By Daniel Fitzhenry March 2019
The seas and oceans to the east of Australia forms the largest body of water on Earth. This broadly connected vast body of water presents a genuine sea level. The Sydney Fort Denison Recording Station provides stable, accurate and genuine mean sea level data. The following table shows mean sea levels at 10 year intervals and these levels are related to Chart Datum which is at the lowest spring tide level.
100 YEARS OF MEAN SEA LEVELS AT FORT DENISON, SYDNEY:
1914 – 1.11 metres
1924 – 0.98 metres
1934 – 0.98 metres
1944 – 0.97 metres
1954 – 1.00 metres
1964 – 1.09 metres
1974 – 1.09 metres
1984 – 1.02 metres
1994 – 1.04 metres
2004 – 1.08 metres
2014 – 1.12 metres
2019 – 1.05 metres
Accordingly, the mean sea level at Sydney in 2019 is 6 centimetres lower than the mean sea level at Sydney in 1914 when the Bureau Of Meteorology commenced recording Mean Sea Level.
High Sea Levels during Storm, Cyclone & Low Pressure Events.
Ill-informed commentators have asserted that sea levels may permanently rise by 1 to 2 metres in the next 100 years. 100 years of records on the largest water body on Earth indicates that this is incorrect.
There have always been short period storm and low pressure rises in sea levels. The highest recorded sea level at Sydney occurred during the 1974 low pressure storm. The sea level rose to 30 cm above high spring tide level for one day. During recorded history there has been no indication whatsoever of a 100 to 200 cm permanent rise in sea level.
There will always be short period storm, cyclone and low pressure rises in sea levels in close proximity to cyclone and storm centres. These storm centre rises in sea levels are not permanent.
Ocean swells and storm waves can exceed 16 metres during major storm surge events. It is these massive waves that have caused significant damage to coastal and island communities in the past. It is certain that huge storm event waves will occur in the future and will cause significant damage to the island and low lying communities. Coastline and flood zone protection is the sane answer to storm event damage.
It is polite and essential that the world population should avoid incorrect climate nonsense. We need to divert the alarmist energy to caring for the planet. Cease polluting the oceans. Prevent development of flood prone land and threatened coastal zones that have been, and will always be, subject to flooding.
Dan Fitzhenry.
Capt. Daniel Fitzhenry – CPHS1 Hydrographic Surveyor – Registered Surveyor – Dip. Environmental Studies (Macq.)
Steven Fitzhenry – B.Eng. (Civil) Sydney – MIE Aust. – Maritime Civil & Structural Engineer – Project Manager
Capt. Adam Fitzhenry – B. Eng. Honours (Civil) Syd, MBA AGSM – Maritime Civil & Structural Engineer – Oceanographer
Ellie Fitzhenry – B.Sc (Sydney) – Marine Biology & Ecology – Marine Science
Capt. Paul McGaw – ROV Operations Manager – Electrical & Mechanical Engineer
Tracey Hay – B.A (Macq) – Project Coordinator – IT, Statistics & Research Manager
PDF version: https://saltbushclub.com/wp-content/uploads/2019/07/sydney-sea-levels.pdf [196 kB]
And confirmation on the incomplete data (which is the entire premise of Capt. Fitzhenry’s position) from BOM today
Hi David
Yes, the May 1914 monthly statistics were derived from ten consecutive hours at the end of the month. Our records begin at 1914-05-31T14:00:00Z.
Sidenote: While we include the statistics in the data file, we typically only plot a monthly value if the data return during that month exceeds 50%.
I hope that helps.
Kind regards,
James
James Chittleborough | Assistant Manager, Tidal Unit
Interesting results and interpretations you have presented. Your selective data and resultant trend seems to conflict with the more complete data set accessible from BOM (http://www.bom.gov.au/ntc/IDO70000/IDO70000_60370_SLI.shtml) and PSMSL (https://www.psmsl.org/data/obtaining/stations/65.php).
Would you like to suggest a reason for this?
The BOM tell lies Stuart and they’ve been caught out several times. The last three or four Winters in Sydney have been abnormally cold and the Summers, well they haven’t existed for me and I’m one who feels the heat. It feels more like ‘global cooling’ to me. It’s the end of January and I’ve only just taken off my doona. Unheard of at this time of year. I have lived near the water for years and both Clark Island and Shark Island look exactly the same as they did years and years ago. I can’t see Fort Denison, but the figures in this article say it all don’t you think?
Healthy scepticism and intelligent questioning are fine , but really Mr Fitzhenry , your assertions about Sydney sea levels are not statistically sound , are ill informed and frankly ridiculous . I have just been through the same process as David Driscoll and arrived at the same result . The May 1914 figure of 1.111 m is the result of 10 hours ONLY from a possible monthly total of 744 hours , and as such should be DISCARDED in any meaningful analysis of means . “Ill informed commentators” ; indeed Mr Fitzhenry !
These conclusions are misleading. For example, the mean sea level change over the interval 1924 – 2014 is 14cm, or a mean sea level increase of 1.56 mm/year.
As a previous reply has noted, your statistical methods are unsound and the data for 1914 is absurdly unreliable: you cannot calculate a monthly average from 10 hours of data.