Download Yr 11 ENV Web Quest

DP5 – Describe forms in which carbon is now ‘locked up’ in the lithosphere and biosphere
The atmosphere of the early Earth was dominated by carbon dioxide. An important step in the evolution of
the atmosphere was the removal of much of this carbon dioxide
Using the following website, complete the following answers
http://www.physicalgeography.net/fundamentals/9r.html
http://www.oregonwild.org/oregon_forests/old_growth_protection/forests-global-warming/globalwarming-report/part-ii-how-does-carbon-move-in-and-out-of-the-atmosphere
a) Identify one form in which carbon is now ‘locked up’ so that it cannot be directly returned to the
atmosphere
b) Describe how this carbon is ‘locked up’ in this form
Using the images below and the website listed above complete table 1 which describes forms in which
carbon has become ‘locked up’ in the lithosphere and biosphere.
Table 1. Stores of Carbon in the Lithosphere and Biosphere
Location
Lithosphere
Form
Inorganic
Organic
Biosphere
Terrestrial organisms
Oceanic organisms
Description and Percentage
DP9 - Process and present information from secondary sources to list and describe the forms in
which carbon is now ‘locked up’ in the lithosphere and biosphere
Examine the information contained in the table below and use this information to answer the
following questions
Table 2. Estimated major stores of carbon on the Earth
Sink
Atmosphere
Soil organic matter
Ocean
Marine sediments and sedimentary rocks
Terrestrial plants
Fossil fuel deposits
Amount in billions of metric tonnes
578 (as of 1700) to 766 (as of 1999)
1500 to 1600
38 000 to 40 000
66 000 000 to 100 000 000
540 to 610
4000
a) Suggest reasons as to why marine sediments and sedimentary rocks are able to store such
vast amounts of carbon compared to terrestrial plants
b) Describe steps you would take to assess the reliability of the data presented in the table
DP8 – Gather and process information from secondary sources and use available evidence to
analyse differences in the composition of the oceans before and after the evolution of
photosynthesis
The Earth’s oceans are believed to have formed 3.9 billion years ago from water vapour derived from the
degassing of the mantle and bombardment of comets. The evolution of photosynthesis is 3.5 billion years
ago, however, changed the composition of the oceans forever.
a) Analyse the differences in the composition of the oceans before and after the evolution of
photosynthesis
b) Assess the accuracy of the information which identifies the appearance of
photosynthesising bacteria as a causative agent for the changes in the composition of the
oceans (Note: Search for evidence of ‘Banded Iron Formations’).
DP4 – Explain that reactions between oxygen and other elements would readily occur producing
oxide minerals and thus moderate the release of oxygen into the oceans and atmosphere
The evolution of photosynthesis was responsible for the production of oxygen in the early oceans
for over a billion years before the oxygen was able to reach the atmosphere
a) Identify the process that was responsible for moderating the release of oxygen into the
early atmosphere
b) Explain why oxygen did not reach the atmosphere for more than a billion years after the
first oxygen began entering the oceans