From Oregon State University:
Ancient tides different from today – some dramatically higher
CORVALLIS, Ore. – The ebb and flow of the ocean tides, generally thought to be one of the most predictable forces on Earth, are actually quite variable over long time periods, in ways that have not been adequately accounted for in most evaluations of prehistoric sea level changes.
Due to phenomena such as ice ages, plate tectonics, land uplift, erosion and sedimentation, tides have changed dramatically over thousands of years and may change again in the future, a new study concludes.
Some tides on the East Coast of the United States, for instance, may at times in the past have been enormously higher than they are today – a difference between low and high tide of 10-20 feet, instead of the current 3-6 foot range.
And tides in the Bay of Fundy, which today are among the most extreme in the world and have a range up to 55 feet, didn’t amount to much at all about 5,000 years ago. But around that same time, tides on the southern U.S. Atlantic coast, from North Carolina to Florida, were about 75 percent higher.
The findings were just published in the Journal of Geophysical Research. The work was done with computer simulations at a high resolution, and supported by the National Science Foundation and other agencies.
“Scientists study past sea levels for a range of things, to learn about climate changes, geology, marine biology,” said David Hill, an associate professor in the School of Civil and Construction Engineering at Oregon State University. “In most of this research it was assumed that prehistoric tidal patterns were about the same as they are today. But they weren’t, and we need to do a better job of accounting for this.”
One of the most interesting findings of the study, Hill said, was that around 9,000 years ago, as the Earth was emerging from its most recent ice age, there was a huge amplification in tides of the western Atlantic Ocean. The tidal ranges were up to three times more extreme than those that exist today, and water would have surged up and down on the East Coast.
One of the major variables in ancient tides, of course, was sea level changes that were caused by previous ice ages. When massive amounts of ice piled miles thick in the Northern Hemisphere 15,000 to 20,000 years ago, for instance, sea levels were more than 300 feet lower.
But it’s not that simple, Hill said.
“Part of what we found was that there are certain places on Earth where tidal energy gets dissipated at a disproportionately high rate, real hot spots of tidal action,” Hill said. “One of these today is Hudson Bay, and it’s helping to reduce tidal energies all over the rest of the Atlantic Ocean. But during the last ice age Hudson Bay was closed down and buried in ice, and that caused more extreme tides elsewhere.”
Many other factors can also affect tides, the researchers said, and understanding these factors and their tidal impacts is essential to gaining a better understanding of past sea levels and ocean dynamics.
Some of this variability was suspected from previous analyses, Hill said, but the current work is far more resolved than previous studies. The research was done by scientists from OSU, the University of Leeds, University of Pennsylvania, University of Toronto, and Tulane University.
“Understanding the past will help us better predict tidal changes in the future,” he said. “And there will be changes, even with modest sea level changes like one meter. In shallow waters like the Chesapeake Bay, that could cause significant shifts in tides, currents, salinity and even temperature.”
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Jay Davis says:
August 2, 2011 at 6:12 pm
“Understanding the past will help us better predict tidal changes in the future,”
“What a crock! We can’t predict climate. We can’t predict tectonic plate drift and speed. We can’t predict catastrophic meteorite or comet collisions (except when relatively imminent). In fact, there’s little we can predict about what the earth and its atmosphere is going to do in the long run. Period. We can only measure the changes as they occur and adapt to them. As for the tides, the current tide charts are perfectly adequate for the present”
I think a prediction is possible for functions in nature if one knows the function. The knowledge can be about the function in time/space, or on the physical process and its laws.
If a tide calendar predict the time and height of a local point for tomorrow, or for a day in the next year, then this is possible, because some people have fitted the functions of tide well in a mathematical simulation. This means – and I think this is an important point – that the tide is not simple to calculate out of Newton’s law, it is a play with geometry. It needed several mathematicians and 19 years to one a model had developed, which can compute the Tide exactly on 10 cm.
“The IUGG (international union for geodesy and geophysics) called an international working group in the year 1965 from mathematicians to assistance, who had come however after 10 years work to no solution contently placing. Their mathematical models provided for example for the Northpacific ebbs-tide ahead although floods were observed and turned around. In the year 1972 U.S. of satellite and/or rocket designs required a forecast of the Tide height on 10 cm exactly. After 6 years modeling time appeared the North pacific in the spring 1978 then in tidal situation true to nature. For this model moon and sun became mathematical because of their elliptical and inclined orbits by a row of fictitious moons and suns replaced. For an accuracy of 10 cm to reach, they needed 6 moons and 5 suns with 4 halv a day’s, 4 complete days and tree longer periods (14 days, month, and halv a year). After further 6 years the model was then extended of the North pacific.”
There are many functions known which give evidence that the solar system and the terrestrial climate of the past has a relationship.
http://volker-doormann.org/images/ghi4n_china_yang_122.gif
http://volker-doormann.org/images/gl_patzelt_ghi4.jpg
Finding the relevant real celestial functions, which can simulate in general the global climate of the past, then the prediction of the global climate is just as possible as the prediction of the tide. And that is not only an idea; it is realized by taking the functions of some 10 celestial bodies.
Running a simulation for the global temperature it is a calculation of geometry in time/space like the calculation of eclipses
http://eclipse.gsfc.nasa.gov/OH/OH2011.html#SE2011Nov25P
Accuracy. If we speak on global climate, we can speak on reconstructed and/or calculated (‘global’) temperatures. These temperatures are the result of the superposition of the terrestrial functions like the Chandler wobble to the solar functions. But they can separate because of their different geometries and time/space.
Richard111 says:
August 2, 2011 at 10:40 am
I live within 100 metres of an old fishing harbour. Built 150 years ago. Highest high tides hit 7.4 metres. It looks like the harbour could cope with a 1 metre rise – just! So current quoted sea level rises are a bit ho-hum. Sadly I will need around 15 metres of sea level rise to turn my property into true sea front category. 🙂
————
It’s a shame the same can’t be said for the 6 million people living on the Ganges Delta, 0.5m rise could see that many people made homeless. That’s relative sea-level change as well so a large part of that could come from subsidence of the delta.
King tides occur during a full moon. I had a marine aquarium inside a unit (condo) that faced the rising moons. I turned the tank lights out at night. Native sea anemones go to sleep in the dark by folding in their tentacles or arms whatever the right name is for them. I noted that during a full moon they would open their tentacles and some even moved slightly across the rocks to actually catch the moon. Even though their tank light was out and so was the room the aquariums were in. Now this was something I couldn’t explain readily. Because a full moon would only shine through the window for a short time before it reached its zenith in the sky?
But during the king tides in Cairns, northern Australia, a very popular tourist destination for international as well as Australians, the sea water comes up and washes down the gutters in the main street facing the ocean front. So you know that during a cyclone, heavy storm or tsunami people have been known to be warned to seek higher ground.
But the Australian alarmists some government ministers are now claiming that the East Central Coast will be inundated by rising sea levels if we don’t introduce a carbon tax. All coastal regions are popular tourist spots. Now I don’t know about coastal areas in the US, but homes/hotels near ocean views or on waterfronts are terribly expensive to buy. (Millions in fact). Did not stop Al Gore buying property in areas he reckoned would be inundated though.
What annoys me most is that although some islands are saying they are in danger of sea level
rises from climate change. It is total rot. Atolls are subject to storm damage and erosion. They come and go. But the UN Climate change fund want to compensate them for this climate change caused by developed countries. I lived in Bermuda, and that is a very low set island. They haven’t complained about rising sea levels have they? It’s made up of coral islands though.
SteveE says:
August 3, 2011 at 2:40 am
“”It’s a shame the same can’t be said for the 6 million people living on the Ganges Delta, 0.5m rise could see that many people made homeless. That’s relative sea-level change as well so a large part of that could come from subsidence of the delta.””
Nobody is forcing those people to live there. They chose to live there because it is generally very fertile soil so the can grow food they otherwise could not afford. It is the nature of the river delta that made such fertile soil available. River deltas tend to increase available land. Putting in too much control imperils those people just as much as floods and sea level rises (most unlikely scenario). Look at what happened with the River Nile flood plain after the dam controlled the flooding.
Crossopter says:
August 2, 2011 at 3:31 pm
“In answer to a question about tidal variation over geological time, Dr Russ Evans of the British Geological Survey gives a short and interesting reply:
“Based on information obtained from tidal rhythmites, Williams (2000) showed that at 620Ma the Earth-Moon distance was 0.965 of its present value, and that at 2450Ma it was 0.906 of its present value…”
If Dr. Evans is correct, this poses a problem regarding our understanding of what gravity is and how it operates. It is thought to an attraction, so how does it transmit the changes in tangential velocity needed by the moon for it to maintain it’s orbit, or perhaps the moon has a hidden rocket propulsion unit… 🙂
One explanation could be that the moon is losing mass over time as demonstrated by the attached diagram which shows the crust has been ablated away on the Earthward face… WUWT?
http://img818.imageshack.us/img818/8302/moonschem.jpg
Richard111 says:
August 3, 2011 at 5:16 am
Nobody is forcing those people to live there. They chose to live there because it is generally very fertile soil so the can grow food they otherwise could not afford. It is the nature of the river delta that made such fertile soil available. River deltas tend to increase available land. Putting in too much control imperils those people just as much as floods and sea level rises (most unlikely scenario). Look at what happened with the River Nile flood plain after the dam controlled the flooding.
—
Forced at gun-point no… forced by poverty yes. About 50% of 162 million people living in Banladesh live below the poverty line which is $1.25 per day. Do you honestly think they have that much choice on where they live?
It’s fine for you though, living a 150m from the local habour, what do you care about millions of people being made homeless, as you say, it’s there own fault for living there after all.
With such compassion for your fellow humans I’m surprised you haven’t been nominated for a peace prize yet!
SteveE,
The people who lack compassion are those who push the “carbon” scare, and try to force their pseudo-science views on others. One result is the ethanol fiasco, which has jacked up global food prices and caused food riots from Mexico to Egypt.
About a third of the planet’s population lives on less than $2 a day. When the price of food goes up due to the CO2 scare, the result is literally starvation. The blame for those mass killings must be laid directly at the feet of those promoting CAGW alarmism. And it is not oil companies. It is people like Gore, Mann, Schmidt, the media, universities, governments… and blog commentators who blame “big oil” instead of the real culprits.
That is a straw man agreement Smokey – you are confusing policy decision with the underlying science.
Besides – the push on ethtanol was more related to oil prices than the CO2 issue. Pushing ethanol as a CO2 “fix” is dubious at best,
Crossopter says:
August 2, 2011 at 3:31 pm
In answer to a question about tidal variation over geological time, Dr Russ Evans of the British Geological Survey gives a short and interesting reply:
—————————–
Dr. Evans also writes: “Since the semi-major axis of the Moon’s orbit is 384,399 km, this means that the Earth-Moon distance is increasing by almost exactly one part in 10 billion per year. Because the gravitational force exercised by one body on another is inversely proportional to the square of the distance between them, for small changes in distance, the proportional change in force is twice the proportional change in distance. So the tidal force is decreasing by two parts in 10 billion per year.”
———————-
But the “tide generating force” is hardly an inverse square function; rather it is an inverse to the 6th power function, so that the decrease should actually be in the range of one part per billion. (Consider that for a halving of distance, gravity is quadrupled, but the relative diameter of the affected planet is now doubled a well, doubling the relative length of the gravity gradient.) Obviously such a rate of lunar recession has not been maintained for 4 billion years, and we must suppose that tidal deceleration is higher now than the norm. This idea is easily explained by continental drift: the tides of Pangea, while higher than current tides, wafted on the coasts of a single super continent. –AGF
Thank you Smokey. You said it more politely than I could. I am a pensioner and already facing the results of that pseudo compassion. 🙁
Steven E., Bangladesh is and has been subject to flooding that they welcome. They welcome it as it brings in fish etc, that they utilise. . Nothing to do with climate change. The IPCC is claiming that climate change caused by developed or industrialised countries are causing environmental damage to undeveloped countries and atolls such as Tuvalu in the Southern Pacific. Now Tuvalu is sinking, (Atolls do and are subject to storm damage and erosion from the sea they haven’t the geological stability of a coral island like Bermuda where I once lived) and part of their problems is the soil and sand removed from ocean fronts for building purposes. By American companies. I was assailed today by a green hypocrite, while studying my diploma in Organic Agricultural Production (aka as sustainable agricultural methodology). I said I did not believe in the carbon tax being forced on Australia. She (who owns two farms mind you) said the reason I didn’t believe it as it would change my standard of living but forgetting the poor people in the world? I responded I didn’t care about the ‘peasants’ in the rest of the world, I wanted to protect the ‘peasants’ and poor people in Australia! WHY DO some AGW alarmists think that all skeptics of the AGW fraud are affluent? Sustainability for sure for every country depending on the needs.
And carbon taxing will do nothing to change the climate one way or the other!
Bystander says:
“That is a straw man agreement [sic] Smokey – you are confusing policy decision with the underlying science.
Besides – the push on ethtanol was more related to oil prices than the CO2 issue. Pushing ethanol as a CO2 ‘fix’ is dubious at best,”
I am not confusing anything, and you really need to get up to speed on the ethanol issue, because you’re way behind the knowledge curve. The push to use food as fuel was based primarily on the fact that ethanol emits less “carbon.” The flaw in that argument is that ethanol has less equivalent energy than gasoline, thus more ethanol must be burned to push a vehicle the same distance. There is nothing ‘green’ about ethanol, and its mandate – specifically tied to CO2 reduction – is causing mass starvation. Further, the food riots in Egypt were easily co-opted by the Muslim Brotherhood, and now there is going to be another Iran-style Islamic theocracy in the middle east, thanks to the ethanol mandate.
The push for ethanol laws was not based on the price of oil, which always changes. Some misguided enviros made that fallacious argument, but when all costs and subsidies are taken into account, it turns out that ethanol is just as expensive as fossil fuels, if not more so.
The main problem with alarmist arguments is that they are based on emotion, not on logic. Irrational fear of a harmless and beneficial trace gas is an emotion. Fear is a strong emotion. Laws based on that fear are causing starvation. And the blame is entirely due to the climate alarmist contingent’s mendacious demonization of “carbon.”
Or perhaps there was once two moons that have since merged.. I mean collided.
http://news.yahoo.com/earth-had-two-moons-crashed-form-one-study-170201124.html
TomB says:
August 3, 2011 at 12:34 pm
“Or perhaps there was once two moons that have since merged.. I mean collided.
http://news.yahoo.com/earth-had-two-moons-crashed-form-one-study-170201124.html“
That’s a possibility, although this would not explain the moons ever expanding orbit. Need a gradual loss of mass over a long time period to explain the moon orbit paradox within the framework of our current understanding of gravity.
phlogiston says:
August 2, 2011 at 1:51 pm
That video is amazing! In all my years working on climate models I’ve never seen anything like that! – incredible how CO2 in the atmosphere can increase so sharply as to cause such a sea level rise, then abruptly fall to cause the sea level rise to be reversed – all over a 24 hour period.
Actually almost twice in that period.
Tenuc, at 207: The moon’s orbit is expanding due to tidal friction: the moon slows down the earth and the earth accelerates the moon. Simple Newtonian physics. No need to invoke relativistic physics or a hypothetical moon. –AGF
Smokey says:
August 3, 2011 at 9:16 am
Seriously Smokey, the price of oil has increased ~50% in the last 12 months, that’s not because of climate alarmism or people like Gore, Mann, Schmidt etc as you say. Carbon taxes has not increased the price, it’s because of supply and demand and the peceived risk to that supply.
Your statement is the alarmism in that a carbon tax is going to cause mass starvation.
A G Foster says:
August 3, 2011 at 3:46 pm
“Tenuc, at 207: The moon’s orbit is expanding due to tidal friction: the moon slows down the earth and the earth accelerates the moon. Simple Newtonian physics. No need to invoke relativistic physics or a hypothetical moon. –AGF”
Sorry, but that’s rubbish! If tidal friction operates then this would simply lead to a more eccentric moon orbit, with the Earth moon system gradually falling towards the sun. The paradox is real.
SteveE says:
“… the price of oil has increased ~50% in the last 12 months…”
In fact, your entire post above is a textbook example of a strawman argument. You really need to think about what I wrote, instead of presuming I wrote things I that didn’t. As Willis often says: quote my words, then we can discuss them.
The law mandating ethanol wasn’t passed in the last 12 months, so you’re arguing with yourself. I pointed out that the price of fossil fuels fluctuates. I wrote nothing about a carbon tax. I explained that the mandate for ethanol was a cause of the rising cost of food worldwide and the concomitant food riots. I explained that ethanol is as expensive as fossil fuel when extraneous costs and subsidies are taken into account. I explained that ethanol contains less energy than gasoline, and that it emits less CO2, which was widely touted at the time as a justification for mandating its use. All these statements are easily verifiable. But if you want to set up a strawman argument and then debate it, by all means, go ahead. Just don’t presume that you’re disputing something I wrote.
Tenuc says:
August 4, 2011 at 9:46 am
A G Foster says:
August 3, 2011 at 3:46 pm
“Tenuc, at 207: The moon’s orbit is expanding due to tidal friction: the moon slows down the earth and the earth accelerates the moon. Simple Newtonian physics. No need to invoke relativistic physics or a hypothetical moon. –AGF”
Sorry, but that’s rubbish! If tidal friction operates then this would simply lead to a more eccentric moon orbit, with the Earth moon system gradually falling towards the sun. The paradox is real.
————————————————-
Tenuc, do you believe the moon causes the tides or don’t you? (Newton did; Galileo didn’t.)
Do you believe the earth is decelerating or don’t you? (Google LOD or “leap second.”)
What do you think is making the earth slow down?
Do you believe in Newtonian physics, like “conservation of angular momentum”?
Do you think it’s possible for the moon to slow down the earth without raising the moon’s orbit?
You are arguing against very elementary physics. The only thing you have right is that tidal torque increases lunar eccentricity–George Dawin knew that. And that’s why the moon’s orbit is so eccentric. You need to go back to school before you try to argue here. Some of the folks here actually know what they’re talking about, at least some of the time. –AGF
FYI -“Arctic ‘Tipping Point’ May Not Be Reached”
http://www.bbc.co.uk/news/science-environment-14408930
Well Golly Geeeeeee Wiz and Shazzzzzzzzzzzam!!