Ask Theodore
So, Theodore's next question has come from a large number of people. It goes something like this:
Dear Theodore,
How deep do the divers go? When you drill the dive hole, how do you know that it won't be too deep for the divers to get to the bottom?
Great question! This one isn't so much of an experiment as a "How To", so we'll write it out like the steps in a Procedure. A procedure are the steps in a process or experiment that tell you the order in which to do things. Think about making your favorite sandwich, there are certain things that you have to do in a certain order (like get the bread out first!). So, here's the procedure for checking the water depth in McMurdo Sound.
Step 1
Assess the risk! Theodore knows it's always safety first. The divers aren't supposed to go deeper than 130 feet. There are a number of reasons for this, but let's just say that there's a lot less potential for injury when the divers stay shallower than 130 feet. So, we're looking for locations where the ocean bottom is 130 feet or less.
The team has appointed Theodore as our Risk Assessment Expert. He even has a helpful chart that he got at training.
Step 2
Next, Theodore assembles the team and the necessary materials. For checking depth, we need to drill a small hole in the ice and we need a weighted measuring tape.
Theodore organizes the team's materials, including the Kovack drill, GPS, and measuring tape.
Step 3
Locate the desired spot. We use GPS (Global Positioning System) to locate the potential dive site. Then, we need to drill. The drill is assembled in three foot segments, called "flights".
Above the ice, everything looks the same. A flat frozen ocean.
Mike and Stacy drill through the first three feet of sea ice. (Photo courtesy of Annamarie Pasqualone)
These holes were all drilled by hand. This usually involves two people. One person pushes down on the drill. The second person spins the drill.
Step 4
If the ice is deeper than three feet, we need to attach more flights. In most cases, the ice is thicker than 3 feet.
Stephanie, Stacy, and Mike attach another three-foot flight to the drill. (Photo courtesy of Annamarie Pasqualone)
It might look easy, but we are doing this in cold temperatures, with thick gloves on. It's not easy to work with your hands. (Photo courtesy of Annamarie Pasqualone)
Step 5
Drill some more.
Stacy and Mike drill the second flight in. (Photo courtesy of Annamarie Pasqualone)
Thinks it's easy? We're still drilling. Sea ice is tough! (Photo courtesy of Annamarie Pasqualone)
Some locations have thicker ice and therefore require another flight.
Mike is almost 6 feet tall. Check out the length of the drill! (Photo courtesy of Annamarie Pasqualone)
Some sea ice is thicker than others. Thicker ice requires a longer drill.
If you're doing a lot of holes and depth checking, it's nice to have a motorized drill. Here's an example.
If you have to do a lot of drilling, a power drill can make it easier.
Once you're through the ice, you're ready for a depth measurement.
Step 6
Lower the measuring tape down the hole.
Theodore lowers the tape measure to the ocean bottom below.
Step 6
Record the water depth. Drink hot cocoa.
Nothing celebrates a great day on the sea ice like a cup of hot cocoa.