Wouldn't melting ice = lower sea levels ?

Called as thermal expansion, remember that global warming also heats oceans.
(excessive heat also seems to kills corals and coral reefs are very diverse ecosystems)

Originally posted by Whiskey Jack
Try an experiment. Run down to Petco, or your local equivalent. Purchase a bag full of saltwater fish...

I would prefer putting mouthpieces of corporationism to one building whose ventilation system would took air from car exhausts and factory pipes and water woulde be taken from sewers of factories.

Melting of floating icebergs would have no effect on sea levels. Although ice takes up more volume than water, part of the iceberg is above the water, the net effect is zero change in displacement.

Melting of continental glaciers would dump a lot of water into the oceans, causing a rise in sea levels.

Originally posted by Dr Love
So if something caused the ice to melt very quickly, and the isostatic rebound didn't happen at the same rate as the ice melting,

THe rebound will definitly not happen at the same rate as the ice melting. Like b.o.b noted, hudson bay is undergoing rebound. Most of the northeast US is also undergoing this from the last ice age. When there is an earthquake in NY, for example, its usually related to this.

sardion2000
It would also disrupt the various currents that transport heat to Europe,

I was under the impression that the major concern of ocean salinity is with respect to the Mid Ocean current, which has nothing to do with temperature currents? Undoubtedly, melting all the ice at the poles would have other affects.

battleofbatoche
The major rivers in India have salt water sharks swimming in them, so do river systems connected to the ocean in America. There have been documented cases of Great whites swimming in lakes connected to the ocean by rivers

Interestingly, sharks are a group of species that are thought to have been derived from freshwater species. Regardless, if the salty oceans became very unsalty, there'd be a lot of dead organisms, fish and otherwise. Massive extinction tho, probably not.


Either way, there have been periods of very high sea levels in the earths past and these are associated with a lack of ice at the poles. Melt all the polar ice and you have a rise in sea levels. Have a huge, a really huge, peice of antartic ice fall off the shelf and into the oceans, and perhaps you'd have an increase in sea levels too. At the global scale, massive melting of ice leads to a rise in sea levels. Melting of icebergs already in the ocean apparently just causes a chang in salinity.

Wellllll...... Actually if the sea level rises then areas like the black sea and low lying salt flats near coastal areas will release their salt content into the ocean and this will compensate for the freshwater from the ice burgs. The Earth doesn't operate on a human time scale.

AAARRRRRRRGGGGG!!!!!!!!

NO NO NO NO NO NO!


Floating ice DOES NOT change the water level when it melts.

(njspeed’s experiment does not count, because all of the ice was not floating freely.)

When an object is less put into water it displaces the water equal to its volume. If the object is less dense then water, then it will only displace the amount of water equal to its own weight.

lets say you have an ice cube that weighs 100 grams Now the density of ice is 1.07 cc/gram. Therefore the ice cube will be 107 ccs in volume. Now water is about 1 cc / gram. Therefore a 100 gram volume of water will equal 100 ccs.

Thus the ice cube will sink into the water until 100 ccs are in the water, the remaining 7 ccs will “float” above the water. When the ice melts, you will have 100 grams of water in 100 ccs. The volume of the melted ice will equal the volume of the water already displaced. Thus there will be no net change in the water level.



edit: oops, didn't see dj's post. carry on.


[edit on 4-3-2005 by HowardRoark]

take a glass and fill it a 1/2 full with water, now take a large chunk of ice (like a clump of ice from a bag if ice, etc) and drop it into the glass so that a portion of it is above the "waterline" mark the waterline and take the glass outside in the sun. Wait until ice is melted and observe waterline... Did it go up ???

Or was the total displacement of the icecube "clump" already accounted for in the first waterline marker ?????

The waterline raised from 1/2 up to X when you put in the ice cube clump, therefore when the ice melts there will be no change in the new waterline as the increase in volume was already accounted for by the displacement of the total ice cube clump. Not to mention that it is also possibly that the waterline would drop after the heat exchange and melting by the sun causes a small portion of the water to turn to vapor and evaporate.

Therefore the only risk in the world ocean in rising is if all the landlocked permafrost was to melt off and into the sea. And the chances of that happening without simultaneously causing severe tropical storms which will suck up the extra water volume into the air only to return it back to the ground and start a new chilling cycle as the water vapor becomes a great heat exchanger in the atmosphere and thus we will begin a new cold cycle on the planet.

This has happend probably thousands of times over the life of the planet. Mild cold, moderate, warm, thermal cap, cooling, mild cold, artic cooling, mild warming, moderate, cooling, moderate, mild cold, moderate, warm, thermal cap, cooling... and repeat

Now lets says we used X volume of the world oceans by converting the ocean water and splitting it into energy and through thermal reduction we begin to lower the total volume of sea water, we could damage the natural warm/cooling cycle of the planet and adding in the pollution and ozone damage we could bring the planet into a phase that there could be no natural recovery from.

Just a thought.

Originally posted by BattleofBatoche
Wellllll...... Actually if the sea level rises then areas like the black sea and low lying salt flats near coastal areas will release their salt content into the ocean and this will compensate for the freshwater from the ice burgs.

An interesting idea, but I sincerely doubt that there is enough salt in the dirt in near shore environments to compensate.

``

all good points,

consider that the water no longer being trapped as ice would be entering
the weather/water/conveyor system

the greater worldwide rainfall would find that more water will be trapped in
all those engineered lakes, ponds, canals, resevoirs, found in every village,
town, city, county in america and to a somewhat lesser degree
in the rest of the world as well.

more rainfall should mean new and unexpected bodies of water pooling in
valleys or canyons or depressions or in presently dry 'carolina bays' etc.

more sunlight is then reflected from these new, mirrorlike pools of water,
together with all the modern engineered bodies of water which have been
constructed since the Industrial Revolution:

to address mans water needs for irrigations, canal& river transport,
city population needs, energy production, even aestetics, etc etc

i might suggest, mans' terra-forming with-for-by water has contributed
more to the hypothesised 'global warming' than the green-house gasses
model.

BattleofBatoch you made some very interesting and well argumented points, should we just turn up the heat and allow Greenland to melt etc ?

In your view, in a global melting scenario, wich countries would benefit and who might find themselves affected negatively?


[edit on 5-3-2005 by Countermeasures]

I agree that the melting ice would cause no difference to sea levels. but then the problems come, as with global temperatures "rising" it could then warm the seas, causing 'thermal expansion'.
With a warmer atmosphere it causes the sea to warm up, and hence expand, due to the fact that substances, when heated, expand (to put it simply). therefore causing sea levels to rise. this however is a very slow process, to to the fact that there is massive amounts of water in the oceans and that it has a high heat specific capacity. so that means that it would take an extremely long time for the sea temperature to 'catch up' with the atmosphere. in shorter time scale, only the surface water is heated from direct contact with the atmosphere. the deep water will take much much longer to warm.

didnt look to see if anyone has written about this yet, but thought id put it out there anyway. peace.

EVERYONE FORGETS THAT FACT THAT LIKE MORE THEN 50 PERCENT OF THE ICE IS ON LAND!!!!!!!!!!!!!!!!!! gar.

Everyone forgets that the ocean already contains 97% of all water on earth. The remainder is literally a drop in the bucket.

The world ocean contains about 97 percent of all the water on the earth. Most of the remaining water is frozen in glaciers and icecaps. The rest is in lakes and rivers, underground, and in the air (Eliav.)

Salinity vanishing? Are you serious? Not even with every drop of the remaining 3%.

Every natural element can be found in the waters of the ocean. But the ocean is especially known for its salts. Seawater contains, on the average, about 31/2 percent salts. Six elements account for 99 percent of the ocean's salinity. They are chloride, sodium, sulfur, magnesium, calcium, and potassium. Most of the salty material in the sea consists of the compound sodium chloride, which is commonly known as table salt (Eliav, Weiss.)

Nice to get a more detailed picture on topic.
I like it !

I've talked to people who have tried to keep salt water fish alive at home. it doesn't even have to be pure fresh water, if what they say is right. All that is needed is a little change in the ph level for them to die...

The fish living in areas where the situation could become reality, will probably be more able to adept to altering conditions.
The fish that died are already highly specialised, being able to live in captivity. The more specialised a species is, the less adaptable it is to adept even more. Not to mention the shock the fish had to experience and the time needed for a change in ocean salinity. If it even is enough to be noticed.
Deny ignorance. Said it before.

Salt water wil not flow back into the oceans from the black sea.
Salt water is heavier then fresh water and it just happens to be confronted with a fresher sea above it to escape the bowl it's in
.

The waterline raised from 1/2 up to X when you put in the ice cube clump, therefore when the ice melts there will be no change in the new waterline as the increase in volume was already accounted for by the displacement of the total ice cube clump. Not to mention that it is also possibly that the waterline would drop after the heat exchange and melting by the sun causes a small portion of the water to turn to vapor and evaporate.

This will probably also be a result. The fresh water brings a more dangerous and bigger scenario to be possible.
Do to the fresh water flowing and raining at the North Pole. The usuall sinking of salt water will be a problem. The water will not sink when there is to much fresh water added to the salt water.
The reason it sinks at the poll is because the salty warm water cools down. As the salt water start to sink because it gets cools down and warm water flows to the survice. Resulting in a circulation.Kept going with the sinking salty cooling water and at the equator the warming up.
If the salinty will drop far enough, the water won't sink and the oceanic transport of warm water will come to a standstill.

The gulf stream keeps Europe warm providing the heat for the air above it staying warm. If it failed it wil get as cold as Canada . All the way to spain will temprature plummet.

This event could take plac in less then a decade. Europe will get as cold as during the last ice age.

The positive side of this is, global warming will stop do to the amount of ice and snow covering Europe an the Atlantic. Cooling the Earth down by reflecting it's heat.

Well.. it's a possibility. It's based on a lot of evidence. From analyzing deep ice core data. Looking to what the climate was like in history. The ice in prisons tiny parts of the atmosphere in air bubbles getting stuck in it.
Looking back almost 100.000 years back in time. As far as the oldest ice lets us.

I think it's amazing !! Every original theory to explain anything on Earth. They all had to be rewritten again and again. Because there are still discoveries being made, altering what wil happen to be final.

Every time wiping the arrogance from a lot of faces who knew it all.

Never a reason to be bored on our wonderful planet.

There are actually many factors to be considered when discussing the effect a temperature increase would have on ocean levels:

• Melting ice already floating in water would have a zero effect on water levels due to the buoyancy principle. This has already been mentioned.
  
  
• Ice on land would have some effect on ocean levels as it melted and the water drained into the ocean.
  
  
• The land underneath the glaciers would also, as previously mentioned, rise in response to the decreased weight on it. This would decrease ocean levels.
  
  
• Increasing temperatures would result in increased water vapor levels in the atmosphere and would serve to decrease ocean levels.
  
  
• There would be some slight thermal expansion of the water due to a temperature increase. This would give a minimal ocean level rise.

Added all together, the result is we simply have no real idea what a given temperature increase would do to ocean levels. The commonly propagandized catastrophic ocean level increases take into effect none of the above except the effect of melting land-based ice, and therefore are anything but accurate. We have also seen no evidence of oceanic level changes since the whole Global Warming concern was introduced, now 20 years ago? Coastal homes and condos are still the same distance from the shore.

As to salinity changes, these would only be localized at best. The amount of salt in the oceans is fairly constant (except for the steady increase form incoming 'fresh' water laden with minerals) and will not change overall unless the actual volume of the water in the oceans changes. Since this change would by definition cause an ocean level change, which has not been observed, there is no concern related to overall ocean salinity levels. It is possible that small areas would see a decrease in salinity and also possible that this could cause current shifts, but both of these phenomenon would be temporary. Dissipation will restore the balance in a short time frame.

TheRedneck

reply to post by TheRedneck


Well... You make it better understandable then then I ever could.
Bit I still want to criticize some.

The salinity of only small regional areas.
The theory what predicts a hold or total shut down of the Atlantic conveyor belt. Stopping the flow of heat.
It included a lot of what you said. I'm not sure if their is something missing. I didn't study the subject.
The extra fresh water believed to be needed for making the salinity not able to sink, is far surpassed by the amount of water flowing in the arctic sea. By rivers fed on more rain and melting permafrost. Along the extra downfall of water in the area itself. What remains uncertain is the time needed for the water stops sinking. Also the Greenland ice shelf is a uncertainty. It is melting faster but no knowledge if it melts fast enough to reach the deadline.

If it has stopped, you are right about the short time frame it could be reversed to what it is know.
However they don't know how and if the conveyor belt needs or takes t restart.
If there has been a big enough increase of frozen and snow covered Earth. The reflection of heat can still cause the Earth stay cold for 1000 years before it starts getting warmer.

I definitely don't know for sure and science never knows for sure, always staying sceptic. They probably make a better guess then me.

I'm only like a little kid in a candy store when it comes to these topics.

Originally posted by Gazrok

Only if the icebergs were floating. If say a landlocked iceshelf were to melt and drain into the ocean it would decrease salinity and add volume.

This pretty much hits upon the crux of the issue...

Also, say you have a huge piece of ice floating in the water. (thus displacing a certain amount of water). Now, a large piece from the top breaks off and then melts into the sea. The iceberg is still displacing about the same amount of water, but the part that broke off is now adding to the water level. Sure, if ALL the floating ice melted, it wouldn't be an issue, but it's the ice shelves breaking off that are the real issue....

If the piece at the tope that was sticking out melted away or broke off and fell into the ocean then the iceberg would raise out of the water again as it's weight changed. It's wouldn't magically stay completely submerged and wouldn't displace any extra water. That would be impossible.