I never knew chilly, heavier water could do this:
The deep seas are a vast reservoir of carbon dioxide, dissolved under pressure, but the chilly and hence heavy water from the disappearing bergs – helped by the Fleuve and its fellows – sank to the bottom and pushed that ancient reserve of trapped carbon towards the surface. Gas bubbled out and entered the air, pushing onwards the wave of warming. Within a couple of centuries the glaciers began their precipitate retreat, the oceans rose by tens of metres, and we were in the modern world.
From this mythic article in the Telegraph, written by a professor of Genetics.
That water sure has to sink a long way, and as we all know, cold and warm water don’t mix. /sarc
Of course, some simple grade school science on water density can tell us a lot too. From Steve Spangler’s Science:
The Floating Egg
It’s so simple and amazing. A raw egg will float in very salty water but will sink in plain tap water. Why? Salt water is more dense than regular water. You’ll need to make a very saturated salt solution by dissolving roughly 4 tablespoons of salt in about 2 cups of water. Use pickling or Kosher salt to make a clear salt solution. Table salt may be used, but the solution will be somewhat cloudy due to the additives used to make the salt free-flowing.
Fill a glass half full with the salt water. Slowly add plain water by pouring it down the sides of the glass, being careful not to mix the two liquids. Gently drop the egg into the water and watch as it sinks through the plain water, only to abruptly stop when it hits the salt water. The egg floats on the top layer of the salt water.
Also, for those that might argue that berg meltwater just above freezing is more dense because it is colder, there is a curious thing that happens at 4C, as outlined in this Iowa State course:
“In regions where precipitation is high, such as the Intertropical Convergence Zone in the central Pacific Ocean shown in the lecture on Atmospheric Structure and Circulation (figure 9), fresh-water rain will ride on top of the saline ocean water. Similarly melting ice in polar regions will be less dense than nearby ocean water of temperature 4 oC because of its lower temperature and lack of salt.”
And Verity Jones adds this in comments:
“Arctic sea [melt] ice plays a critical and hitherto unknown role in the removal of the greenhouse gas, carbon dioxide (CO2)”
“…in this study, the researchers have found that sea ice itself plays an important role in CO2 capture, effectively pumping this potent greenhouse gas out of the atmosphere. As sea ice forms, it rejects brine, rich in inorganic carbon compounds (derived from atmospheric CO2), into the underlying seawater, a process further stimulated by carbonate precipitation within the sea ice. The summer sea ice melt liberates water which is strongly depleted in CO2. The very low concentration of CO2 in this surface water then drives the extraordinary uptake of CO2 from the atmosphere.”
h/t to Pablo ex pat who quips: “Geomythology is a new science to rival Climomythology”