Ric, having visited Niku so many times over the years, how has the shorline changed since the first time you visited? Ovbiously there has been damage and overwash from storms and the proliferation of various foliage but has the overall shorline changed, such as the reef flat? Do you notice that the tides seem lower or higher. Does the island seem like it changes or does it seem relatively the same? I always found it fascinating. Its so far from nowhere and just sits there alone. It has to be surreal every time you visit.
Krystal
Yes, every time we get there it is surreal, a magical moment realized, with Nei Manganibuka presiding. Hard to describe the experience, but it is a combination of expectation and imagination combined with the realization of reaching one of the most remote places on earth.
The shoreline has changed a bit over time but not so much since we've started visiting the island. There has been some discussion about storm damage between the 2001 and 2003 trips as observed by Howard Alldred during NIKU VP. He observed what he believed was significant erosion and storm damage on the colonial village side of the landing channel, which was widely reported at the time.
One of the problems with Howard's observations is that he had not been there in 2001, and I subsequently showed through comparative photos that the same features that Howard attributed to storms between 2001 and 2003 were actually already there when we visited in 2001.
That said, the island certainly is subject to terrific storm and waves at times, including the colonial village shoreline, but the overall shoreline hasn't really changed much since the first aerial photos were taken. In 2001, the Baureke passage was completely filled with sand, yet in 2007 and 2010 it was open and flowing. The cloudiness of the lagoon was adversely affected in 2001 (the year we did most of the lagoon diving) without the secondary channel to the lagoon.
Somewhere Ric did an overlay of the 1939 aerial photo with the 2001? sat photo that revealed much of the changes in shoreline. I'll see if I can dig it out.
In 2001, Gardner One, the Benchmark left by the NZ survey, was well within the sand bar just inside the passage, yet by 2010 it was standing out in the water by itself, so there definitely is movement of the shoreline with regards to the sand. My impression is that it comes and goes, year by year.
There is some evidence - aerial photos - that the shore near the 7 site has grown over time towards the sea, perhaps 100-200 ft since 1940.
Overall, we can see in historical photos that things like the delta of sand on the inlet side of the main channel has grown over the last 50 years but the basic shoreline is remarkably similar to what it was in 1940.
Overall, the atoll is essentially growing on the eastern side and getting eroded on the western side, but I don't think we can attribute anything to sea level rise - just yet. The effects of sea level rise are primarily to be seen in the future, but will be devastating to the current version of above high tide Nikumaroro. Ultimately, the reef will adapt and grow to meet the new sea levels, as it has in the past, and there will be an island or at least a reef there, but the areas of human habitation between 1937 and 1963 may be completely underwater in the future.
I hope that helps your understanding.
Andrew