May 8, 2021: Shrunken Cups
Image courtesy of Exploring Carolina Canyons expedition. Download larger version (jpg, 5.7 MB).
It is difficult to imagine the pressure deep in the ocean. Just as there is a change in air pressure when one goes up a mountain or rides an elevator in a tall building, the water pressure changes as one dives downward in the ocean. At the ocean’s surface, air pressure is about 14.7 pounds per square inch (or one atmosphere). On average, the pressure increases about one atmosphere for every 100 meters (328 feet) you dive.
One way to demonstrate the change in pressure with depth is to attach a Styrofoam cup to a piece of sampling equipment and send it down to the bottom of the ocean. As the cup descends, the air is squeezed out of the Styrofoam and the cup shrinks. The deeper it goes, the smaller the cup gets.
During the Exploring Carolina Canyons expedition, students were invited to decorate Styrofoam cups with permanent markers that were attached to science equipment and sent deep below the ocean surface. These cups, decorated by students from Millhopper Montessori School in Gainesville, Florida, are beside an original cup showing the difference in size.
From: Under Pressure: Shrinking Styrofoam Cups in the Deep Sea.