Are Man Made Islands Accountable For Raising Our Sea Levels?

One needs to subtract dredging and both seawater and a percentage of the mud injection into gas and oil wells.

Doesn't most seaport dredging just pick up the material in one water way and take it out and dump it somewhere else?

As far as I know only river and lake dredging brings the material on land. Most sea dredging material is largely useless for any land filling purposes due to the high salt content other than putting sand back on beaches and even then thats more just putting something back that washed away. No major net changes for the volumes moved.

Years ago, I lived in Del Mar. We would go to the beach and watch the offshore dredging ships pump sand to the beach. They did this from Pacific Beach all the way north to Encinitas (maybe even further north?). What was sad to see was the amount of sea life dumped on the beach. Lots of sea shells (and creatures inside) partially crushed from the pumps. Surprisingly, I didn't see much other sea life. Maybe a small octopus or fish here or there, but not much.

This was done in 2000-2001. Recently, I drove by Del Mar and the sand seems to have washed back into the ocean.

Also, in the late 80's to early 90's, I worked in Port Hueneme. They were dredging the harbor area. I don't recall where they dumped the material - maybe back in the ocean outside the harbor? I do remember them telling me that they need to do this every so many years, or the Navy ships won't be able to dock.

Probably about as much as dropping a quarter into a tub of bath water.

What about all that cosmic dust as well....? What about seaweed growth and expanding fish populations...? Volcanic eruptions...? Moon's gravitational pull increasing...? Alien populations building underwater habitat's....? Maybe the land is shrinking due to all the oil and gas being pumped out....What about all the ships that have sank and all the garbage thrown in the sea, and the artificial reef's.....

Photo op with alien pod dweller's...

0.3 X 10¯35 % max. The British are giving some back too.

I'd say about 1% of the amount that melting sea ice is raising the level.

Or, is that just more lies being spread by Al Gore?

Well you know the sun is millions of degrees right?

Mostly I was just curious about the validity of the concept of man made islands adding up to much in realistic volumes of oceanic displacement.

However that said Japan knocked down part of a mountain to get their 21+ million cubic meters of fill material to make their Kansai Airport which is apparently still sinking.

http://en.wikipedia.org/wiki/Kansai_International_Airport

In the worlds most monumental act of arrogance and stupidity, dubai did this:

islands were intended as the ultimate luxury possession, even for Dubai.

The low-lying islands represent a vague shape out to sea when viewed from Dubai's beaches Photo: AFP/GETTY

Sand was dredged from the ocean and the idiots never considered that it would all wash back where it came from. How much water's in the worlds oceans? I don't think a paultry 21+ million cubic meters of dirt will raise it up much.

I read a news article about the ice shelf in the Arctic shrinking, but the Antarctic shelf as it turns out, is growing. That is why you don't read or hear about global warming much now.

For another interesting read do a little research into to the Ozone layer hole.

Odd thing is its not a hole but a seasonal thin spot, ~100 DU with 300 - 400+ DU normal, that comes and goes very predictably with the annual seasonal changes and apparently has been doing so since the very first Ozone layer measurements were ever done.

It's almost like it was probably always there to begin with.

I doubt we have exceeded the amount of solids deposited in the oceans by all the major rivers in the world....but then you never know.... humans have a history of being rather destructive on a relatively large scale far out of proportion when compared to our actual size and knowledge.

Yes. The ozone layer was also thought to be receding. True to the conspiratorial clans report as result of the CFC's we were using. Again a fiction well told.

I thought sea rise was due to thermal expansion, you know, because of Global Warming....




http://wattsupwiththat.com/2013/09/25/national-geographic-rising-sea-level-prophecycause-for-concern-or-absurd-fairytale/

None as it's not cost effective to haul soil from the land to deposit. When there is plenty under the water. Most of these projects start with the need to clear harbors and dreg channels for shipping. What to do with these spoils is the idea. Build land mass sounds like a good idea. Since most of these spoils came from the land surface to begin with. Like your river silt.

All the soil on the surface is flowing down hill heading to the ocean. Not just the silt in the river. So and attempt to place the soil above the water lowers it's level.

The engineering project and feat is how to keep it there. If you just pile it up is flows back down in a short time to where you got it.

Like this Hart-Miller island project in the Chesapeake Bay. Spoils are from the Baltimore Harbor. The land part of the state's park system.

The effect is probably very small. Knowing what the actual contribution to any effect over time becomes very complicated once you begin to consider things like rebound to tectonic isostasy or considerations geologic eustacy.

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It has been suggested that if all the ice were to melt off Greenland, that the local sea level would be lower than current....and not just after there was sufficient time for rebound, but immediately because without the ice, there would be less gravity pulling the sea levels higher in the surrounding areas.

Short answer is NO I dont think so!

Long answer is hidden in all the replys.

Buildind an island that pushes on the seafloor might even create more space for water than it took to displace in the first place (more so if material from the sea is taken to build the island)

Rivers still will put more silt into the ocean than humans will ever do with artificial islands. Are we concerned about this?

This is just the same question if humans contribute to a warming on Earth.

We will never deny that we have no impact whatsoever, everyhting is related, but how big or minuscle the impact is is the question. I tend to think we have a rather minuscle impact and whoever wants to make someone accountable for it drives his own agenda.

"We will never deny that we have no impact whatsoever, everyhting is related, but how big or minuscle the impact is is the question. I tend to think we have a rather minuscle impact and whoever wants to make someone accountable for it drives his own agenda."

I can live with that answer!

Billions and Billions!

Seriously, it's a drop in the bucket.

Sorry, I couldn't help myself.

Dredging rivermouths to fill low lying areas & using sand for buildings is good. Also instead of making islands building raised platforms near the sea for buildings,kids park etc is better.

Small nations like Singapore & UAE can build structures on raised platform in the sea for homes,offices,shopping malls,schools,parks etc etc

I can't add anything intelligent to this discussion. I agree... No.

Most certainly, there is nowhere near as much ocean water volume that is displaced by man-made islands as there is by the volume of sedimentary run-off material that is washed down rivers and streams, past coastlines, worldwide, each year...

Such material is just not accurately measured, yet, to put a ''hard number'' on the amount of ocean water volume lost to such granular material (in-flow), yet...

'....to put a ''hard number'' on the amount of ocean water volume lost to such granular material (in-flow)....'

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...'Zero'. Zero is the amount of ocean water volume lost to granular in-flow. The density of the ocean water is not significantly increased by the non-soluble granular in-flow and any increase in density from any soluble in-flow is insufficient to offset anything beyond the mass of the inflow, so the volume is not shrinking or otherwise being lost to anywhere

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Moreover, as the rivers transport erosion products away from the land mass, other forces oppose attempts to totally submerge the land masses. As mass is transported away, less gravity pulls the water toward the land ass and the lightened continent can experience an upward movement similar to post glacial rebound. even as sediment settles out to sea along with the carbonates transformed from CO2 by so much tiny sea life, it tends to be less dense than the sea floor crust, and as the crust is recycled into subduction zones, that less dense material collects together like a giant buoyant sea of all life's garbage. Our refuse islands aren't at risk of sinking into the sea.

The cumulative effect of granular material in-flow might not have a noticeable impact to the planetary water level in a day, or a week, or a month, or even a year. But the rivers and streams just keep on filling-in the ocean decade after decade after decade, whether we admit it or not. So, any man-made islands can only accelerate such a process...

In any case, maybe NOAA can quantify said process?...

'...whether we admit it or not...'

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It isn't a matter of accepting or denying. With very localized exceptions in delta regions resting on already elevated continental shelf, inflow of sediment has not filled in the oceans in the few billion years the planet has had oceans. There is no indication that it is going to begin playing a dominant role going forward.

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Changes from sea floor subduction, sea floor spreading, and continental collision dwarf any changes related to the addition of erosion products. This is unlikely to change until the core of the planet has cooled sufficiently eliminate most tectonic motion, but by that time, rising sea level would be a very small worry in light of the loss of the Earth's protective magnetic field.

Please identify the exact location of where I used the word ''dominant'' in any of my replies...

If you don't like dominant, allow me to change my statement. This is even more encompassing;

'....There is no indication that it is going to begin playing a significant role going forward....'

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The original comment and this upgraded version are in response to what you implied in your earlier statement;

"...But the rivers and streams just keep on filling-in the ocean decade after decade after decade, whether we admit it or not...."

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This seems pretty clearly to imply that the inflow of sediment is causing or will cause a significant general rise in sea level. If this was not your intention and you were only describing insignificant changes that will not have noticable effects, then we have no disagreement. If on the other hand, you are suggesting otherwise, a decent reference supporting that assertion could show me the error in my disbelief.

Due over use of groundwater without replenishments,the evaporated water become rain and flows to the sea thus raising sea level,ultimately there will be very low groundwater.

In mid-east India etc too much of groundwater is used but in certain parts of India rainwater harvesting is practiced to save ground water.

Hope the other forum says the same as here. The sea rise in mm will be so far out we don't have enough zeros to place after the decimal

What difference, at this point, does it make?

Are you related to russ123?