Four Cycles

Question 1

List the processes involved in the hydrologic cycle:

Answer 1

Evaporation
Precipitation
Run-off
Infiltration
Transpiration

Question 2

Name the two driving forces behind the water cycle.

Answer 2

Sun & gravity

Question 3

groundwater

Answer 3

water present beneath earth’s surface

Question 4

aquifer

Answer 4

a permeable layer of rock and sediment that contains groundwater

Question 5

water table

Answer 5

the uppermost level at which the water in a given area fully saturates rock or soil

Question 6

three significant anthropogenic interventions in the hydrologic cycle:

Answer 6

climate change, dams, agriculture

Question 7

Name the two largest sinks (storage areas) for carbon.

Answer 7

ocean & forests & soil

Question 8

Discuss how oceans play a major role in regulating CO2 levels in the troposphere.

Answer 8

Photoplankton in oceans take CO2 out of the air through photosynthesis

Through direct exchange, CO2 dissolves in and out of surface ocean water.

Question 9

Carbon sink

Answer 9

A carbon reservoir that stores more carbon than it releases

Question 10

Describe the two major anthropogenic interventions in the carbon cycle:

Answer 10

Extraction & Combustion of fossil fuels

Deforestation

Question 11

What 2 organic compounds is nitrogen found in?

Answer 11

Ammonia & Nitrate

Question 12

Identify the two major ways that nitrogen is “fixed”:

Answer 12

Through Synthetic Fixation and Bacterial Fixation

Question 13

Synthetic Fixation

Answer 13

Humans combust fossil fuels to convert Nitrogen into Nitrate

Question 14

Bacterial Fixation

Answer 14

Rhizobacteria converts nitrogen into ammonia

Question 15

Nitrogen Fixation

Answer 15

Nitrogen in the atmosphere is changed into a form that plants can absorb through their roots. Bacteria, such as the rhizobacteria, that live in the soil converts the nitrogen into ammonia. Nitrogen can also be fixed when lightning provides the energy needed for N2 to react with oxygen, producing nitrogen oxide, NO, and nitrogen dioxide, NO2.

Question 16

Nitrification

Answer 16

the conversion of ammonia into nitrite (NO2-) and then into nitrate (NO3-) by soil bacteria

Question 17

Assimilation

Answer 17

The process by which producers incorporate elements into their tissues.

Question 18

Ammonification

Answer 18

the process by which fungal and bacterial decomposers break down the organic nitrogen found in dead bodies and waste products and convert it into inorganic ammonium

Question 19

Denitrification

Answer 19

The conversion of soil nitrogen into nitrous oxide gas which returns to atmosphere

Question 20

Describe two anthropogenic interventions in the nitrogen cycle

Answer 20

Leaching & Eutrophication - synthetic fertilizer nitrates leach out of soil and into water ways that cause algae blooms

Ammonia volatilization - excess fertilizer leads to ammonia gas entering atmosphere (acid rain)

Question 21

Explain why phosphorus does not circulate in the troposphere to a great extent:

Answer 21

Phosphorus does not circulate in the troposphere because there is no gas phase where phosphorus enters the atmosphere.

Question 22

Identify the largest sinks for phosphorus:

Answer 22

Rocks and Sediments

Question 23

Phosphorus is typically found in what ionic form?

Answer 23

PO4-3

Question 24

Explain why the addition of phosphate compounds to aquatic areas typically has a dramatic effect on biological productivity.

Answer 24

The addition of phosphate compounds leads to aquatic areas going through eutrophication which creates an algae bloom, blocking the sun from other vegetation. This also causes lower oxygen levels so more animals result dead.

Question 25

Describe how human activities have influenced the phosphorus cycle

Answer 25

Using synthetic fertilizers has led to more phosphorus draining unto bodies of water