This post is somewhat wide-ranging. But bear with me, because it is all about the influence of the moon. At Sunday 4 June at 12.43 am, Norfolk Island time, there will be a full moon. We all know that the moon affects our tides, and the weather, too, in some very subtle ways.
Corals just beneath the surface can become exposed at low low tides, Cemetery Bay, Norfolk Island
When there is a full moon or a new moon, the sun, moon, and Earth are in alignment, and at these times (usually a day or so later), we can expect larger variations in the tides. At this time, the gravitational attraction of the moon lines up with that of the sun, producing higher and lower tides by as much as 20 per cent when compared to the average tide.
Sailors have an old saying, that a full moon eats clouds. Like those sailors, I often observe that around a full moon we experience a period of calmer weather followed by some unsettled weather in the days afterwards. Of course, the Earth’s weather patterns are complicated and there are many factors overlaid on each other at play, so this isn’t always the case by any means.
The view from Point Hunter towards the Kingston Pier at low tide
According to the tide charts, this Sunday and Monday we are in for some low low (spring) tides in the afternoons (1.52 pm at 0.29 m, and 2.34 pm at 0.27 m respectively). This means there may well be a few corals exposed. This is normal. Corals have their own way of coping with this.
When corals are exposed there is often a distinctive odour caused by the mucous they exude in order to protect themselves from the warm afternoon sunlight. If you are snorkelling at this time, you can see filaments of the pinky coloured mucous floating around the water column before these get dispersed by the incoming tide. The chemical that makes this odour is called dimethylsulfoniopropionate, or DMS for short.
Interestingly, DMS is a ‘keystone’ chemical, which influences many things, ‘from the presence of birds to the formation of clouds’. An article in The Atlantic explains how this chemical indicates the presence of plankton, which in turn attracts albatrosses, petrels and shearwaters to find food.
Worryingly, the plastic that we dump in the ocean becomes home for many living things, including microbes and algae. These give off that same DMS signature smell, sending out a siren call to these birds to come and feed – with disastrous consequences if they ingest the plastic. I encourage you to read the article for more information.
But I digress.
With the low, low tides, the bays are really like a huge, calm swimming pool, giving us some great snorkelling opportunities. These low tides should also let us view the causeway, which will no doubt be exposed too. The Sirius ran aground with disastrous consequences in March 1790 and this causeway is thought to have been built to the outer reef in order to facilitate salvaging its cargo. We have no firm proof about this, though. Others claim the causeway was built to enable stone quarried on the reef to be brought to shore. Either way, the first time the structure appears on a map is in 1900.
You can click on the map below to see a larger version.
A honey moon
In Europe, the June moon is known as the ‘honey moon’ because that is when the honey was harvested. And with June being a popular month for weddings … the rest, as they say, is history!
Crop from Murphy, M. V & Gullick, W. A. 1904, Map of Norfolk Island shewing grants and subdivisions 1904 W.A. Gullick, Government printer, Sydney, N.S.W.
The causeway to the outer reef, just opposite the Blacksmith’s yard, Kingston, Norfolk Island
If you want to know how the full moon affects Brian’s breakfast plans, then you can read my rather tongue-in-cheek article ‘A fried egg is not a feminist issue’ on my rather neglected Norfolk Island Time website.