UNIT 4: EARTH'S SYSTEMS AND RESOURCES

Convergent Boundaries

occuer when tectonic plates collide, one goes below the other.

• Continental-Contiental Boundaries: forms massive mountain ranges, like the Himalayas

• Oceanic-Continental/ Oceanic-Oceanic: one plate sinks beanth the other into the mantle ( a process called subduction )This melts rock and creates volcanoes and isalnd arcs, along with deep ocean trenches and severe earthquakes

Divergent Boundaries

occurs when plates pull apart, they both try to divereg away from one another. On this land, this creates rift vallets. In the ocean, magma rises to form new oceanic crust, causing sea floor spreading and mid-ocean ridges.

Transform Fault Boundaries

occurs when plates slide past each other horizontally, they move past eachother like walking away. Stress builds along a transform fault line until it suddenly slips, releasing energy as a powerful earthquake, like the San Andres Fault. Volcanoes do not typically form here.

Hotspots

plumes of magma rising from deep within the mantle can melt through the crust to form a chain of volcanic islands, like Hawaii, as the plate moves over it.

Soil Formation

soil forms as parent material, also known as bedrock, and undergoes mechanical or chemical weathering and is deposited over time. It develops distinct layers called soil horizons

O Horizon

organic layer made of freshly dead leaves, twigs, and decomposing matter

A Horizon

topsoil, rich in organic matter and nutrients , and critical for plant productivity

E Horizon

eluviation, also known as leaching layer. nutrients and minerals are washed downward by water

B Horizon

subsoil, amasses the clay, iron, and minerals leached from upper layers

C Horizon

partially broken-down parent material

Bedrock

the solid rock foundation beneath the soil

Soil texture

is determined by its exact percentage blend of sand, silt, and clay, which can be mapped out using a soil texture triangle.

Sand

the largest particles, with high permabality, meaning water draining throught the quickest, and a low water retention

Silt

a medium-sized particle with moderate drainage and retention

Clay

the smallest particles, with very tightly packed spaces, resulting in low permeability and high water-holding capacity. Clay particles carry a negative charge, giving soil a high cation exchange capacity to hold onto vital plant nutrients

Soil Degradation

soil can easily be eroded by wind or water. protecting ground cover with vegetation prevents erosion, preserves nurtrient levels, and helps with filter water to protect global water quality.

Atmosphere

consists of layers of gases wrapping around the Earth, divided into layers based on how temperature changes with altitude.

Exospehere

the outermost edge blending into space

Thermosphere

Blocks harmful X-Rays, which

Mesosphere

Startosphere

Troposephere