This week at Macquarie Island: 8 November 2013

Three members from BAS (British Antarctic Survey) arrived on L'Astrolabe, and they tell us about their study of lake bed sediment. The Macca Gallery shows us more fantastic images from around station and the island

BAS (British Antarctic Survey) investigate lake sediment

Dominic Hodgson, Steve Roberts and Wim van Nieuwenhuyze (University of Ghent) have just arrived on Macquarie Island, the second field location in a new 4-year NERC (Natural Environment Research Council) funded project using lake sediments to investigate changes in Southern Hemisphere Westerly wind strength over the last 20,000 years.

Fieldwork on Macquarie Island is being undertaken in conjunction with Krystyna Saunders (Universities of Tasmania/Bern) and our long-term collaborators from Ghent University with key support from Australian Antarctic Division (AAD).

After a week of pre-departure training in Hobart, at the AAD, and on top of Mount Wellington, L'Astrolabe dropped us off on Macquarie Island in a textbook ship-shore small boat operation. We received a very warm welcome from everyone on base, and, after further in-field training, will be man-hauling our coring kit up onto the plateau to take sediment cores from salt-spray influenced lakes on the western side of the island.

We got off to a flying start last week with seven sediment cores taken in two days over last weekend from Emerald Lake, our main target site. We were fortunate to have perfect conditions with virtually no wind on the first day, which made setting up ropes and coring more straightforward.

With the sun out all day on Saturday and lake looking like a pristine mirror at times, we worked efficiently. This provided a good opportunity to take plenty of fieldwork (and landscape) photos, as well as collecting, logging and wrapping all cores and returning them safely back to base.

A big thanks to Mark, Josh and Greg for helping carry some of our heavy kit loads up to site and to Mark for guiding over the weekend and his help with setting the ropes and other aspects of coring – all of which was very much appreciated.

From previous analysis of cores taken from this lake, undertaken by Westerly Wind project co-leader Krystyna Saunders, sediment at 12–84cm depth likely represents ‘baseline’ sediment deposition processes in the pre-human era back to about 20,000 years ago. Although some natural compression of the lower sediments has occurred, lake sediment cores from the island similar to these have been used to place the relatively rapid increase in sedimentation associated with the last century or so of human occupation into a longer-term context.

However, the main aim of our current project is different – we intend to use newly collected cores to investigate detailed changes in sea salt inputs into lakes on the western side of the island to determine relative changes in Westerly Wind strength through time. The Emerald Lake cores are now stabilised back at base and will return to the mainland, with others we hope to collect during November, for further detailed investigations.

See @steveroberts60 on Twitter for updates on progress and photos.

Wim, in a yellow weather proof jacket, and Dominic, in a orange jacket, on the snow covered plateau, both carrying packs loaded with the coring kit
Wim and Dominic in the field carrying the coring kit
(Photo: Steve Roberts)
Emerald Lake on a light wind day so the water reflects the snow covered hills and the patchy cloud filled sky. This is the lake from which we take the sediment cores
Emerald Lake from which we take the sediment cores
(Photo: Steve Roberts)
Arriving at Bauer Bay hut. picture taken from just above the hut shows a a light cover of snow over the hut and landscape, while Wim, Dominic and Mark check the hut. There is snow falling
Arriving at Bauer Bay hut
(Photo: Steve Roberts)
Dominic setting the ropes across the lake from our small inflatable dingy to provide a stable coring platform to work from
Dominic setting the ropes across the lake
(Photo: Steve Roberts)
Depth measuring of Lake Emerald by Dominic in the small inflatable dingy. With very light winds the lakes surface reflects the snow covered hills and the partly cloudy sky.
Depth measuring
(Photo: Steve Roberts)
Taken from a hill above Emerald Lake, we see a snow covered landscape with Dominic on the inflatable dingy in the middle of the lake where at the intersection of two yellow ropes that are stretched, perpendicular to each other, across the lake. Mark, Wim and the equipment can be seen on the right shore of the lake
Emerald Lake sampling
(Photo: Steve Roberts)
Mark Gasson crouching next to the first Livingston piston core drive of about 84cm length
Mark next to a Livingston piston core from Emerald Lake
(Photo: Steve Roberts)
Dominic sits next to a vertical UWITEC surface core from the central point. The flocculent uppermost 12cm of this core most likely represents historical disturbance in the catchment associated with the introduction of non-native animals over the last century or so
Dominic sits next to a vertical UWITEC surface core from the central point. The flocculent uppermost 12cm of this core most likely represents historical disturbance in the catchment associated with the introduction of non-native animals over the last century or so
(Photo: Steve Roberts)
View of North Head and the station from the top of the Doctors track. In the foreground, Josh, Dominic and Wim take in the view
View back down to base on recce walk
(Photo: Steve Roberts)

Macca Gallery

This weeks Macca Gallery has images of late season snow, and the magnificent wildlife which always enthrals us.

Southern Right whale in Buckles Bay. The top of the head and back are above the water surface, with barnacles visible on it head
Southern Right whale in Buckles Bay
(Photo: Lionel Whitehorn)
View from the Ham Shack — shows the snow covered escarpment and plateau beyond the isthmus. Some of the station buildings are visible on the isthmus
View from the Ham Shack
(Photo: Barend (Barry) Becker)
Gentoo penguin family comprising of an adult sitting on the nest with two chicks appearing under the brood pouch, while the other adult brings some grass to add to the nest
Gentoo penguin family
(Photo: Barend (Barry) Becker)
Several elephant seal weaners in the foreground on East Beach with the east coast escarpment and Nuggets in the background, bathed in bright sunlight
Plenty of elephant seal weaners appearing on the beaches
(Photo: Barend (Barry) Becker)
Campbell-Stokes sunshine recorder. A glass ball which focus sunlight to burn onto a card. The view in the ball is the inverted and concave distorted image of the escarpment, station buildings and log fence of the weather enclosure
Campbell-Stokes sunshine recorder
(Photo: Barend (Barry) Becker)
Plenty of wildlife including king and gentoo penguins in the foreground with many elephants seals on the rocky beach — The azure blue waters of Hasselborough Bay and the vegetation covered North Head provide a contrasting back drop
Plenty of wildlife — Hasselborough Bay and North Head
(Photo: Barend (Barry) Becker)
Role playing. A couple of elephant seal weaners prcticing their fighting skills by chesting up to each other
Role playing
(Photo: Barend (Barry) Becker)
A beautiful image of Emerald Lake with an almost mirror water surface. In the foreground is the lake shore adorned with a variety of vegetation, while behind the lake are snow covered hills, which are reflected on the lakes surface
Emerald Lake
(Photo: Steve Roberts)