Environmental Systems
What are the four major Earth systems (spheres)?
Atmosphere, hydrosphere, geosphere, and biosphere
What type of plate boundary occurs where two plates move away from each other?
Divergent boundary
What is the difference between renewable and nonrenewable natural resources?
Renewable resources can be replenished on human-relevant timescales if managed appropriately; nonrenewable resources form or replenish far more slowly than they are consumed.
What is the name of the upper mineral soil horizon that usually contains substantial organic matter?
A horizon, or topsoil
What is a watershed?
An area of land where water drains toward a common outlet.
What is the difference between a reservoir and a flow in an environmental system?
A reservoir stores matter or energy; a flow transfers it between parts of a system
What type of plate boundary is associated with plates sliding past one another?
Transform boundary
Which extraction method typically removes large quantities of overlying rock and soil to reach a shallow mineral deposit?
Surface mining, such as open-pit mining
What are the three major mineral particle-size groups used to describe soil texture?
Sand, silt, and clay
What is the water table?
The upper surface of the saturated zone in an unconfined groundwater system.
Why is solar energy described as flowing through ecosystems while carbon is described as cycling?
Energy enters, transfers, and eventually disperses as heat; carbon atoms are recycled between reservoirs
What geological process occurs when a denser oceanic plate sinks beneath another tectonic plate?
Subduction
What extraction method is commonly used to obtain stone such as limestone or granite for construction?
Quarrying
Which soil particle type is smallest and tends to retain more water while allowing slower drainage?
Clay
What is the difference between porosity and permeability?
Porosity is the amount of open space in a material; permeability describes how readily water can move through connected spaces.
A wildfire removes vegetation, increasing erosion and sediment entering streams. Identify three Earth systems interacting in this example.
Biosphere (vegetation), geosphere (soil), and hydrosphere (streams); atmosphere may also be involved
Why do continental–continental collisions generally produce large mountain ranges rather than volcanic arcs?
Continental crust resists deep subduction, causing crust to compress, thicken, and uplift.
Why might underground mining be chosen instead of surface mining, and what is one major tradeoff?
It can access deeper deposits with less extensive surface excavation, but may involve higher costs, subsidence, or greater worker safety risks.
How does compacting soil generally affect infiltration and surface runoff?
Compaction reduces connected pore space and typically lowers infiltration, increasing runoff.
After several weeks of little precipitation, the water table falls. What happens to the saturated and unsaturated zones?
The saturated zone becomes lower or thinner, while the unsaturated zone generally extends deeper.
As Arctic ice melts, darker ocean water absorbs more solar energy, causing additional warming and ice melt. What type of feedback is this, and why?
Positive feedback, because the initial change causes the change to happen once again
A region has a deep-ocean trench, powerful earthquakes, and a chain of volcanoes on a nearby continent. What boundary type is present, and what causes the volcanoes?
Oceanic–continental convergent boundary; fluids released by the subducting slab promote melting in the overlying mantle
A shale formation contains natural gas that cannot easily flow into a conventional well. What technique may be used to increase gas flow, and identify two environmental concerns.
Hydraulic fracturing; concerns include water use, wastewater management, methane leakage, and potential water contamination
A steep hillside loses its vegetation during construction. Explain two ways this could affect the soil during heavy rain.
Increased erosion and loss of topsoil; greater surface runoff and sediment transport into nearby waterways
A fertilizer spill occurs on permeable gravel above an aquifer. Explain how the pollutant could reach a drinking-water well and identify one way to reduce the risk.
Water can carry dissolved fertilizer downward through connected pore spaces into groundwater, which may move toward a well. Prevention includes reducing spills, managing fertilizer application, or protecting well recharge areas.