How do physical processes shape Earth’s surface? THE PHYSICAL WORLD.

How do physical processes shape Earth’s surface?

THE PHYSICAL WORLD

PLANET EARTH

OUR SOLAR SYSTEM• Sun at the center

• 8 known planets

• Mercury, Venus, Earth, Mars (inner planets)

• Jupiter, Saturn, Uranus, and Neptune (outer planets)

• Jupiter is largest

• Pluto is a dwarf planet---too small; not enough gravitational pull

SOLAR SYSTEM CONTINUED• Inner planets are terrestrial

planets---have solid, rocky crusts

• Only Earth has temps to support life

• Outer planets are gas giant planets---gaseous and less dense

• Asteroid belt btwn Mars and Jupiter

EARTH• Circumference of 24,900 miles

• 70% of surface is water---all water on Earth makes up the HYDROSPHERE

• 30% is land---LITHOSPHERE

• Air we breathe makes up the ATMOSPHERE(78% nitrogen, 21% oxygen, argon, others)

• All life makes up the BIOSPHERE

LANDFORMS• Natural features of Earth’s surface

• Largest are the continents

• CONTINENTAL SHELF: part of a continent that extends out underneath the ocean

• Lowest point on Earth’s crust: Mariana Trench (36,198 feet)

• Highest point: Mt. Everest (29,029 feet)

FORCES OF CHANGEHow is Earth’s structure related to the creation of continents,

oceans, and mountain ranges?

EARTH’S STRUCTURE• 3 main layers:

• 1. CORE: innermost layer; super-hot, solid inner core; super-hot liquid outer core (mostly nickel and iron)

• 2. MANTLE: middle layer; dense hot rock that is flexible

• 3. CRUST: outer layer; hard, rocky shell---broken into tectonic plates

CONTINENTAL DRIFT• Theory that the continents were

once joined and then slowly drifted apart

• Supercontinent was called Pangaea

PLATE TECTONICS• Def: activities of continental drift

and magma flow, which create many of Earth’s physical features

• MAGMA: molten rock (below surface)

• Belief is that this has been happening for 2.5-4 billion years

• Don’t know exactly what causes it

INTERNAL FORCES OF CHANGEHow does plate tectonics affect Earth’s surface?

COLLIDING PLATES• SUBDUCTION: process by which

oceanic plates dive beneath continental plates, often causing mountains to form on land

• ACCRETION: slow process in which an oceanic plate slides under a continental plate, creating debris that can cause a continent to grow

• Called convergent boundaries

SPREADING PLATES• SPREADING: process by which

magma wells up btwn oceanic plates and pushes them apart

• Called divergent boundaries

• Creates rifts

• Mid-Atlantic Ridge

FOLDS AND FAULTS• FOLD: a bend in layers of rock,

sometimes caused by plate movement

• FAULT: a crack or break in Earth’s crust

• FAULTING: process of cracking that occurs when the folded land cannot be bent any further

EARTHQUAKES• Sudden, violent movements of the

lithosphere along fault lines

• Caused by built up tension btwn plates

• Measured by the Richter Scale

VOLCANOES• Mountains formed by lava or

magma that breaks through the Earth’s crust

EXTERNAL FORCES OF CHANGE

WEATHERING • Def: chemical or physical

processes that break down rocks into smaller pieces

• Physical weathering involves physically breaking down rocks into smaller pieces

• Chemical weathering changes the chemical makeup of rocks

EROSION• Def: the movement of weathered

rock and material by wind, glaciers, and moving water

• GLACIER: large body of ice that moves across the surface of the Earth

• MORAINE: piles of rocky debris left by melting glaciers

SOIL BUILDUP• Five factors of soil formation

• 1. Climate: wind, temp, and rainfall determine type of soil

• 2. Topography: affects flow or runoff water

• 3. Geology: determines parent material

• 4. Biology: adds organic matter to soil

• 5. Time

EARTH’S WATERWhat drives the water cycle?

THE WATER CYCLE• Def: regular movement of Earth’s

water from ocean to air to ground and back to the ocean

• Total amount of water on Earth does not change

• Sun drives the cycle by evaporation…

EVAPORATION• Def: the changing of liquid water

into vapor

• Water vapor is gathered in the air

• Warm air holds vapor better than cool air

• Air cools, water condenses…

CONDENSATION• Def: process of excess water vapor

changing into liquid water when warm air cools

• Tiny droplets form together to create clouds

• When they get too full, they release the water

PRECIPITATION• Def: moisture that falls to Earth as

rain, sleet, hail, or snow

• Precipitation sinks into the ground

• Collects in streams and lakes

• Gets returned to oceans

• Hakuna matata!

BODIES OF SALT WATER• 70% of Earth is water

• 97% of that is one continuous body of water

• Divided into 5 oceans:

• 1. Pacific

• 2. Atlantic

• 3. Indian

• 4. Arctic

• 5. Southern

DESALINATION• Def: the removal of salt from

seawater to make it usable for drinking and farming

• Expensive process

BODIES OF FRESH WATER• 3% Earth’s water is freshwater

• 2/3 is trapped in glaciers and ice caps

• GROUNDWATER: water located underground; supplies wells and springs

• AQUIFER: underground water-bearing layers of porous rock, sand, and gravel