Originally Posted by GBRaul
Actually the water level would stay the same. According to Archimedes' principle of floatation (I think it's his principle), 90m kg of displaced water would result in an upthrust that would hold up 90m kg of ice. Thus the ice berg is actually 90m kg heavy so it would generate 90m kg of water when melted. So the space taken up by the ice at first would just be filled up exactly by the water resulting from the melted iceberg. However, due to impurities, there might be a slight increase/drop as opposed to the expected constant sea level.