Last in class quiz Tues 4/25
Which of the following processes occurs first in the formation of fossil fuels?
• Burial under low o2 conditions
• it depends on the type of fossil fuel
After, you have accumulation of remains that undergo burial in low to no oxygen conditions,
Energy - Geothermal and Nuclear
Geothermal heat is ubiquitous, and driven mainly by radioactive decay.
◦ Hot geothermal
◦ Cold-heat pump
• source for our energy is hydrothermal circulation
Uranium, the main fuel of nuclear energy, is mined like placer gold as pitchblende (UO2) and by
• ore created by initial process that gets taken away by stream and then is concentrated bc
of higher density
• system: fuel source, that generates steam which fuels turbine, then water is cooled in
cooling towers and returned back into the system (circulation)
Water Conversions - Groundwater
A porous and permeable rock unit that transports water is known as ______.
• sandstone unit
A sedimentary or rock unit that does not transmit water easily is known as ____.
• sandstone unit
Groundwater wells are the most widespread water supply.
◦ Water table
Groundwater mining is unsustainable
• Ogallala Aquifer
◦ unconfined aquifer
◦ rate at which we extract far exceeds rate of recharge • contaminants can also affect groundwater
Water Conversions - Surface Water
Rivers have been dramatically transformed by dams, canals, levees, dikes, dredging, irrigation
• Three Gorges Dam, China
◦ has created reservoir that has displaced large # of people in villages
◦ modifies landscape & course of river over time
◦ allows them to slowly release floodwater instead of all at once
• levees interfere with natural flood processes of river
◦ water that may have just spilled out on floodplain and carried downstream where
it can carry much larger flood
• dredge (taking material out) to keep river at appropriate depth
Artificial levees defeat purpose
• rainwater falls across impermeable surface -