Sea level rising, but islands growing...?!

A couple of weeks ago I talked about how many island nations were at serious risk of inundation if sea levels rose. However there has in fact been some evidence that seems to have contradicted this! It has been argued that these islands are in fact growing! But how could this be possible, after having seen all the other existing evidence, pictures, and videos that clearly show how much of a threat the waters are to these islands?

A recent study by Kench and Webb (2010), where they used historical aerial photos and satellite images, has shown that 23 out of the 27 central Pacific islands studied either retained the same land area, or actually increased in size over the last 19-61 years, whilst the sea level rose by 2mm during this same period. (Edwards, 2010). 

Eroded coral debris had in fact been pushed back up towards the coasts by a mixture of wind and strong waves due to changing weather patterns  - Kench claimed that this showed how the islands were coping with the changes (Daily Mail, 2010).

So this study has given us a completely different perspective on sea level rise, and really makes one think about what other changes are taking place alongside it. Hunter made a good point by mentioning other issues which may affect this further, such as ocean warming, and acidification (Daily Mail, 2010).

There are clearly a number of different forces acting upon global ocean patterns and these small islands. Sea levels may be rising, but I think that in order to determine the fate of these islands, it depends on which forces have the greatest impact. The strength of the sea itself may be stronger and more destructive in some areas compared to others. Kench believed that the islands are simply moving with the changes. (Daily Mail, 2010). 

The diagram below is just an example that depicts changes in reef island characteristics of a selected part of Tuvalu (Funafuti Atoll) from 1984-2003.

It shows how these islands have altered their shape over this period of time.

However, one point to note with this study as a whole was that it explored Pacific reef islands; it does not account for other parts of the world, different coastlines, or even the other oceans and associated islands – sea level rise does still pose a threat to many other areas of the world and so the findings here cannot be generalised. Just thought it was interesting though, as the evidence does seem to legitimately show the islands that were studied have grown! This is still quite a fresh discovery, and I think more studies are required to explore these findings, and to show us further evidence that this really is the case.

References

Anonymous (2010) ‘Low-lying Pacific islands 'growing NOT sinking' as sea levels rise’, Daily Mail: http://www.dailymail.co.uk/sciencetech/article-1283669/Low-lying-Pacific-islands-growing-sinking-sea-levels-rise.html#ixzz2DeAXQ4Qr

Edwards, T. (2010) ‘Pacific islands ‘growing not sinking’, as sea levels rise’, The Week: http://www.theweek.co.uk/politics/14185/pacific-islands-%E2%80%98growing-not-sinking%E2%80%99-sea-levels-rise#

Kench, P. & A. Webb (2010) The dynamic response of reef islands to sea-level rise: Evidence from multi-decadal analysis of island change in the Central Pacific, Global and Planetary Change, 72 (3): 234-246 http://www.pacificdisaster.net/pdnadmin/data/original/SOPAC_2010_The_dynamic_response.pdf