A short comment by Nils-Axel Mörner
UPDATE: See the follow up post here: The Most Important Sea Level Graph
This is the sea level graph (from Kwajalein) recently being circulated and claimed to show an alarming acceleration of a proposed general sea level rise.
Yes, this curve rises fairly rapidly from 1990 to 2012. But for what reason and with what regional message?
This is a sea level graph (from Majuro) and is shows a general sea level stability from 1992 to 2010.
No traces of any acceleration!
(Note from Anthony: see more on Majuro here: http://www.gloss-sealevel.org/publications/documents/pacificcountryreport_mi.pdf )
It looks like Kwajalein is affected by a local subsidence induced by building construction (or some sea level “correction” in order to have it going up).
The Majuro records, for sure, contradicts and acceleration claim; even a general “rise”.
In conclusion, don’t “hang your hat” on the Kwajalein graph. Look around and observe!
What an insanely cherry-picked Majuro graph. You do know that people can look up the lower levels prior to the ’90’s and the acceleration since 2010, right?
REPLY: The issue is about the acceleration post 1990. The graph is valid for that purpose. Get over yourself.- Anthony
Jonathan- you say-
“Out of interest I downloaded the data for Majuro ( http://www.psmsl.org/data/obtaining/stations/1838.php ) and calculated the slope from 1993-2010 using linear regression, and got it to 3.9 mm/year, with 95% confidence interval of 2.0-5.8mm/year.”
NOAA Tides and Currents gives an estimate of error bars for tide gauge SL trends, based on length of record. For example, this is the link from the record for St. Petersburg, FL.
http://tidesandcurrents.noaa.gov/sltrends/sltrends_update.shtml?stnid=8726520
NOAA states that a 20 year record length has an error of +/- 2.9 mm/year, which gives a confidence interval of 1.0 – 6.8 mm/year.
This assumes that vertical land motion can be ignored (ho ho!).
chris y: Thank you for the link! As I understand it, the estimate of error for a given record length given in your link is some mean value for all the stations considered in the referenced data.
That would mean that there could be variations in error estimates for different stations. However, my error estimate for Majuro is noticeably smaller than the one you reference. Although this might be possible, when I redo the sam calculations for Kwajalein, my errors are only about half of what they report ( at http://tidesandcurrents.noaa.gov/publications/Tech_rpt_53.pdf ), and mean value is off as well. So it seems like I need to look into my calculations, and their methodology, to see where the differences come from.
Robert Clemenzi says:
July 31, 2013 at 6:17 pm
Try again – coral does not grow above the water.
===============
To call an atol an island is a mistake. A coral atol is a massive living structure, on a scale we find hard to recognize. The fringe that surrounds coral atols are about 6 feet above sea level worldwide, in spite of a rise in sea level of a few hundred feet over the past 20 thousand years. At the same time the atols themselves are sitting on top of massive volcanoes, that are sinking into the earth due to their weight and the plasticity of the earth’s crust, and the thinness of the crust at the bottom of the oceans. How do they achieve this? How do they manage to stay 6 feet ahead of the oceans?
The secret is quite simple. Wave and wind action from outside the reef pounds the reef day and night and continually piles coral rubble towards the center, where it is bound up by vegetation to form the ring of small islands that fringe the atol. The atol is almost always accumulating the fastest on the side facing the prevailing winds, where the surf is the strongest The buildings and man made structures that sit on top of the rubble cannot grow the way the plants do, so eventually they must be rebuilt higher to remain above sea level. In the center of the atol there is a shallow lagoon, where there was at one time the peak of the volcano, that has long since sunk out of sight, and the resulting hole filled in by the coral rubble.
Fresh water from rain that accumulates in the lagoon and forms a lens in the surrounding ring of islands inhibits the growth of coral in the lagoon itself, though it is not unusual to find “coral heads” that rise up from the bottom and present a hazard to boats. Many atols have a pass on the downwind side of the atol that has been carved over time by the action of the wind sweeping the fresh water out of the atol and in doing so inhibiting the growth of coral in the pass.
Update to my previous comment: Okay, they make a number of corrections for Kwajalein, so they don’t calculate the same slope as I do, which probably accounts for all the difference.
Willy Soon on sea levels.
Five or More Failed Experiments in Measuring Global Sea Level Change. Willie Soon, Ph.D.
Jonathan-
“chris y: Thank you for the link! ”
You’re welcome.
Eli Rabett says:
July 31, 2013 at 7:23 pm
Kwajalein is in the Western Pacific, an area of significant sea level rise as measured by satellites since 1992.
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the graphic shows 1/2 the pacific rising and 1/2 the pacific falling. this is not sustainable. at some point in time the water from the higher 1/2 will flood back into the lower 1/2, forming a tsunami that will wipe out any land surrounding the lower 1/2. the entire west coast of the US will be lost. millions will die. however, that is only the beginning. the rapid change in mass distribution will throw the earth out of orbit and into the sun, leading to run-away global warming.
http://www.cmar.csiro.au/sealevel/sl_hist_last_15.html
“During El Niño years sea level rises in the eastern Pacific and falls in the western Pacific, whereas in La Niña years the opposite is true.”
With the temperature rising in the south pacific, it is no wonder that sea level is rising, after all, water expands as it warms.
Ah ha! Go find that senator who thinks islands can tip over! He needs that graph for his next presentation!
The 2012 NOAA paper by Leuliette “The Budget of Recent Global Sea Level Rise” reports that global sea level is rising by 1.1 mm per year with an error of 0.9 mm per year.
The Kwajalein data needs to be audited, or at least checked by an unbiased outsider.
There should be photos of dock pilings over the years that could be used as a sanity check.
For example, the Arizona memorial was constructed in 1960. Comparing photos of the pilings to today shows no change in sea level in 50 years at Pearl Harbor.
Is this really a post from N-A Mörner? It is very short, incomplete and as it seems at least to some extent, wrong.
I have never regarded Mr Mörner as laconic. He usually likes to explain things to the detail.
Could it be someone else posting?. (Tamino was quick with a comment.)
Philip Bradley says:
July 31, 2013 at 3:39 pm
Kwajalein is a seamount atoll. An atoll formed on top of an extinct volcano. You can think of the volcano as a big pile of rubble that settles over time, lowering the surface of the atoll.
Nearly all Pacific atolls began their existence as reefs around volcanic islands. The volcanoes themselves generally began as mountains on hot spots, which are elevated. As the oceanic crust rides away from the hot spot the volcanism declines and the mountain – and the sea floor below it – gradually sink. The coral reefs continue to grow creating atolls as the mountain base and sea floor ride downward toward the abyssal plain. Everything is in motion and differentiating eustatic from isostatic changes is not trivial.
As others have observed you can’t deduce much from a single tide gauge record, so here’s a plot of mean relative sea level rise measured at 18 tide gauge records in the central Pacific outside Hawaii, data from PSMSL. (Hawaii is subsiding because of lithostatic compression so relative SLR rates here are significantly higher.)
http://oi41.tinypic.com/11ak7sh.jpg
Relative sea levels in the central Pacific have risen by about 100mm since the late 1940s. About half of this rise can be attributed to glacial isostatic adjustment, which is causing Pacific islands to subside at an average rate of maybe 1 mm/year. The rest is a result of meltwater addition or thermal expansion.
The plot also shows the rate of SLR in the central Pacific accelerating after 1990, as it did in several other parts of the world. Globally, however, sea levels rose at least as fast if not faster in the 1930s and 1940s.
Waiting to hear a response to Tamino’s http://www.weather.com/video/town-will-disappear-by-2025-38176.
Aren’t y’all a bit embarrassed?
There’s no “adjustment” – the SOI went positive in 2010:
http://www.bom.gov.au/climate/current/soi2.shtml
… and drove sea level up at most western Pacific stations including Majuro and Australian (N and NW) stations. Majuro has a continuous GPS station – BOM/CGPS data shows no significant subsidence of station nor gauge over the entire record.
Two questions:
1. If up-to-date data (to last month) and a plot is available, why show a Majuro plot to end 2010?
http://www.bom.gov.au/ntc/IDO70052/IDO70052SLI.shtml
2. Why blank out the last two grid boxes on the Majuro plot which is from 2012? Something to hide? Majuro data to last month shows a similar uptick to Kwajalein, and it also shows a downturn since the peak in 2011, following the SOI.
SOI goes up and down; sea-levels in the western Pacific follow suit. Learn from it, and move on.
This brings back memories of when I worked at Lincoln Lab
in the 1960’s and worked at Kwaj a few times with the TRADEX
radar. I even got to see a missile re-entry at night.
Thanks for the Willie Soon video.
Another famous place is the Tuvalu Islands, which are supposed to soon disappear because they’ve put out too much carbon dioxide. There we have a tide gauge record, a variograph record, from 1978, so it’s 30 years. And again, if you look there, absolutely no trend, no rise.
– Dr. Nils-Axel Mörner (2007)
url="http://www.psmsl.org/data/obtaining/rlr.monthly.data/1452.rlrdata"
rlr=read.table(url,sep=";",na.string="-99999")
lm(rlr[,2]~rlr[,1])$coeff[2]
In short, look around and take Dr, Mörner with a grain or two of sea salt.
The sea level surface is not spherical. It is not even ellipsoidal. It is a complex surface defined in terms of tesseral harmonics of the gravity potential of the Earth. The gravity potential is a function of the distribution of mass, including that of seawater. If there are changes in the terrestrial mass distribution that alter the amplitude coefficients of the gravity potential’s harmonics, the configuration of the “lumpiness” will change. This can result in the potential going up by a few inches in one place and down by a few inches in another place, without changing the total quantity of seawater. Details, details….
Just by the nature of the name, I always thought Willie Soon was a Netherlander. Guess not.
I looked at the NOAA web page (http://tidesandcurrents.noaa.gov/sltrends/index.shtml) and zoomed in on The Marshall Islands and if you click on Kwajalein you see 1.43 mm/yr riae and 3.60 mm/yr rise on Majuro. Looks to me like there is a rise for both stations as well as for almost all of the Pacific. A blue arrow downward show sea level drops and that is primarily along Alaska’s coast. If I were a Pacific Islander I would be concerned.
Thanks for the Willie Soon video. Excellent!
You should watch Willie Soon’s video for an explanation of the measurements.
Hotels and tourists are heavy, man!