The Spirit of Mawson - Australasian Antarctic Expedition 2013 - 2014

Australasian Antarctic Expedition

Day 4 – A full day of sub Antarctic science

Posted by Ben - 30 November 2013

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Hello everyone, lots of exciting things happened today! Overnight the wind picked up significantly, by 9am this morning when Zodiacs were leaving the ship it was blowing between 20 and 30 knots! The Shokalskiy made its way into Rapanui Cove to escape the southeasterly breeze, and the numerous science teams split up from there.

The terrestrial ecologists headed towards Laurie Harbor, but on their first attempt the prop became stuck in some kelp fronds and failed, leaving the zodiac at the mercy of the winds. We were blown onto tiny Ocean Island with only two paddles to prevent us smashing into the rocks. To help things, we encountered a heavy hail squall at this point, and discovered that our VHF radio had flat batteries! After digging out a sat phone and dialing up a replacement Zodiac, we forced a path through the kelp and resumed the journey down the harbour, fighting the waves, current, wind and hail every step of the way. After finally reaching the drop off point, we let the botany team free to go do their thing and headed back to the ship. After a 2 hour battle to get down the harbour, it took 10 minutes to run back to the Shokalskiy!

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The lake coring group working out their location

The lake coring group again failed to find a lake to core, but did manage to collect 652cm of peat from a bog on Auckland Island, not far from the Coast-watchers hut used during WWII. Battling occasional squalls (and accompanying hail) we triumphantly marched down to the shore with our peat and lots of surface samples from the bog.

Today the marine ecologists were very excited to try their new ROV (Remotely Operated Vehicle), a robot equipped with cameras and lights to explore the seafloor. After the viewing screen and the driving computer were set up in the lab, the robot was lowered in the water. A fiber optic cable 300m long connects the ROV with the driving computer on board and the team tried to drive the robot as far as possible towards the rocky seafloor close to the island coast. Unfortunately, the cable wasn’t quite long enough to reach all the way. Despite this, the 2 tryouts were a success: the robot is working and sent back great footage of the seafloor. The ROV is ready for the best the Southern Ocean has to offer!

Elsewhere on board another group did a test run with the CTD (Conductivity, Temperature, Depth) probe in shallow waters off the coast of Auckland Island. The CTD probe is a very valuable little toy that can measure basic oceanographic parameters of the seawater such as salinity, temperature and depth. It took a little bit of troubleshooting at first, but in the end we managed to get nice data out of it. We all can't wait to see it in action in a true oceanic setting.

The ornithologist team landed at Ewing Island to record bird numbers and undertake burrow density surveys. We first noted a nesting skua and 11 Great Petrel chicks near the boat landing, before rushing headlong into the incredibly knarly scrub. Crawling on hands and knees (and sometimes stomachs), we avoided the groaning sea lions and the sticky bog. Unfortunately, the video endoscope revealed most bird burrows empty. The presence of nests in the burrows showed they were in use, but no one was at home. We may be visiting a little early for birds to be incubating their eggs. We found one sooty shearwater. We even had the chance to take two diving petrels out of the burrows to measure their bills, wingspan and weight.

Rebecca from the University of Otago spent the morning on Ewing Island crawling around among the fallen tree-daisy branches, dodging breeding yellow-eyed penguin, fluffy petrel chicks and the odd bull sea lion.  Lovely. Unfortunately the dense forest canopy did not provide suitable terrestrial onchidiid slug habitat, so in the afternoon her sights were set on a choice piece of headland – Tucker Point.  Jumping from the zodiac onto the basalt columns she searched the rockfells back from the intertidal zone.  With the first rock she turned - there it was… the elusive slug she had travelled hundreds of km to find.  Every successive rock turned was the same, they were everywhere!

All in all a wonderful day in the sub-Antarctic. In the Spirit of Mawson lots of science and adventure both!