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Antarctic conservation

August 11, 2010
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Mindy                      August 4, 2010


Temperature:           -17.0°C
Wind Speed:           10 knots
Temp with wind chill: Approximately -30°C
Moonrise:                Below horizon
Moonset:                 Below horizon

 

When we arrived at Scott Base (New Zealand’s Antarctic research station) in February, pools of open water were everywhere.  It was hard not to notice the waters of McMurdo Sound through breaks in the ice.

 

Open waters of McMurdo Sound resized.jpg

The open waters of McMurdo Sound, as viewed from Observation Hill in March. When the sea ice freezes over,

the Cape Armitage Loop runs directly through this area.  © AHT / M. Bell

 

After months of winter, these pools have frozen over.  It is now possible to assess the potential for local travel over the sea ice.  Armed with flags, a GPS unit, measuring tapes, shovels, hot chocolate and a very large drill, we ventured out on to the sea ice.  With Tom, Scott Base winter manager, at the helm, we followed the Cape Armitage GPS route at a cautious pace.  Observing the landscape closely, we stopped to measure, assess and mark potential dangers like cracks in the sea ice.  We also stopped to determine the ice’s thickness at specific points along the route.

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Digging down through the snow to find the ice surface, with Observation Hill in the background.

© Antarctica New Zealand / T Arnold

Drilling into the ice resized.jpg

Drilling into the sea ice to determine its thickness

© Antarctica New Zealand / T Arnold

As a general rule, a minimum of 75 cm of ice is required for sea ice travel.  Measurements gathered from our trip suggest the portion of the route we surveyed is good to go.  When the route is completely profiled, the path of safe travel will be marked with flags and the fun can begin.  Me, I’m keen to get out for a good ski!    

 

 

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It's a wrap!

Posted by Conservators Aug 11, 2010
Author:Jane
Date:04/08/10
Temperature:-20.5°C
Wind Speed:25 knots
Temp with wind chill:-47°C
Moonrise:Below the horizon.
Moonset:

Below the horizon.

 

 

I have just finished conserving a group of tins from Captain Scott’s hut at Cape Evans which has been quite challenging over the last few weeks. With so many objects containing paper elements it has not been possible for George, our paper conservator, to conserve them all, so I have had the opportunity to learn new paper conservation skills from her.

 

Griffith & McAlister made dried food products like tapioca, lentils and macaroni, packed in distinctive square blue tins, wrapped in coarse paper and tied with string. Removing the wrappers can be a daunting process as the corroding iron from the tins is acidic and impregnates the paper, causing the wrapper to become very brittle.

 

Image 1.jpg

Griffith & McAlister tin of Flake Tapioca before conservation. The outer label is torn and stained with iron corrosion causing it to be very brittle.

Credit: AHT

 

I washed the wrappers in water, adding an alkaline buffer to reduce the acidity. The holes in the wrappers were filled with a Japanese tissue paper toned to the same colour as the wrapper, providing strength to weaker areas. The whole wrapper was then lined with a very thin toned Japanese tissue paper. The type of adhesive we use depends on how degraded the paper is.

 

Image 2.jpg

Applying toned Japanese tissue paper to fill lost areas of the wrapper to give it stability and then applying a thin lining for extra support.

Credit: AHT/ N. Dunn

 

As the wrappers dried between layers of blotting paper, I removed the surface corrosion from the tins and applied coatings to the metal to prevent them from deteriorating in the future. The labels were treated similarly to the wrappers and then reapplied to the tin.

 

 

The paper needs to be wet when re-wrapping the tin to prevent it from cracking. The tin was aligned perfectly along the original creases in the wrapper and finally the string was replaced.

 

 

I spent at least eight hours working on each of these tins as there are many different elements to treat on each one. It is often useful to conserve a batch of similar objects at one time, carrying out the same process on a number of objects. This is never boring as each has its own unique set of problems!

 

Image 3.jpg

The Flake Tapioca tin after conservation retains its historic appearance.

Credit:  AHT/J. Hamill