area surrounding a magnet in which the force of magnetism affects other objects  The earth’s magnetic field stretches tens of thousands of kilometers into space

 magnetic poles  Poles are located at the ends of the magnets  north and south poles are located on every magnet no matter the length or the number of times it is split  magnetic north and geographic north poles are not in the same place

 source of earth’s magnetism  originate in the outer core  believed to be produced by electric fields and not a solid stone type magnet  electromagnet  a magnet that is produced by an electric current flowing through an object

 magnetosphere  region in space around the earth that is affected by the earth’s magnetic field  It blocks potentially harmful solar winds from slamming into the earth  Solar winds are particles that constantly stream from the sun’s surface  auroras  solar wind particles that collide with air molecules and create a beautiful light display over the poles

 Magnetosphere and solar wind solar windAurora

 aurora borealis  Is commonly called the “Northern Lights”  Aurora located over the north pole  aurora australis  Commonly called “Southern Lights”  Aurora located over the south pole