12 November 2015 The Check Out Dive

Journal

Research Update

Our research team is preparing to collect samples. If all goes well, we will head out to Cape Bird tomorrow to collect sediment samples at a control site. This is especially exciting since Cape Bird is near an Adelie penguin rookery. To prepare, Steve Sweet labeled sediment jars, Andrew Klein used a computer program to identify our sampling locations and Carl Green entered latitude and longitude coordinates into the GPSA Global Positioning System (GPS) is a satellite-based navigation system used to track the location or position of objects on the Earth’s surface. which we will use to find our sampling sites.

The Check Out Dive

Today, Terry Palmer, the benthic ecologist on our team, completed a check out dive with the United States Antarctic Program (USAP(abbreviation) United States Antarctic Program) dive supervisors. A check out dive is a short dive that ensures the diver is prepared for diving under the sea ice. Veteran divers made sure Terry was safe and ready for future dives.

Divers in dive hole — Clockwise from top, Steve Rupp, Terry Palmer, John Heime and Brenda Konar sit in the dive hole before putting on their masks and diving under the sea ice.

Insulation for the Frigid Water

Before Terry gets into the ice cold water, he has to make sure he is dressed properly. The water in McMurdo Sound is around -1.8 degrees Celsius. Water freezes at 0 degrees Celsius. Terry needs to make sure he is warm enough while he is underwater, so he wears insulated layers under his dive suit.

Terry in the dive hut — Terry Palmer shows off the thick insulated layer he wears under his dive suit to stay warm.

Critical Thinking

Why is the water in McMurdo Sound colder than the temperature of freezing fresh water (ice)? Write your thoughts in the "Ask the Team" section.

A Seal in the Hole

The check out dive occurs in the fishing hut, a heated room that sits on top of a diving hole near McMurdo Station. When we arrived at the dive hut, a Weddell Seal came up to say hello.

Steve and the Seal — Steve Rupp says hello to a Weddell Seal who came up to take a breath before swimming back under the sea ice.

The Antarctic Treaty's Protocol on Environmental Protection requires humans not to interfere with animals in Antarctica unless it is for approved research. If the seal had decided to stay in the dive hole, we would have had to wait for it to leave before Terry could do his check out dive. Luckily the seal swam away after poking his head above water for a moment.

Looking Out from the Ob Tube

While the divers conduct Terry's check out dive, Carl Green and I took turns watching them from the observation tube, or "Ob Tube." The Ob tube is a giant cylinder that sits under the sea ice. You can climb down into the tube and sit in a small room with windows to look out into the sea. If you are lucky, you can see or hear seals and other interesting organisms swimming around.

Michelle and the Ob Tube — Michelle Brown looks down into the Observation Tube.

Steve and Terry and the Ob Tube — Steve Rupp, at left, and Terry Palmer, at right, swim up to the Ob Tube to say hello to Michelle Brown. Photo courtesy of John Heine.

It is magical to be in the Ob Tube. You can hear the strange sounds of seals and watch curious, tiny sea-creatures float by. It is especially exciting to see Terry and Steve through the window!

A Diver's Perspective

Although you can see many organisms as they float by, divers get to see the organisms on the sea floor. A veteran ice diver, John Heine, took the pictures below of sea life during the check out dive.