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Popping Rocks

June 30, 2017

A sample of seafloor lava, magnified 100 times, shows tiny, silver-colored glass vesicles trapped within the rock. The vesicles contain gases from deep inside the Earth, where magma forms before it erupts at the seafloor. In 2016, a WHOI expedition, sponsored by the National Science Foundation,  used the autonomous underwater vehicle Sentry and the human-occupied submersible Alvin to find and collect samples of these popping rocks. They are so-named because when brought to the surface and no longer under deep-sea pressure, the gases escape with an audible pop. The rocks hold clues that could shed light on fundamental chemical and geological processes occurring deep within the Earth. (Photo by Mark Kurz, Woods Hole Oceanographic Institution)