Swiss cheese, bubble gum, Rice Krispies and rocks all have one thing in common. Bubbles. We can see the molds of bubbles in Swiss cheese and if we look closely at Rice Krispies, the dried cereal is full of tiny bubbles.

Indeed, bubbles are important in many different fields of science, including chemical engineering, material science, fluid mechanics and geology. When we pull up the rocks from the seafloor we are looking for, among many things, vesicles - bubbles of gas trapped in the lava. Bubbles in volcanic rock are also thought to contain gases from deep in the Earth.

“That’s how the ocean was formed - from out-gassing of the interior of the Earth,” Mark Kurz says. The gases are mostly carbon dioxide (CO2) mixed with some water.

The hot temperatures of Earth’s interior melt solid parts of the mantle to form magma. The added impurities of water and carbon dioxide lower the melting temperature of a solid, the same way as added salt lowers the temperature of ice.

When the hot magma touches the cold seawater, the surface cools so fast, it forms glass. The glass in our submarine lava rock samples appears as a shiny black exterior coating. The quick formation of glass traps some of the gases from the magma. A tiny amount of helium is also found inside vesicles in the glassy coating.

Evaluating the helium trapped inside vesicles in submarine lava helps us understand the origin of magma in the mantle. Mark Kurz will measure the helium back in his laboratory, where he and Josh Curtice will either crush or melt the glass to release the trapped gases. We also hope to use helium measurements to date the lava flows, which can then tell us the age of the features in the MR1 sonar maps we have made.

It’s an experiment not unlike stomping or melting the protective bubble wrap found inside packages, only we collect and analyze the “air” that’s released. On the ship, we are very careful to collect even the smallest pieces of glass that we dredge from the seafloor. A piece no bigger than a fingernail may have a million years of stories to tell.

Dive and Discover Water Word Puzzle [Click here for a printable version of Dive and Discover Water Word #1] Check back tomorrow for the solution.

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