January 12-14: Ninnis Glacier

Post from VIMS graduate student Mar Arroyo.

12 – 14 Jan 2017
67° 40’ S, 146° 38’ E
Ninnis Glacier

After an exciting time at the Mertz Glacier, we have now sailed further east to the Ninnis Glacier and polynya for the next round of CTD stations. In fact, this voyage is the first ever to deploy CTDs in this region as this area of East Antarctic ocean is rarely explored! To our knowledge, there has been only one ship to reach the Ninnis Polynya: the US Navy’s USS Glacier in 1979 to collect a sediment sample from the seafloor during Operation Deep Freeze. This is almost like a consolation prize for the failed efforts at the Totten Glacier a few weeks ago.

Exposed dolerite bedrock at the western end of the Ninnis Glacier. The landscape was incredible.
Exposed dolerite bedrock at the western end of the Ninnis Glacier. The landscape was incredible.

Because this area is extremely understudied, we are zig-zagging around the polynya to map out the bathymetry of the seafloor with the ship’s sounding system, dropping CTDs along the way. The sounding system had picked up a relatively deep trench, recording over 1600m in an area with surrounding depths of ~800m.

The seas were calm, and the weather was perfect for two days of non-stop CTDs. Now, we’re forced to leave the Ninnis Polynya earlier than planned or risk having the thick, multi-year fast ice cut off our only exit to open seas.

mar12

On to the next mission: CTD stations along the repeat line SR03.

Mar