FAU expedition: bountiful treasures of the deep sea

First summary of the expedition to the southwest Pacific Ocean

The geologists from Erlangen and their colleagues from Hanover, Bremen, Kiel and Canada returned from their expedition on the research ship ‘Sonne’ highly satisfied. ‘In just under four weeks we were able to conduct eleven successful dives in the southwest Pacific,’ says Prof. Dr. Karsten Haase of the Department of Endogenous Geodynamics at FAU. The discovery of one of the hottest springs ever to be found on the ocean floor of the Pacific was especially spectacular. With more than 350 degrees Celsius, it fights upwards against the tremendous pressure of almost 1900 metres of water.

Only two springs are known in the eastern Pacific and the Atlantic that are slightly hotter. Prof. Haase will share the experiences he made on his expedition with the public in a talk at the Long Night of Sciences on 19 October at 8 p.m. at GeoZentrum Erlangen, Schlossgarten 5.

12 July 2013: Finally the surface of the ocean is calm enough to steer the diving robot Kiel 6000 to the submarine volcano Nifonea northeast of the island Erromango, which belongs to the island nation of Vanuatu. The further the sophisticated device ventures into the caldera, the volcano’s ‘cauldron’, the more full of life are the images it sends back up: everything is teeming with pink-headed tubeworms and longish seashells. Microbial mats cover the rock. Crabs, snails, a few sea anemones and fish dot the living landscape. Two ‘black smokers’, spilling hot, mineral-saturated water, come into view; precipitated substances have formed a three metre-high chimney that is perfectly suited for taking samples. There can be no doubt about the active geological forces at play in this area.

‘That was the highlight of the expedition,’ is the enthusiastic opinion of Haase’s group member, Dr. Christoph Beier. Deep sea rocks, water samples and organisms collected from an area of several hundred square metres will keep the participating scientists busy for the next two years. The 1.1 million euros in funding from the Federal Ministry for Education and Research were invested soundly.

Outlier volcanoes

The ocean floor of our planet, in some ways harder to explore than the surface of the Moon or even Mars, is full of surprises once one manages to approach it. Four previously unknown volcanoes were discovered, some in completely unexpected locations. Where the Australian continental plate subducts under the Pacific plate, magma – liquid, hot rock that cools down and solidifies into lava – wells from Earth’s mantle. Although it is common to find a subduction zone marked by a chain of volcanoes, it is unusual to find more volcanoes up to 30 kilometres away in the ‘back country’.

‘Two opposite geodynamic forces are at work here,’ Haase explains. The upper plate is not only being pushed, but it is also being expanded in the other direction. How does that happen? ‘We don’t know yet.’ The researchers have to use the rock samples they brought back to investigate.

Oases of bubbling energy

Expeditions to little-explored regions of the Pacific also mean that maps are completed and Earth’s surface is surveyed. While the ocean floor can be mapped by satellites, the results are much less accurate. The ‘Sonne’ has a multibeam echosounder. ‘Ninety-six beams scan the ocean floor,’ the geologist explains. While the ship makes several passes, exact orientation becomes possible and high-resolution maps are generated strip by strip.

This allows the inhabitants of Vanuatu to get to know their surroundings properly for the first time. Some islands jut steeply from the water with almost vertical rock walls under the surface. Tranquil beaches for snorkelling and diving are sought in vain. A scientist from Vanuatu on board was fascinated to see the environment she lives in. Perhaps she was also a little shocked: the ocean floor is almost dead a few hundred metres off the coast. There are surprisingly few living creatures in the stony deep sea desert.

This only changes as one approaches the hot springs – and thoroughly so. Hot solutions from Earth’s mantle contain sulphur; the deep sea organisms create the basis for their survival far from sunlight and photosynthesis through oxidation of this substance. While this kind of ‘nutrition’ may seem strange to us, it is currently assumed to have paved the way for life on Earth. Furthermore, black smokers unearth treasures, at least for humans: traces of copper, zinc, iron, silver and gold indicate possible deposits. However, isn’t mining rather complicated two kilometres under sea level? ‘It isn’t really about that,’ Karsten Haase admits. ‘Rock analysis allows us to draw conclusions about where to look for metal deposits on land.’

Through the eyes of a robot

Although biological tests are the domain of his colleagues in Ottawa and Victoria, the geology professor and his team member find it hard to tear themselves away from video footage of the lively activity on the ocean floor. ‘It’s just fantastic to watch a crab feed at this depth,’ Haase remembers. The diving robots that have been in use for about 15 years have revolutionised research, he says. Germany boasts two such robots (highly sought-after by scientists) and four large research ships – rather good equipment for a nation with few coastal areas. The German Research Foundation (DFG) also know to show their appreciation when scientific institutions from landlocked areas commit themselves to this kind of research. Provided the necessary expertise is there, that is – as with GeoZentrum Erlangen.

With 37,500 students, 640 professorships and about 12,000 employees, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), founded in 1743, is one of the largest universities in Germany – and as recent surveys show, among the most successful and strongest research universities. Currently ranked 10th in the Funding Ranking published by DFG, FAU belongs to the same league as the German ‘Universities of Excellence’. In addition to the Cluster of Excellence ‘Engineering of Advanced Materials’ (EAM) and the Graduate School of Advanced Optical Technologies (SAOT), which was founded as part of the Excellence Initiative, FAU currently has more than 30 co-ordinated programmes with DFG funding.

The University of Erlangen-Nürnberg offers more than 150 degree programmes, among them 5 Bavarian Elite Master’s degree programmes and more than 32 with a distinct international focus. No other German university offers such a broad and interdisciplinary range of subjects on all qualification levels. FAU students enjoy global mobility through over 500 partnerships with higher education institutions in more than 70 countries.

Further information:

Prof. Dr. Karsten Haase
Phone: +49 (0)9131 85 22616