Drilling sea ice cores

Ice cores are cylinders of ice that come from ice sheets, glaciers or sea ice. They are frozen archives that give us snapshots of the past and the present.

Air bubbles – gases trapped in ice – provide information about what Earth’s climate was like over hundreds of thousands of years. Other things in the ice like salt, dust or ash provide information and timelines about wind patterns or volcanic activity over time.

Sea ice cores provide information about ice structure, salinity and growth rates. Platelet ice layers also provide information about unique cold-water habitats for algae, bacteria and other tiny organisms – the base of the Antarctic food web.

Some of the ice samples are studied on site in Antarctica, but many are carefully packaged and shipped to Aotearoa New Zealand where they are stored in purpose-built laboratories.

Associate Professor Inga Smith from the University of Otago provides a brief introduction to how and why her team collects sea ice cores.

Point of interest

• The scientists are using a pencil to make notes about their field work. They cannot use pens as the ink freezes in the cold weather!

Questions for discussion

• Why are the scientists ‘digging out’ first?

• What do you see/observe happening in the video? For example, what equipment are they using?

• Why do you think the ice cores are sent to New Zealand for study?

• Why would the scientists need a backup core?

Transcript

Associate Professor Inga Smith

This is the University of Otago sea ice monitoring station that you can see digging out at the moment. So, we’ll take three sea ice cores at this site. This is our second one. So, the first one had the temperature measured every 10 cm and then chopped up into 10 cm chunks for salinity measurements, put in pottles and there in the back and melt them out. The second ice core that they’re finishing up now is for sea ice structure. So, we’ll send that back to New Zealand on tomorrow’s C-17 flight, and then we will carve that up and look at what sea ice structure looks like at this site.

And then we’re going to break for lunch now and then they’ll do another core, which is also for structure, and that’s the backup core that’ll stay here once we make sure that the other one has got to New Zealand safe.

Acknowledgements

Associate Professor Inga Smith, University of Otago

Anthony Powell, Antarctica New Zealand
Daniel Oskam, Antarctica New Zealand
Chris Pooley, University of Otago
Stephen Trimble, Antarctica New Zealand
Antonia Radlwimmer, University of Otago
Mel Howard, Antarctica New Zealand
Andrea Foley, University of Otago
Footage courtesy of Dianne Christenson and Carol Brieseman
Dianne Christenson and Carol Brieseman visited Antarctica with support from the Antarctica New Zealand Community Engagement Programm