Does icebergs melting cause a rise in sea level?

Question

To have a better chance of getting the best answer, defend your answer.

Answer 1

Yes, melting icebergs cause a rise in sea level, because the melted ice becomes water. Many people are also worried because this rising sea level can flood many small islands out at sea...

Answer 2

yes, because then that melted ice adds to the water in our ocean.

Answer 3

Finally someone with a bit of sense!  I was going to answer the way mnrlboy answered, but he beat me to it!

Answer 4

Jcool,

This is actually a very common misconception. It turns out that melting icebergs do NOT cause a rise in sea level. Here's why:

Icebergs are made form ice that is essentially ALREADY PART OF THE OCEAN. To start out with, 10% of the ice is above the water, and the other 90% is below the water. When the iceberg melts, the 10% that was above sea level is added to the ocean.... but that's not ALL that happens! The 90% that was below water and made up "part" of the ocean will DECREASE it's volume because water is more dense than ice. This effect exactly offsets the addition of the water from the top of the iceberg, and the net effect is that the volume of the ocean, and hence sea level, does not change at all.

Those who say that it will increase sea level are making an educated guess based on what seems intuitively reasonable to them, which there's nothing wrong with, but they don't have a thorough enough understanding of the physics of the situation.