We can't see gas in the core samples we collected on our expedition, but we do see examples of ash and pumice. I think pumice is especially cool because it is made when magma from inside the earth gets puffed up with gas, kind of like when you stick a straw in soapy water and blow. The magma cools down really fast and traps those bubbles inside.
All the trapped bubbles in pumice make it really light. It's actually so light that when underwater volcanoes (like the ones we studied on our expedition) spit out pumice, it can float on top of the ocean! Have you ever heard of a rock that floats? When enough pumice floats in the ocean, it can create problems for ships. They can't sail through sections of the ocean that are filled with pumice because it gets sucked into their engines. Luckily all the pumice we saw on our trip was very old and was buried underground in our core samples.
2. Ships move six different ways!
When you drive your car, you can move in two different ways. Forwards and backwards, or left and right.
Ships have six types of motion! Like cars, they can move forward, backward, and side to side. They can also move up and down in the waves. That's called heave. The nose of the ship can tip up and down, like a teeter-totter, in a motion called pitch. And the ship can sway side to side in a motion called roll, kind of like rocking a baby cradle back and forth. The last kind of special ship motion is called yaw, and it is when the ship spins back and forth around its center, like swiveling on a desk chair.
