Landforms and Oceans

Natural Processes

Constructive Forces

Deposition

Products of Deposition

• sand dunes
• deltas
• shells on the beach

Destructive Forces

Weathering

• breaks down rocks at or near Earth's surface
• can be physical or chemical
• water, wind, ice, and temperature changes aid weathering
• plants cause weathering when roots break apart rock

Erosion

Earthquakes

• vibrations on Earth's surface
• caused by sudden movement in Earth
• often along a fault
• cause little or lots of damage
• can cause landslides or tsunamis

Both

• some processes are both constructive and destructive
• landslides
• volcanic eruptions
• floods

Landslides

• mass movement of land due to gravity
• can cause building to fall and gas lines to break
• can occur on the continental slope in the ocean

Volcanic Eruptions

• can change Earth's surface and weather patterns
• lava and ash can destroy forests and bury fields
• eruptions can build up mountains
• can occur under the oceans and creat seamounts

Floods

• when large amounts of water cover land that is usually dry
• floods cause rapid erosion
• floods leave behind new sediment and enrich the soil

Ocean Water Movement

Waves

• up and down movement of surface water
• most ocean waves are caused by wind
• waves move energy
• a wave changes shape when it reaches the shore

Currents

• flowing streams of water moving continually through the ocean
• some flow at the ocean's surface ;some are found deeper in the ocean
• currents flow along curved paths
• currents move warm and cold water to different reigons

Surface Currents

• caused by the movement of Earth
• caused by the force and direction of wind
• warm surface currents travel from the tropics to polar regions
• cold surface currents travel from polar regions to the tropics

Tides

• rise and fall of the level of ocean water
• caused by the moon's gravity on Earth
• tides rise and fall about twice a day
• at low tide the water level is at its lowest point
• at high tide the water level is at its highest point

Ocean Shore Zone

Beaches

• The shoreline, or coast, is the area where the land meets the ocean.
• Storms can cause wave action that removes sand from beaches.
• Shorelines are always changing because of wind and water.
• Wavs, currents, and tides affect beaches.

Barrier Islands

• islands with sandy beaches are called barrier islands
• naturally occurring and function to protect the mainland
• they change shape as waves deposit sand on the beaches
• currents can move sand from one end to the other

Estuaries

• the area where a river meets the ocean is an estuary
• they have a mixture of freshwater and saltwater
• waves can deposit sand in estuaries
• high tides bring in sediment and sea life

Inlets

• water filled spaces between barrier islands
• the amount of water in an inlet will change with tids
• ocean currents and storms can change the shape of an inlet opening

Ocean Floor

Continental Shelf

• the part of the continent located under the water
• the edges of the continents slope down from the shore into the ocean
• at the beach, you're on the continental shelf

Continental Slope

• steep slope where the continental shelf drops to the ocean floor
• depth of the ocean water increases greatly here

Trenches

• steep-sided canyons and deep, narrow valleys in the bottom of the ocean
• trenches are the deepest part of the ocean basin
• they are deeper than any valley found on land

Mid-Ocean Ridges

• divide the ocean floor into two parts
• a mountain range on the ocean floor
• under water volcanic mountains

Rift Zone

• narrow trench in the center of the highest part of the mid-ocean ridges
• volcanic activity that creates new ridges occurs at the rift zone

Human Activity

Pollution

• anything that harms the natural environment
• human activity causes pollution
• harm to Earth's air, water, or land

Conservation

• the wise use of natural resources
• reduce- use less of something
• reuse- use something over again
• recycle- make something new from an old product

Thanks