Groundwater, Fossil Fuels, and Carbon Cycle: Key Concepts for Environmental Science

Resource & Sustainability Framework

Understanding long-term availability, recharge vs. withdrawal, and human impact.

Groundwater

Water stored underground in pore spaces of soil, sediment, and rock

Porosity

Percentage of rock/sediment that consists of open space.

Permeability

Ability of a material to allow fluids to pass through

Water Table

Boundary between unsaturated zone (vadose) and saturated zone

Recharge

Addition of water to the groundwater system

Discharge

Removal of groundwater

Springs

Human-made holes that access groundwater

Using Groundwater

Requires pumping, stable aquifers, and understanding recharge rates

Consequences of Overuse

Lowering of the water table, cone of depression, land subsidence, saltwater intrusion.

Energy Sources

Solar, geothermal, fossil fuels, nuclear, hydroelectric, wind.

Formation of Fossil Fuels

Burial, heating, and chemical alteration of organic matter.

4 components that conventional oil and gas reservoirs need

1) Source rock 2) Reservoir rock 3) Seal rock 4) Trap

Nonrenewable resource

________ - nature takes a long time to replace it (centuries to millions of years).

Renewable Resource

_______ - nature can place it in a short time (relative to the human lifespan, months to decades).

Shale Gas

Gas trapped in shale; extracted via horizontal drilling + hydrofracturing.

Hydrofracturing (Fracking)

Pumping fluids into shale to increase permeability.

Coal

Solid fossil fuel formed from buried plant material in anoxic swamps.

Trap

Arrangement of rocks that keeps the oil and gas in a confined area

Source Rock

Shale rich with decayed organic matter

Seal Rock

Rock with low porosity and low permeability (like a shale)

Reservoir Rock

Rock with high porosity and high permeability (like a sandstone)

Metal Sources

Volcanoes, hydrothermal fluids, ore minerals.

Primary Deposits

Form directly from magmatic or hydrothermal processes.

Secondary Enrichment

Surface processes that concentrate metals (weathering, groundwater movement).

Photosynthesis

A process that moves carbon from the atmosphere reservoir to the life reservoir

Respiration

A process that moves carbon from the life reservoir to the atmosphere reservoir

Volcanism

A process that moves carbon from the solid earth reservoir to the atmosphere reservoir

Burial of organic material

A process that moves carbon from the life reservoir to the solid sphere reservoir

The formation of biochemical limestone

A process that moves carbon from the ocean reservoir to the solid earth reservoir.

The burning of fossil fuels

A process that moves carbon from the solid earth reservoir to the atmosphere reservoir.