1.3.1.6 Importance of reefs for the human society (cont...)
e) Reefs in environmental and climate research
This is a topic of such relevance that we will treat it in an own section later in this course (see section 9.4). Here is just a small preview.
Scleractinian stone corals and some other organisms such as coralline sponges secrete annual skeletal layers which may be compared to annual growth rings of trees. These layers include chemical information on the ambient sea water, particularly on the sea water temperature at the time of creation of this growth ring. Since corals frequently are several hundreds of years old (living methusalem corals may be 1000 years old or more), these skeletons provide a phantastic climate archive which is a most important data base for climate reconstruction and development of climate models. Temperature information is preserved as distinct proportions of stable oxygen isotopes.
Fig.: Partially eroded calcareous skeleton of massive skleractinian coral showing annual growth layers. Single layers are about 0,5 to more than 1 cm thick. Used with permission.
Corals can also preserve other information such as pollution events by hydrocarbons, radioactive fallout or heavy metal accumulations.
The climatic importance of reefs for buffering sea water chemistry and their role the carbon cyle was already discussed in section 1.3.1.3
We will come back to all this in section 9.4
Further reading on stable isotopes: see our isotope course manuscript of the GeoBio-Center at LMU.
There are many other, mostly damaging aspects of use of modern reefs, such as:
g) Importance of fossil reefs for human society
We have already mentioned the economic aspects of fossil reefs for hydrocarbon exploration, stone industry and pharmaceutical industry (see 1.3.1.5 potential jobs) and will come back to this in more detail in section 9.1.
In addition, fossil reefs frequently have a high touristic value since they tend to form impressive rocky or mountaneous landscape. Just giving examples from Germany, Devonian reefs form beautiful sceneries in the Eifel hills, Jurassic reef relics are the major landscape-forming factor of the impressive Swabian and Franconian Alb, and Triassic reefs form well known mountain climbing peaks such as the Ross- und Buchstein and the Plankenstein, or the highest mountains of Germany, the Wettersteingebirge, including the Zugspitze. The bizarre peaks and massives of the Dolomites, Southern Alps also represent Triassic reefs and carbonate platforms.
The distribution pattern of ancient reefs may also be helful in testing and optimizing numerical computer climate models. We will come back to all this in section 9.4.
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Further reading:
Wells & Hanna, N. (1992): Das Greenpeace-Buch der Korallenriffe.- C.H. Beck, München (out of print, see libraries); also availabe in English (The Greenpeace-Book of Coral Reefs), out of print, see libraries.
Kühlmann, H.H. (1984): Das lebende Riff.- Hannover (out of print, see libraries)
Relevant articles in: Steiniger, F. & Maronde, D. (eds)(1998) Städte unter Wasser – 2 Milliarden Jahre. Kleine Senckenberg-Reihe, 24, Kramer, Frankfurt/M.
Relevant articles in: Leinfelder, R., Kull, U. & Brümmer, F. (eds): (1998): Riffe – ein faszinierendes Thema für den Schulunterricht. Materialien für die Fächer Biologie, Erdkunde und Geologie.- Profil, 13, Stuttgart (out of print but free available online at www.riffe.de/schulbuch)
Die Riffe und der Mensch: Ein Dilemma? online article by Reinhold Leinfelder and Franz Brümmer (1997), in german.
This page is part of www.palaeo.de/edu/reefcourse,
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