Unit 1: Earth's Systems

What are the 4 earth systems?

lithosphere/geosphere, hydrosphere, atmosphere, biosphere

Lithosphere

solid earth

Hydrosphere

all water

Atmosphere

gases/the air

Biosphere

all life

Layers of the Geopsphere

crust, mantle, core

Crust

thin, cool, rocky outer “skin”

Mantle

hot and mostly solid; makes up bulk of earth

Core

outer is molten metal, inner is solid metal

What are the crust and mantle divided into?

lithosphere, asthenosphere, and lower rock

What moves the tectonic plates?

convection currents in the asthenosphere

What happens when plates collide or separate?

landforms form

How are global distributions of plate boundaries used?

to determine the location of volcanoes and island arcs

Convergent Boundaries

when one tectonic plate slides under another; earthquakes, volcanoes, island arcs, ocean trenches, mountains

Divergent Boundaries

when two plates pull apart from eachother; seafloor spreading and rifts

Transforming Boundaries

when two plates slide against eachother; earthquakes and no volcanic activity

Island Arcs

chains of active volcanoes; Ex. ring of fire

Hotspots

locations beneath the tectonic plates; not associated with boundary interactions

What are the 4 distinct parts of soil?

mineral Particles (45%), organic matter, water, air

Soil Weathering

the breaking down of rock

Soil Erosion

the movement of sediment from broken rock

Soil Deposition

the dropping of sediment in a new place

What are the 3 types of weathering

physical, chemical, biological

How does native vegetation prevent excessive erosion?

due to significant root system it firmly holds in the soil

Watershed

an area of land that feeds all the water running under it, draining off into a body of water; Louisiana is the hub for north america

Why is soil usually more fertile in lower planes?

What determines how fast the erosion will occur?

the slope; the steeper the faster

Formation of Soil Factors

Parent Material

Climate

Topography

Organisms

Time

Parent Material

rock material from which soil is derived

Climate

slower in colder climates because of reduced decomposition

Topography

surface slope and arrangement of landscape

Organisms

recyclers of organic material

Time

older soils with lots of vegetation history most fertile

O Horizon

surface litter; fallen leaves, organism detritus, humus

A Horizon

topsoil; where plants grow; zone of biological activity, holds water and nutrients

E Horizon

zone of leaching; dissolved materials moving downwards, not always present

B Horizon

subsoil; larger rock particles mixed with inorganic and organic materials, accumulation of leached minerals, almost no organic matter

C Horizon

rock that underwent weathering

R Horizon

bedrock; soild rock layer. usually sandstone, limestone, or granite

Desert

hot, dry climate. Sand and weak humus mineral mixture

Glasslands

semiard climate. Clay calcium compounds

Tropical Rainforest

humid, tropical climate. Iron and aluminum compunds and clay

Deciduous Forest

humid, mid climate. Humus mineral texture

Coniferous Forest

humid, cold climate. Humus and iron aluminum compounds

What climate type does Louisiana have?

Deciduous Forest

What are the two main physical properties of soil?

soil color and texture

Soil Color

composition and fertility

Soil Texture

determined by size

What does dark soil indicate?

fertile soil

What are the 3 types of soil texture particles?

clay, silt, and sand

Loam

soild with an even mixture of clay, silt, and sand

How do you determine soil texture type?

by the size of the particles

Porosity

the ability of soil to hold water

Permeability

how easy can water flow through

Soil PH

a main chemical property of soil; measures the hydrogen ion concentration

Cation Exchange

process that allows plants to gain nutrients

Cation Exchange Capactiy

a soil’s ability to hold cations, preventing them from leaching, increasing their avalibility to plants

What makes up over 80% of soil?

bacteria, fungai, and protists

What microorganisms break down large organic material?

earthworms and rodents

Humus

organic part of soil