Geology Reference
In-Depth Information
(ii) Define residence time and outline the factors that influence the
residence time of an element in the ocean. Provide examples of
oceanic residence times for elements that span the time scale.
(iii) Define salinity. What are the notable variations in sea salt, in
terms of concentration and composition, in the world ocean?
(iv) Using data available in Table 4, calculate the concentration of
H
2
CO
3
in seawater at 51C in equilibrium with atmospheric CO
2
at 370 ppm.
(v) Calculate the speciation of H
2
S in seawater at pH 8.3 at 251C
given that pK
1
¼
7.1 and pK
2
¼
17.0.
(vi) Explain how DMS of marine origin might affect global climate.
(vii) What are the major nutrients in the ocean? Describe their
concentration profiles and account for any differences between
them according to chemical behaviour.
(viii) Describe the different types of depth profiles that various metals
exhibit and explain how differences in their profiles originate.
(ix) Assuming all g
0
s
¼
1, calculate the speciation of lead in seawater
at 251C given the following values for stability constants for the
chlorocomplexes (K
1
¼
10
7.82
, b
2
¼
10
10.88
, b
3
¼
10
13.94
, b
4
¼
10
16.30
). Note that [Cl
] is 0.559 mmol L
1
.
(x) With specific reference to Question 9, outline the potential
limitations of using equilibrium models to explain chemical
behaviour of trace metals in seawater.
(xi) Describe the classification of marine sediments and give exam-
ples of each sediment type.
(xii) Why do suspended particles exhibit a surface charge and how
could this characteristic moderate the composition of ocean's
waters?
(xiii) With respect to estuarine chemistry, describe conservative and
non-conservative behaviour and provide examples of cationic
and anionic species for each category.
(xiv) What natural processes are responsible for weathering an oil slick?
(xv) Why is tributyltin considered such a potent pollutant in the
marine environment?
REFERENCES
1. R. Chester, Marine Geochemistry, Unwin Hyman, London, 1990, 698.
2. P. Tchernia, Descriptive Regional Oceanography, Pergamon Press,
Oxford, 1980, 253.
