Sunday 22 December. Day 15

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22 12 13 - 20:15

Ah it must be because the days are now getting shorter that the weather has changed! There’s a blizzard on the way apparently!

I stayed up last night to experience the summer solstice, the shortest night, when the sun would hardly dip below the horizon .There was an all night watch from the bridge organised to look out for seals and to do hourly sea ice observations. I deliberately rostered myself on between 2.30 and 4.30am, given our local midnight of around 3am,given we are still on New Zealand time. I stayed up enjoying red wine and company beforehand.

When I headed up to join Tracey the seal biologist at the bridge it was pretty gloomy – no chance of seeing the sunset and sunrise tonight! Low cloud, poor visibility, almost fog. At around 10 to 3 there was a faint rectangular glow on the western horizon which soon disappeared. It became gloomier. Round 3.15 we wondered , maybe it’s brightening up a little. By 3.30 it was definitely a new day dawning – a much brighter shade of gloom in the sky! There were no seals on the sea ice in my two hour shift, but plenty of ice to observe – first year floes, multi year floes, some flat, some aged and ridged, small floes, and bigger packs which the ship sliced through.

I awoke late this morning to a view out the porthole of flurries of snow, and a fresh wind rattling and whistling around the ship. The description on our daily news board was “Weather: grubby. A good Sunday to spend at home with a book”.

It’s been a lazy day. I’ve used it to catch up on writing, others have played scrabble in the bar, talked, read, knitted, the day punctuated by excellent meals.

We enjoyed a great presentation this afternoon by Chris Fogwill about some research he and Chris Turney have just had published about the potential of using ice samples from blue ice for past climate records as a much cheaper and easier option to hugely expensive deep ice coring.

The blue ice areas are where the constant, strong, dry katabatic winds blowing downhill off the continent sublimate (meaning to evaporate straight from solid to gas) the ice from the surface at a rate of around 25cm a year. This causes ice to upwell from below creating a curved strata. Just as layers of sediment can be laid down and then uplifted so they are found as vertical rather than horizontal layers of stratified rock, the same happens with the ice. This means a horizontal transect across the ice can contain ice samples dating back hundreds of thousands of years – and it can be extracted very easily, with a clean sample unaffected by current conditions able to be trenched from about 3 metres below the surface.

 Chris and Chris have looked at blue ice in the West Antarctic, and are very excited by the prospects of blue ice at Cape Denisonwhich comes from the much deeper and more ancient East Antarctic ice dome. They collected a small sample whilst they were there the other day – it wasn’t collected deeply enough to be useful for analysis – but it clearly showed the ancient air bubbles which have the prospect of yielding highly valuable information about past climates.

This trip is such a fabulous combination of Antarctic wildness and science – I’m having a ball!

For more info and photos of our expedition see spiritofmawson.com and the guardian science site.


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