GeoLog

Ocean Sciences

Teachers at Sea: Bon Appétit

Since last week, GeoLog has had the pleasure to host reports from Teachers at Sea. This educational programme, co-sponsored by the European Geosciences Union (EGU) and the French Polar Insitute (IPEV), gives school teachers the opportunity to take part in oceanographic cruises with scientists. This year, Sandrine Vivier and Ana Sánchez, teachers of Biology and Geology in Rodez (France) and Madrid (Spain), respectively, together with EGU’s Education Chair Carlo Laj, join scientists on board of the Marion Dufresne. The research vessel is navigating the South China Sea where teachers will work alongside scientists in collecting marine sediments to retrieve the secrets of deep ocean circulation and understand past variations of the Asian Monsoon. 

Report 6: the ‘Vatel des mers’

Our position today [25/06]

François Vatel, a 17th century cook, is the most famous of the great chefs of French cuisine, which has recently been distinguished as a world cultural heritage by UNESCO. Here, at the Marion Dufresne, we are lucky enough to enjoy meals prepared by a true ‘Vatel des Mers’ – Chef Claude Cornet!At the vessel, is it easy to lose track of time, but we know when it’s Sunday because of the Marion Dufresne tradition of eating croissants for breakfast on this day of the week. On weekdays, on the other hand, Chef Claude bakes wonderful French baguettes for breakfast.He also prepares delicious lunches and dinners, keeping with the theme of French cuisine. Assiette de crevettes with mayonnaise, tournedos bordelaise, coquille de poisson, entrecôte béarnaise are some of the dishes we’ve had the pleasure to eat for lunch. Mixed salads, lasagna, and fish fillets have been served at dinner time. And all the meals invariably end with a platter of French cheeses and fresh fruit!

Chef Claude Cornet

The starter for today’s lunch

Chef Claude welcomed us in his kitchen while preparing lunch. His job includes cooking as well as buying all sorts of ingredients beforehand. He gets the meat in Brazil, the rice in Malaysia, the alcohol in France, the fresh vegetables and fruits at every port call. These ingredients are then stored inside the different refrigerators and deep freezers of the Marion Dufresne: meat is kept up to 6 months, fresh vegetables for up to 3 weeks, and fruits for 5 weeks.

Claude can count with the much-needed help of three assistants. At times, when the Marion is used as a supply boat for the French territories in the Southern Ocean (Amsterdam Island, Crozet, Kerguelen archipelago) and Antarctica (Terre Adélie), the team of cooks prepares food for up to 140 people and the scientific party!

Chef Claude and one of his assistants preparing dessert

Thank you Claude and your team for making life on board all the more enjoyable!

By Sandrine Vivier, Ana Sánchez, and Carlo Laj

Teachers at Sea: the ‘brain’ of the Marion Dufresne

Since last week, GeoLog has had the pleasure to host reports from Teachers at Sea. This educational programme, co-sponsored by the European Geosciences Union (EGU) and the French Polar Insitute (IPEV), gives school teachers the opportunity to take part in oceanographic cruises with scientists. This year, Sandrine Vivier and Ana Sánchez, teachers of Biology and Geology in Rodez (France) and Madrid (Spain), respectively, together with EGU’s Education Chair Carlo Laj, join scientists on board of the Marion Dufresne. The research vessel is navigating the South China Sea where teachers will work alongside scientists in collecting marine sediments to retrieve the secrets of deep ocean circulation and understand past variations of the Asian Monsoon. 

Report 5: At the controls of a research vessel

Inside the bridge of the vessel

The ‘brain’ of the Marion Dufresne, always alert during the oceanographic cruises, is located at the bridge – the room from where the vessel is commanded.

To navigate the oceans of the world, the Marion Dufresne uses three shipboard GPS satellite systems, as well as nautical charts. Weather reports and charts obtained daily from Bon Voyages Systems, a private company, are also used for navigation. We were a little worried in the first few days when, looking at the most recent weather chart, we realized that a rather severe tropical storm was sitting on the area where our coring sites were located! Luckily for us, the storm moved away from the zone and so far we have found only calm waters.

Forecast of stormy weather in the area of the core sites

Captain Bernard Lassiette and his officers showed us the different instruments present at the bridge of the vessel. We were first struck by the two radar screens, right in the centre, which operate at two different wavelengths, 3 cm and 10 cm. The one operating at the shortest wavelength yields very precise images but is sensitive to atmospheric phenomena such as rain, while the other one provides less precise images but is much less sensitive to these kind of atmospheric perturbations. Both detect other vessels or the coast at a distance of about 50 km.  Also in the centre is the rudder, which can be computer controlled or hand manoeuvred.

The two radars

On the port (left) side, there are two panels similar to those we saw in the machinery control room a few days ago. The commands originate from here and are reproduced in the ‘heart’ of the Marion Dufresne four decks below.

But the most spectacular feature in the bridge is the control station – the real ‘brain’ of the ship – on the starboard (right) side. This station is particularly important during the long coring sessions, when the Marion Dufresne cannot move by more than two or three meters during the entire operation.  To keep the vessel in the same position, it is important to take wind and surface current into account. The ‘brain’ does this (up to rather bad sea and weather conditions) and automatically controls the two propellers and the thruster to keep the Marion Dufresne stable. At times, however, man replaces the machine: the ship officers can control the boat manually using a ‘joy stick’.

The joy stick to control the boat

As for the ongoing coring operations, we obtained three new cores  (35, 49 and 52 meters long) with Casq and Calypso since our last report! The activities in the Marion Dufresne don’t stop: the team continues to work, preparing, labeling, and storing the cores. At the same time the scientists study the main characteristics of the samples: color, density, magnetism, foraminifers, and so on.

Ana and Sandrine packing a Casq core

There is much to discover on board of the vessel!

By Sandrine Vivier, Ana Sánchez, and Carlo Laj

Teachers at Sea: the first coring site!

In the next two weeks, GeoLog has the pleasure to host reports from Teachers at Sea. This educational programme, co-sponsored by the European Geosciences Union (EGU) and the French Polar Insitute (IPEV), gives school teachers the opportunity to take part in oceanographic cruises with scientists. This year, Sandrine Vivier and Ana Sánchez, teachers of Biology and Geology in Rodez (France) and Madrid (Spain), respectively, together with EGU’s Education Chair Carlo Laj, join scientists on board of the Marion Dufresne. The research vessel is navigating the South China Sea where teachers will work alongside scientists in collecting marine sediments to retrieve the secrets of deep ocean circulation and understand past variations of the Asian Monsoon. 

Report 4: The first coring site!

Our position today [21/06]

Our adventure continued as the ship arrived to the first coring site on Wednesday evening. From now on, we are divided into three watches (sometimes called shifts). The three groups work 8 hours a daily, divided into two periods of 4 hours each.Operations began with a hydrological experiment: a rosette holding 24 opened bottles and a CTD (Conductivity, Temperature, Depth) sensor was lowered down into the sea, almost reaching the bottom at 660 meters. Then it was pulled up and at chosen depths, the bottles were successively closed by a command from the boat. In this way, each bottle recovers a sample of the water at the depth at which it was closed. In the end, we recovered 24 bottles (12 litres) each sampled at a specific depth and temperature, and a CTD profile. Once on board, our colleagues from the University Sains Malaysia in Penang, immediately froze and/or analysed these water samples to test in particular for their pH.

The rosette ready to be lowered into the sea

After this experiment was completed, the team on the vessel attempted to core sediments with the Casq corer for the first time. This is a very large 25x25cm gravity square corer, 12 metres long. It has the capacity to recover a large amount of undeformed sediment.

Unfortunately, on this first attempt, the Casq was empty when it was pulled back on the deck! The system that traps the sediments in the corer as it is pulled up and back on to the ship did not work properly and the sediment was lost.

The Casq corer

On the other hand, everything worked perfectly for the Calypso piston coring that the team performed immediately after: the corer recovered 28 metres of sediment with a core diameter of 10cm! Not bad at all! Microscope observation of a small amount of sediment from the core catcher points to an assembly of several fossil foraminifera (a type of marine plankton), which gives scientists an idea about the ‘age’ of the sedimentary sequence reached by the corer.

The second Casq coring was also successful, with the team recovering over 7 metres of undeformed sediments. And because Casq recovered such a large amount of sediment, the scientists on board could sample part of it for the teachers. Yes, you teachers will have ‘real’ marine sediments to show to your pupils!

As for the Calypso samples, it’s hard to imagine how we could bring a 28-metre core back to the laboratory in one piece… Naturally, the team cut the Calypso core into 1.5-metre segments (called sections), each carefully labelled so that its order is known with no possible error. These segments will be split afterwards longitudinally into two halves, one labelled working (W) and the other archive (A). Scientists do preliminary work on board on the W halves (description to come!) before both halves are sent to the laboratories.

Cutting the Calypso corer into 1.5m sections

The cutting, labelling, and storing of the samples went on all night long and continued in the morning. Everyone was rather exhausted at the end but excited about the job in hand. It all starts again tonight as we reach our next coring site!

If you have any questions for us, please leave them in the comments section of this post.

By Sandrine Vivier, Ana Sánchez, and Carlo Laj

Teachers at Sea: the ‘heart’ of the Marion Dufresne

In the next two weeks, GeoLog has the pleasure to host reports from Teachers at Sea. This educational programme, co-sponsored by the European Geosciences Union (EGU) and the French Polar Insitute (IPEV), gives school teachers the opportunity to take part in oceanographic cruises with scientists. This year, Sandrine Vivier and Ana Sánchez, teachers of Biology and Geology in Rodez (France) and Madrid (Spain), respectively, together with EGU’s Education Chair Carlo Laj, join scientists on board of the Marion Dufresne. The research vessel is navigating the South China Sea where teachers will work alongside scientists in collecting marine sediments to retrieve the secrets of deep ocean circulation and understand past variations of the Asian Monsoon. Check out the first and second posts of this series.

Report 3: How a research vessel works

Location of the Marion Dufresne

The ‘heart’ of the Marion Dufresne, beating steadily 24/7, is its machinery. And today we received a very special treat: Chief Engineer Alain Rolland invited us for an hour visit to discover the inner secrets of the vessel.

From Deck E, which is the main deck for many operations, we descended a steep staircase to Deck D and started by visiting the control room. Here, a glance at the different and numerous control panels tells Alain that everything is working properly, or eventually what adjustments need to be done to correct small anomalies here and there.

We then moved further towards Decks B and A. The noise became very strong – so much so we were required to wear safety ear muffs – and the temperature increased: a thermometer hanging on a wall read 42°!

Here, Alain explained us a bit about how the boat works. Three diesel engines drive alternators that provide the necessary energy to two electric engines, which in turn propel the boat via two propellers. An electric motor is much more flexible than a diesel one, and this way of functioning is extremely important when the boat has to stay steady during the coring time.

Alain explains how the vessel works

The power from the diesel generators is also crucial to support life on board the vessel. It is used to evaporate sea water, which is distilled and mixed with some minerals that make it drinkable. As a result of this process, we can drink water from every tap on the Marion Dufresne. About 20 tons of water are produced in this way every day. Power for the entire electric system of the vessel is also generated by the diesel engines.

The highest possible power that can be generated is 6000 MW; in transit, in a balance between speed and efficiency, this value decreases to about 2500 MW. Life on board requires about 1000 MW.

At the prow, there is also another element of the vessel’s machinery: a transversal engine called a thruster. A propeller placed in a channel can project water either to the right (starboard) or to the left (port), which is very useful to stabilize the boat.

With more knowledge about own the Marion Dufresne works, we continue our itinerary. We’ll be sure to keep in touch!

Our itinerary

By Sandrine Vivier, Ana Sánchez, and Carlo Laj