5 Days Until PolarConnect Event!
Are you registered for the live PolarConnect event on Monday, October 3rd @ 1:30pm (EST)? If not, click here. Hope to see you virtually in a few days!
Science Update
The science team is powering through another long day of incubation sampling and CTD casts. Although Incubation 1 is now complete, Incubation 2 & 3 are in the early stages and sampling for both continues. We are also resuming our Palmer LTER station sampling with a deep trace metal CTD cast this morning followed by a conventional cast. We will continue to follow this transect line over the next few days to collect water samples at different stations for a general profile of the area. Kris Gomes and Laura Filliger, both PhD students from the University of Rhode Island (URI), are also collecting samples for their on-board experiment. Needless to say, the science team is BUSY.
Craft Days
Since we are back in the Drake, the science team decided it was time to take advantage of the deep waters and have a little fun. Many oceanographers use equipment that is capable of reaching great depths. This equipment is important for gathering information on the ocean, but it is also a way for them to fire up their creative juices and have a little fun during long days at sea. For the past few days, many aboard the RVIB Palmer have been decorating styrofoam cups. Images of seals, penguins, Antarctica, krill and even a hedgehog or two have found their way onto the cups. In total, approximately 50 cups were decorated and prepared for a trip to the deep ocean on the trace metal CTD.
Marine Technician Jullie Jackson secures the bag of styrofoam cups to the trace metal rosette. During this cast, the trace metal rosette reached a depth of 3050m (~9500ft).
WHY? Take at look at the before and after photos below to see what all the excitement is about and then keep reading to find out why this happens.
Prior to deployment with the trace metal rosette, the styrofoam cup covers the palm of a hand.
After traveling to 3050m (~9500ft) the styrofoam cup barely covers the lower half of the fingers on a hand.
Under Pressure
Hydrostatic pressure, or the pressure exerted by a fluid due to gravity, increases with depth. In the diagram below, you will notice that the water stream leaving the bottom of the container is stronger than the stream at the top of the container. This is because there is a higher level of hydrostatic pressure at the bottom of the water column. This increased pressure helps to force the water out of the bottom hole with more force than the top holes. The water stream in the middle has some force because it is deeper in the column than the top.
As depth increases, the hydrostatic pressure increases. In this diagram, the water stream at the base of the container has the strongest jet because the pressure pushing it out of the opening is higher than at the top.
With every 10m (30ft) increase in depth, an additional 1,270kg (2,800lbs) of force is placed on an object. These object can be anything from a CTD rosette, an underwater ROV (remotely operated vehicle) unit, a fish, a whale and even a styrofoam cup. Equipment like the CTD rosette and the ROV unit are usually made of less compressible material like aluminum, PVC, steel and glass. Fish and whales have adaptations that allow them to survive with the changes in the hydrostatic pressure. Styrofoam, however, is made of a compressible material called expanded polystyrene foam (EPF). This foam consists of air-filled bubbles that stick together to create the form, in this case as cup. At deep depths, the air bubbles are compressed, crushing the bubbles and shrinking the cups. The compression is uniform, so the cup looks almost the same in shape, but not in size.
Classroom Resources
If you are an educator and you are interested in introducing this idea to your students, there are a number of resources available online. I was able to find a few using my limited bandwidth and I have included them below. The catch? You need to contact an oceanographer who will take your cups with them to sea. Contacting these researchers can lead to even greater opportunities for you and your students. This connection may lead to classroom visits (in person or virtual), use of data from the field, etc. I am looking forward to continuing to work with the scientists from this research cruise to develop lessons and activities for my classroom and to share with fellow educators.
The Incredible Shrinking Cup Lab
Ocean Pressure Lab: Styrofoam Cup Squishing
Love From Little Landlubbers
Today's artwork comes from Sandwich, MA. Little JoJo made me a beautiful butterfly to decorate my cabin. Although butterflies are not found in Antarctica, it is a wonderful reminder of life in temperate regions. Thanks JoJo!
Although butterflies don't live in Antarctica, this cute art project is a special reminder of JoJo. Thank you!
Comments