28 February 2020 Looking at the Data

All data tells a story. Sometimes, that story is, “You set up your experiment wrong,” or “An essential piece of equipment is broken.” Sometimes, a pattern leaps easily off the page and it all makes sense to you. And sometimes, it is the way you look at the data that makes the story interesting. For example, the Circumpolar Deepwater (CDW) is a current that flows through the southern ocean and is at most a few degrees warmer than the waters surrounding it. If you were looking at a set of data that showed the average temperature of ocean waters around the world, you might not be all that impressed by the minuscule difference in CDW versus non-CDW water. However, here in the Amundsen Sea off the southwest coast of Antarctica, a few degrees difference in water temperature is the difference between ice that is stable and ice that is disintegrating. In order to write our story, we need our data to show where that warmer water is. And remember we recruited some special partners to help us in this effort.

An elephant seal on Edwards Island #4, Antarctica, tagged under Permit FCO No. 03/2019-20.

The seals that were tagged with data-collectors have been hard at work, diving and returning to the surface, and contributing more and more data to the story of what is destroying the Thwaites Glacier. Remember, we tagged two species of seals - the elephant seals are uglier, larger, and often descend to depths above 2000 meters, while the Weddell seals are cuter, smaller, and tend to max out at 1000 meters or so. Here is some data collected from the tag of a single elephant seal. What kind of story do you see in these graphs?

Data on dive depth collected from an elephant seal tagged on February 6, 2020 under Permit #03/2019-20. Data on water temperature by depth collected by an elephant seal tagged on February 6, 2020 under Permit FCO No. 03/2019-20.

I see that one of our elephant seasl found the CDW. Here is a map showing where she and the other tagged seals have been. This one is E088 (tagged with Permit FCO No. 03/2019-20).

Seal locations are recorded and data is collected each time the seal surfaces. Elephant seal E088 has traveled the furthest diatance since she was tagged on Feb. 6, 2020 on Edwards Island #4 with Permit # FCO 03/2019-20.