Via press release today from the University of Alberta.
The days are getting longer
Scientists reveal that the rotation of Earth’s core holds a clue to understanding global sea-level rise
Scientists are studying past changes in sea level in order to make accurate future predictions of this consequence of climate change, and they’re looking down to Earth’s core to do so. “In order to fully understand the sea-level change that has occurred in the past century, we need to understand the dynamics of the flow in Earth’s core” says Mathieu Dumberry, a professor in physics at the University of Alberta.
The connection is through the change in the speed of Earth’s rotation. Melt water from glaciers not only causes sea-level rise, but also shifts mass from the pole to the equator, which slows down the rotation. (Picture the Earth as a spinning figure skater. The skater moves his or her arms in to spin more quickly or out to slow down.) The gravity pull from the Moon also contributes to the slow down, acting a little like a leaver break. However, the combination of these effects is not enough to explain the observations of the slowing down of Earth’s rotation: a contribution from Earth’s core must be added.
One of only a few people in the world investigating changes in Earth rotation, Dumberry contributed his expertise on Earth’s core-mantle coupling to the study. “Over the past 3000 years, the core of the Earth has been speeding up a little, and the mantle-crust on which we stand is slowing down.” As a consequence of Earth rotating more slowly, the length of our days is slowly increasing. In fact, a century from now, the length of a day will increase by 1.7 milliseconds. This may not seem like much, but Dumberry notes that this is a cumulative effect that adds up over time.
Based on their work reconciling these discrepancies, the scientists involved in the study are confident in predicting sea level to the end of the 21st century. “This can help to better prepare coastal towns, for example, to cope with climate change,” says Dumberry. “We’re talking billions of dollars of infrastructure here.” Dumberry notes that this study serves as a stimulus for more work to continue investigating the deep interior of our planet.
The findings, “Reconciling past changes in Earth’s rotation with 20th century global sea-level rise: Resolving Munk’s enigma,” were published in the December 11, 2015 issue of the journalScience Advances.
With 12 climate change-related centres and institutes and 24 climate change-related Canada Research Chairs, the University of Alberta is committed to researching the causes and effects of climate change. Researchers study past climate changes to better predict future changes.
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Given past glacial periods and interglacials, how much did the Earth speed up at the end of the a glacial and how much did it slow down when the ice returned? When we go back into a glacial period, what will the 1.7 millisecond be worth?
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Dr. Nils-Axel Moerner had this covered years ago in the 1992 Journal of Coastal Research:
http://journals.fcla.edu/jcr/article/view/78939
Home > Vol 8, No 4 (1992) > Morner
Sea-Level Changes and Earth’s Rate of Rotation
Nils-Axel Morner
Abstract
The mean global sea-level changes today and in the near past (and by that also in the near future) have not been able to establish in a satisfactory way, either by mathematical treatments of tide-gauge data, by geophysical modelling or by geological considerations. We here propose 8 new means of studying global mean sea level; viz. changes in the Earth’s rate of rotation (the variations in the length of the day). Any global change in sea level must be seen in the Earth’s rate of rotation as this is a direct function of any change in its radius. The decadal changes in rotation swing around a sinusoidal, about century long, mean trend that might represent such a global sea level factor. This factor is consistent with a sea level rise in the order of 11 cm in 100 years (which is a fraction of often claimed values for the hypothetical greenhouse generated sea level rise today and in the near future). This can be taken as a measure of the maximum possible rise in global mean sea level during the last 150 years. It can, however, not be excluded that it represents the interchange of angular momentum with a more slowly moving oceanic intermediate or bottom water currents. If so, there would be no significant global rise in mean sea level during the last 150 years. The recording of LOD changes is a powerful tool for monitoring and predicting global sea level changes.
He says the core is speeding up while the mantle is slowing down. I’m trying to digest that, but I think I need some bicarbonate. So my first question would be, and where is the energy that would be needed to “speed up” the core coming from? Like plate tectonics, I have to constantly ask, WHERE is the power source that is forcing a 50 mile thick plate to sink and go under another 50 mile think plate? And now I have to ask where is the power source for “spinning up” the core coming from? There seems to be so many dynamic motions on going, and there appears to be no increase in energy available to cause them.
Length of Day is a predicter for global warming/cooling too:
Climate Change and Long-Term Fluctuations of Commercial Catches – The Possibility of Forecasting
http://www.fao.org/docrep/005/y2787e/y2787e00.htm#Contents
This article has fascinated me for years now.
From above mentioned article:
2.1 SUMMARY
A phenomenon of close correlation between the main climatic index dT and geophysical index (-LOD) still remains an intricate puzzle of geophysics. Another challenging puzzle is the observable 6-year lag between the detrended run of dT and -LOD. Taking into account this lag, the LOD observations can be used as a predictor of the future climatic trends. Even without a mechanism for a causal relationship between the detrended climatic (dT) and geophysical (LOD) indices, the phenomenon of their close similarity for the last 140 years makes LOD a convenient tool to predict the global temperature anomaly (dT) for at least 6 years ahead.
Willis? Would you be interested to take a look? You would make me so happy!
Or is there a geophysicist in the room who would like to do it?
He’s claiming the planet spins slower, but if you ask me, the world runs a lot faster, these days.
Just what is a “leaver break”? Presumably the author meant “lever brake” but I’m not even sure I know what that is in comparison to any other type of brake. I can’t imagine they’re trying to say that the earth has handlebars!
Mods
spam posting above
nishi December 14, 2015 at 10:14 am
But won’t the number of us who’ll be spinning in our graves in 100 years offset this? I don’t believe the paper took that into account.
There is a very strong correlation between changes in the Earth rotation and El Niño.
One theory says that changes in the Earth rotation weaken the trade winds and cause the conditions that cause an El Niño.
The other theory is that El Niño conditions weaken the trade winds that cause a change in the Earth rotation.
I like the second one better.
And therein lies the rub – cause and effect. I don’t like either, the numbers aren’t good enough.
This is another piece of alarmist garbage. Yes, the Earth’s rotation may slow by 1.7 milliseconds per century, but at best this is merely an academic curiosity. The implication in the authors comment “these effects add up” is one of inexorability. What he (conveniently) forgot to mention is that unlike the rotational loss due to tidal effects, this effect does not loose angular momentum which must remain constant.
All that happens is that some mass is rotating further from the axis and this must result in a lower angular velocity in order for the angular momentum to remain constant. At the point when sea levels begin to decline again. the whole show reverses and rotation rate will increase.
A change of 1.7 msec/century in the length of the day is a change of 17 usec/year, or a change of roughly 6 msec in the length of the year from one year to the next. This isn’t enough to matter for ordinary life, but I estimate that GPS systems would drift by a couple of metres a year if this weren’t accounted for. (I just woke up so this could be completely wrong.) It’s partly because of this effect that since the current definition of the second was adopted, NO day has been 86,400 seconds long. It’s also because of changes in the LOD that we have leap seconds to deal with, horrible things that they are.
Earth’s rotation slow by 1.7 milliseconds per century so that’s why I’m always late for things
aint science wonderful !!
From a discussion on the CBC article: Peltier is rather unimpressed…
“But the mystery may not be quite resolved, according to some. William Richard Peltier, a professor of physics at the University of Toronto, takes issue with some of the paper’s key points. Peltier was not involved with this paper, but is familiar with much of the work that went into it — Mitrovica was one of his doctoral students, and some of Peltier’s own work was incorporated into Munk’s original calculations.
Peltier’s main issue with the argument in the paper has to do with the new viscosity model — the model of the way the Earth flows — that the authors used to help account for the ice age effect. Previous research has suggested that this model does not match up with observed data on the way the Earth’s geology actually behaves, Peltier said. In essence, he claims, this aspect of the paper is “absolutely incorrect.”
https://www.washingtonpost.com/news/energy-environment/wp/2015/12/11/scientists-may-have-just-solved-one-of-the-most-troubling-mysteries-about-sea-level-rise/
Peltier was one of the key authors with Clark and Farrell of the seminal paper in 1978 titled global changes in post glacial sea levels: a numerical calculation.
I guess the young gun is visibly trying to make a name for himself and thus dabbling in climate related stuff… since the viscosity of money flow to climate related subjects is decreasing…
Scientist Mathieu Dumberry must be proud to have his name endorsed by this blog.
As long as he doesn’t read it. This one qualifies for the “wall of shame”.
The picture looks at first glance like Pee Wee and Globie.
Obviously, this article is all about “spin”.
I could not help it. Its one of those mornings. — Eugene WR Gallun
Eugene, we both know this isn’t about scoring points, but that was worth 100 for the pun alone, in my book.
Let alone it was deadly accurate…
Steve L
I’m surprised it took someone this long, but kudos for being the first.
if I fart that would actually change the earth rotation….so what….it only leaves the same smell in the room as this article
I think the very last paragraph really tells you all you need to know
“With 12 climate change-related centres and institutes and 24 climate change-related Canada Research Chairs, the University of Alberta is committed to researching the causes and effects of climate change. Researchers study past climate changes to better predict future changes.”
So, the only way this guy could get funding at the UofA was to use a ridiculous AGW tie in.
When you have a hammer, its amazing how many things look like nails.
Amazing that organizations designed to find stuff actually find stuff. Even if it isn’t always the stuff they are actually looking for…
It’s Di Skewlawats Happinennow ayy?
If that was too cryptic, I mean this institution follows the popular funding.
Here is my question. Now that NASA has shown that the ice in Antarctica is growing; and knowing that ice in the arctic is floating (i.e. already displacing water, so not changing the mass distribution), only Greenland is at issue here. Does this change the results of this modeled ‘study’?
I don’t know if his idea is right or not but at least he got through without mentioning CO2, which is worth a couple of merit points.
Sorry, he used: “this consequence of climate change”, and the politically correct definition of climate change implies anthropogenic causation. Of course, there is also the implication of linear warming in the PC definition, which is the only scenario under which “this consequence” (however consequential it might be) could possibly occur.
Sea level rise is more less constant, due to river silt deposits oceans and volcanic activity. Basically for every cubic meter of mud deposited from river into ocean, sea level rises as there would be one cubic meter of water more. Same with volcanic activity, for every cubic meter of magma from underwater volcano there is sea level rise of one cubic meter water.
So there is amount of sea level rise which is constant and normal. Regardless Earth ice sheets and spin rate conditions.
You didn’t mention sublimation (settling and sinking) of the coastal areas as a contributor to SLR statistics.
An aeonic time scale more like. isn’t it fun to split hairs over insignificant scientologic meanderings?
hmmm who cares if the day is 1.7 milliseconds longer or if it was 1.7 minutes longer, or even shorter. I understand it would change the weather in the short term. But in the years, decades, centuries time frame on a global scale wouldn’t that extra time be spent equally in day and night time (and all other times) resulting in net ZERO. IOW 365 day orbiting the sun is the same wither the earth rotates 365 times or 364 times when it comes to how much heat is absorbed\released.
Now if they had a study saying that this faster \slower spinning resulted in more\less cloud cover or something
According to this article,
http://www.livescience.com/50545-most-precise-atomic-clock.html
“time ticks faster at different elevations on Earth”
Just looked in my ‘Crystal Ball’ and I see many ‘Seance’ PHd’s breeding on this one.
‘A Study of Longevity of Life at Low Altitude’
Or maybe Estate Agents jumping in, ‘Your Mountain Chateaux is Killing You,straight swap for Beach Hut’
Sarc.
From the article above:
“…
Melt water from glaciers not only causes sea-level rise, but also shifts mass from the pole to the equator, which slows down the rotation.
…”
While here we learn:
http://news.yahoo.com/earth-may-spin-faster-glaciers-melt-150016710.html
“…
When polar ice caps melt, they remove weight off underlying rock, which then rebounds upward. This makes the poles less flat and the planet more round overall. This should in turn cause Earth to tilt a bit and spin more quickly.
…”
Slower, faster? My head is spinning
Sooooo…in 10 thousand years we should start caring about this ???