Articles tagged with: Marion Dufresne

RHUM-RUM launched

Written by Guilhem Barruol, Karin Sigloch on Friday, 07 September 2012.

15 September 2012

Indian Ocean seen from Le Port de La Réunion

From Sept. to Nov. 2012, we will be installing most of our instruments: about 30 land stations in La Réunion, Mauritius, Madagascar, and the Seychelles, as well as 57 ocean-bottom seismometers during a month-long cruise aboard RV "Marion Dufresne". The cruise starts on September 22nd, we expect to be blogging regularly from the ship.

Ready for departure

Written by Chris Scheingraber, Maria Tsekhmistrenko on Monday, 24 September 2012. Posted in Cruise 2012

22 September 2012

Looking for our containers.

The French and German scientific teams arrived well on the island of La Reunion. Unfortunately, our departure will be delayed (for a few days?) due to a strike of dockworkers that we learned about on short notice. Since they are supposed to load our equipment on board, the Marion Dufresne is still docking in Le Port de la Réunion. Despite the problems we are facing, the crew and the scientists are in good spirits. We just hope that the strike will end soon so that we can finally start our mission.

20120922-01 md

30 scientists in a golden cage

Written by Heiner Igel on Monday, 24 September 2012. Posted in Cruise 2012

24 September 2012

Blogging from a golden cage.

Here we are, ready to fight the open seas and drop down a few dozen seismometers into the abyss of the Indian ocean .... BUT ... the dockworkers decided (after many years for the first time) to go on strike just the day when we were supposed to start loading. And they seem to continue. No end in sight.
Yes. We found "our" four large containers somewhere in the harbor but unfortunately - despite the increasing use of the ship's "gym" (two bikes, rowing machine, running machine, weights) - we do not feel strong enough to carry them to our dock without machine support.
It is day 4 on the ship. With no real task, except waiting. Some sit on the two chairs outside the scientific room with view to the rising slopes of volcanic La Reunion, waiting for the next eruption (Jason), that could be viewed from a comfortable distance. Others go running along the beautiful seashore park after leaving the ports' gate (2 km away from the ship), coming back with ideas for a new seismology rock song (Jean-Paul). It is amazing what the sudden unexpected availability of time can do to you! Marvelous! Inspiring!
What keeps us from jumping overboard in despair are the meals. 12:15 and 19:15. Four courses. Entrée, plats, cheese, dessert. Excellent French cuisine (another reason for the increasing use of the gym). Followed by coffee and discussions on science, the world, our situation, the region. What an opportunity to work with colleagues from La Réunion, Rodrigues, Mauritius, Madagascar, and to learn more about these remote regions!
This situation is dangerous! 30 scientists with lots of time, good food, no internet access? I think there could be some explosive new ideas around the corner!

Free the Marion Dufresne!

Written by Karin Sigloch on Friday, 28 September 2012. Posted in Cruise 2012

27 September 2012

Political action. (Photo by Kasra Hosseini)

We are still in port, blocked by the strike of the harbor workers. Now the deal is that we get the harbor to ourselves, while the striking workers, camped in front of the main gate, are ensuring that nobody disturbs our ship on sabbatical.

Science has been all talk and no action so far (daily seminars, dinner discussions, dreams...). But witnessing much political action around us, we got into it ourselves. Our colleagues from La Réunion spent many hours at the main gate, trying to understand the concerns of the workers, and whether a pragmatic solution for our four blocked containers might be found. We also turned to the island's Prefect, since our experiment represents a major investment of taxpayer's money, and pertains to volcanic risk assessment.

The photo shows an earlier outreach effort in the "Free the Marion Dufresne" series: Wave "Good morning and SOS" to the Prefect. We learned that his helicopter was supposed to survey the scene of the deserted harbor early in the morning, so we also wanted to be seen. We chose the parking lot outside the ship, and white towels for good visual contrast, but the helicopter never appeared.

Yesterday we did manage to make direct contact with the Prefect, got a helpful response, and thought our problem solved – until that hope evaporated again at the harbor gate. Five days after our scheduled departure, our cruise leader can still only dream about scientific action on the seafloor...

20120927 02 guilhem souslo c2

First ocean-bottom seismometer deployed.

Written by Chris Scheingraber, Simon Stähler on Sunday, 30 September 2012. Posted in Cruise 2012

29. September 2012

First ocean-bottom seismometer deployed (Picture: Chris Scheingraber).

During the first day spent entirely on the sea, we set up the lab, tested the release mechanisms for the ocean-bottom seismometers, and successfully deployed the first seismometer.

Fully operational

Written by Chris Scheingraber, Maria Tsekhmistrenko on Tuesday, 02 October 2012. Posted in Cruise 2012

30 September 2012

Our colleague Olivier makes a quick cell phone call while the Marion Dufresne passes his native island of Rodrigues (500 km east of Mauritius, 33,000 inhabitants). (Photo: Karin Sigloch)

It seems like an endless and beautiful ocean is surrounding us. The last island on our journey (Rodrigues) rolled by hours ago, the last ship this morning. After the release of the first seismometer and a small celebration given by IPEV to honor this moment, we are getting into a daily routine.
Some of the scientists are working on recording and controlling bathymetry, gravity and magnetic data, while a smaller part are preparing seismometers for deployment. 24 hours a day, there is continuous activity. The OBS deployment teams do not care about meals or bedtimes, they have to be ready at all times. Even though we miss out on sleep and only rarely find the time to sit together and have a chat, we are definitely much happier with these circumstances than we were during the strike.

The workshop: ocean-bottom seismometers ready to take a dive. (Photo: Karin Sigloch)

La Vie en Rose

Written by Carmen Gaina on Wednesday, 03 October 2012. Posted in Cruise 2012

Or Science is really fun, enroll now ! (3 Oct 2012)

Rainbow and sunset over Mauritius Island

One has to be careful when making wishes: they may come true, and then you need to deal with the happiness overdose! For many years I was hoping to join a scientific cruise on a French vessel – I suppose the combination of learning from accomplished marine scientists and having French cuisine in the same time was the epitome of cruise experience for me. And voila – my wish was granted when one of the PI of this expedition, Karin Sigloch, kindly invited me to take part not only in a cruise on a French vessel, but also to experience an amazing adventure: peering into the deep oceans and then into the Deep-deep earth!

In less than one week we crossed fracture zones, mid-ocean ridges and volcanic edifices going through the evolution of the ocean floor like a quick tour from Rome, to Verona and than Milano, from ancient history to modern era. OBS deployments are our daily source of joy once they are delivered to the sea by a team of careful parents who want to make sure they prepared their children for their one-year foreign experience. The joy will be even greater next year when these children will come back full of knowledge from their year spent on the sea bottom – and then the mysteries of the Deep Earth will be finally revealed.
But for now we enjoy the rich life on boat –and the French cuisine, and the almost constant 22-23 degrees air temperature (water temperature is even better-but for various reasons we cannot enjoy that), and gorgeous sunsets and a bunch of amazing people.

The Marion Dufresne community is wonderfully diverse: the learned professors and senior scientists are happily playing basketball with the enthusiastic students – that is, of course, when their presence is not required for solving the scientific tasks, the multi-origin crew (among them French, Malgasy and Romanians) try to run smoothly the life on boat, and French (and English, and German, and some other languages) conversations around the table (whether in the laboratories, restaurant or seminar room) revolve around every imaginable subject – from seismology to marine biology, from George Clooney to GO, and from chili to best military airplanes.

My sunny life for the past two weeks had only one shadow: I missed the only lunch that served éclairs for desert!

To drop or not to drop?

Written by Karin Sigloch on Thursday, 04 October 2012. Posted in Cruise 2012

4 October 2012

Annotated map describing an OBS deployment (station RR17). (Read more bellow)

Among our most crucial decisions is where on the seafloor to drop our seismometers. Geometrically, the task is not unlike dropping them from an airplane at 3-6 km altitude, hoping that they will land in a suitable spot. Some luck is needed, because the seafloor is not mapped down to the meter scale, and because ocean currents can carry the OBS away laterally by several hundreds of meters before they reach the seafloor.

However, careful preparation can maximize the chances of a successful landing. The most basic requirement: the instrument should be recoverable when called to return to the surface – that may not be possible if it landed in a crevasse or tumbled over on a steep slope. Hence we seek out relatively flat spots of at least 1 km2 area. Such places can be found even in (underwater) mountain ranges, but dropping an OBS there requires more preparation than on a vast abyssal plain.

The other morning we had a challenging case, a targeted OBS site on the steep flank of the Mascarene plateau. The only prior bathymetry information came from "Sandwell", a jargon referring to maps extrapolated from measurements of gravity satellites – very smoothed and blurry sea-scapes compared to reality, but much better than nothing (see annotated map). "Sandwell" suggested a little flat embayment in the plateau flank, but as we approached, the highly-resolving ship bathymeter gradually revealed a steeply incised canyon, 2800 m beneath the surface. No sediments to flatten out even a small area. We collectively pondered the evolving scene, and imagined mud avalanches rushing down the canyon channel. Fact or fiction? No way to tell. It seemed unwise to drop the OBS there.

With not many options available, we targeted a small protruding ledge a few miles up-flank on Sandwell's map. The approach was steep and unpromising, but suddenly sediments started showing up on the screen of the sediment sounder. The saddle area turned out to be narrower and shifted compared to the Sandwell prediction, but 1.5 miles wide and reasonably flat seemed lucky under the circumstances. We dropped the OBS above the likely equivalent of an Alpine meadow, bounded by a steeply incised mountain stream, perhaps with bottom-dwelling fish instead of grazing cows. It had taken us two hours, but had also satisfied our curiosity. Expert bathymetrist Jérôme summed it up: "Interesting – so that's what a canyon may look like for Sandwell."

* Picture Caption : 

Annotated map describing an OBS deployment (station RR17). Before our arrival, we had only the blurry bathymetric information that fills most of the picture (“Sandwell”, extrapolated from gravity satellite measurements). In real time, we replaced a ~10 km wide swath beneath our ship track with the ship’s own, more highly resolving measurements (top left to bottom right). It revealed that the seafloor in this area was not smooth at all – it took some cruising to find even a small flat spot.

Floating seminar

Written by William Jason Morgan on Thursday, 04 October 2012. Posted in Cruise 2012

4 October 2012

Detailed bathymetry measured by our ship has been laid over a coarser, pre-existing deep-ocean map. Note the canyon that appears on the highly resolved swath. The swath is about 10 km wide, the canyon is located around 3000 m depth.

One of the more interesting aspects of a research cruise is the 'floating seminar' atmosphere. I don't mean the daily afternoon presentations in the conference room by one of the cruise participants, as interesting as they are, I mean the daily interactions of persons with various specialties from various institutions all focused on a single research project. Seeing how the ocean bottom seismometers (OBSs) are assembled, tested, deployed over the side (gently!); having discussions of what can go wrong, tales of past mistakes, improvements being made all give one a better understanding of how a seismic experiment is planned and executed far beyond what one can get from reading journal articles of OBS results.

Another center of activity and discussion is the monitor screen that displays each 'sweep' of the incoming bathymetric data. The 'multibeam' bathymetry of the Marion Dufresne has acoustic sensors that look not only straight down to the seafloor but also are aimed outward to receive echos from many angles away from straight down. Then the return echos of the many sensors are put together in the system's computer, and a 'swath' of bathymetry is produced. The moving ship results in a ≈5-km-wide ribbon of seafloor depths mapped, analogous to laying out a series of aerial photographs for land mapping.

The general locations of each OBS site were selected when the experiment was planned, but the precise location for a 'drop' is made while looking at the bathymetry collected at the site. At this time, many eyes gather in the lab around the bathymetric screen -- all looking for that perfect flat, not too rocky, not too steep spot on the ocean floor. Lots of murmur in the peanut gallery as Karin and Guilhem make the final choice -- sometimes the initial 'X' is abandoned and a 'better' place several kilometers away is selected instead.

The bathymetric screen showing the swath of bathymetry collected as we steam from drop-point to drop-point is a constant focus of interest. Many so-called "seafloor canyons" have been seen in the swaths. These features are tens of meters deep and hundreds of meters wide; they are commonly made by avalanches on the steep slopes of continental shelves which create a fast moving mixture of water and suspended sand which cuts away the flat mud on the seafloor much like a river cuts away land surface. Near continents, such 'canyons' can be traced for hundreds of kilometers; the source here mid-ocean would most likely be collapse of the slopes around the carbonate banks and islands of the Mascarene Plateau. Our cruise isn't mapping them -- following them from beginning to end -- but we have crossed and noted perhaps a half-dozen on our zig-zag path from site to site and wonder collectively where and how each may have originated.

And last night the sky was brilliant; a bright Milky Way and the bow of the ship pointing directly toward the Southern Cross.

“It’s déjà vu all over again”

Written by Karin Sigloch on Monday, 08 October 2012. Posted in Cruise 2012

6 October 2012

“It’s KUMing home” – was it them who told the dock workers that the Marion Dufresne would be back in port?

"It's kuming home" -- Was it them who gave away the Marion Dufresne's return to port?


Halfway through the experiment, we were going to stop briefly in La Réunion on October 9, in order to pick up more colleagues and material. And guess what, yesterday the dock workers announced a strike for that day. No joke. This time a nationwide general strike of harbor workers and others.

The human mind tries to make sense of things. The first strikes in 10 years, and both on the only days that we need the dock workers? They must have been missing us, our friends from the dock – longing for another rendez-vous at the harbor gate, no doubt. Has nobody else been talking to them since we left? Who has leaked the plans for our stopover, and how do we plug this leak, given that we'll have to return to port once more at the end of the cruise?

But they blundered, this time by giving us more than 24 hours notice. Yesterday was spent with frantic phone calls and deliberations, a scramble to advance our port visit by one day: to rush in our colleagues from Europe for Leg 2, to accommodate the people leaving, and to design a new deployment route that minimizes the loss of time. Plans for this counterstrike are well advanced: Rendez-vous in Le Port on the 8th – in full working gear!

The whale and the butterfly (digression about rounds on the water)

Written by Jérôme Dyment on Monday, 08 October 2012. Posted in Cruise 2012

7 October 2012

On Rhum-Rum, we are not doing rounds in the water...  but nice drawings indeed!

Of us, marine geophysicists, who wander on the oceans, looking for indices to better understand how the seafloor forms, ages, and disappears, some are saying that we are doing rounds on the water. It is untrue, indeed! A short glimpse to the route map of cruise Rhum-Rum - routes achieved during the first leg, routes to be done during the second one - clearly shows that, if we do accumulate some mileage, it is certainly not doing circles but much more complicated figures, which await patiently an improbable Sigmund Freud to decipher their deep meaning, their psychoanalytic signification. This aspect appeared to me when, just after my PhD thesis - otherwise said in the Middle Age - I boarded the first Marion Dufresne for cruise MD67. Possibly affected by our short stop in Kerguelen Island when approaching the study area, our path was drawing a giant penguin superimposed to the structures of the Kerguelen Plateau and the Enderby Basin. Years later, when I was leading cruise Magofond 3 on R/V Suroît south-east of the Canary Islands, I rapidly noticed that our tracks were making a big M then a smaller A - we did not reach the end of the word, but were then making deep-towed magnetic profiles across the Cretaceous Quiet Zone to try to unravel one of the greatest remaining enigmas of geomagnetism. And today, finishing Rhum-Rum Leg 1, the two wide loops that we made to the East - almost touching Rodrigues, and Mauritius twice - and to the West - in a rather shy approach to the Big Island of Madagascar - let me think of the (truncated - we lost 6 days!) wings of a giant butterfly (Figure 1), whose body would be made of the inner circle of ocean bottom seismometers that we consciously dropped all over around La Reunion Island... Should we imagine the caterpillar, moving up from the deep Earth mantle with ascending currents of the inferred plume, cocooning in the heat of the Fournaise then metamorphosing to butterfly and taking advantage of our cruise to escape, like an allegory of the Truth coming out of the well - I wouldn't dare to say in what apparel!

As I write Leg 2 remains to be done, and I will unfortunately not be there to contribute more than through some maps - again - left onboard to the best use of the chief scientists. I already see, in the projected tracks, the shape of a whale (Figure 1), its noose on the Rodrigues Triple Junction - this peculiar point where three mid-ocean ridges meet. The whale's front follows the Central Indian Ridge, its mouth would be located in that small area of the Southwest Indian Ridge where eight ocean bottom seismometers will be deployed very near to each other - may be to detect a possible raging "baleenache"... Paradoxically, I imagine the dorsal fin on the side without any active ridge ("dorsale" in French), in the Madagascar and southern Mascarene basins, as an indication of other, fossil spreading centers that we would not have properly detected yet.

Now you know why I entitled this essay "the whale and the butterfly". It is open to analysts and other psychiatrists, professional or not, to further investigate the matter - delirium is not unusual in geosciences!

End of Leg 1 -- heading south now

Written by Karin Sigloch on Thursday, 11 October 2012. Posted in Cruise 2012

8 October 2012

20121009 01 EquipeLeg1 J2Z0192

 The first leg of our cruise ended today. As the Marion Dufresne approached La Réunion in the morning, visibility of the 3000 m high volcanic island was excellent. Our dream is to image equally clearly to 3000 km depth. (Photo: Nicolas Villeneuve)

 

20121009 02 SAM 0968

Entering Le Port and relieved to see that the large harbor machines were working. We had arrived one day early just to avoid another harbor strike tomorrow.


20121009 03 SAM 1005

 In the early evening, we had to say farewell to 11 colleagues, who had been interested mainly in exploring the region around the Mascarene islands. Leg 2 will consist of a 7000 km long round to the far south of the islands. Six new colleagues came onboard, among them the French OBS team with another 9 seismometers.

 

20121009 04 MD depart SAM 0998

All unloading and loading got done in time. We left the harbor late in the evening, happy to get back onto the ocean.

 

 

A life after the Marion Dufresne?

Written by Maria Tsekhmistrenko on Sunday, 28 October 2012. Posted in Cruise 2012

25 October 2012

The last day has broken. Only a few hours left before we have to leave the ship. For the first time in weeks we are going to feel firm ground under our feet. We are leaving the ship, which was like home for us, though for a relatively short time.

 SAM 2233

Over the past days, I wistfully I enjoyed my coffee on my favorite outlook spot on the deck. I never got bored of the beautiful view of the ocean, and every day I enjoyed it more. While sitting here, I remembered many moments on this ship:

Jeans “plat au fromage”; Patrik, our best friend behind the bar; Chris trying hard to find some people to play baby foot with him after each meal; Henning’s long way down to get his “big, black, bad” – coffee; Karin and Gulihem trying to find the perfect deployment point for the OBS; Sacha’s tireless night shifts, which helped to sit out the long hours; Heiner playing Guitar; Oliver’s daily search for the next seminar speaker; the united march of the officers to the dinner table; the deployments, the Marion Dufresne, the ocean…

Thanks to all of you taking part in the cruise (LEG 1 and 2). Thanks for the unbelievably great, exciting, educational, fascinating and definitely unforgettable time on this ship. 

Meteor and Marion Dufresne, an unexpected rendez-vous in the Indian Ocean

Written by Guilhem Barruol on Sunday, 03 November 2013. Posted in Cruise 2013

2 November 2013, Guilhem Barruol

 

 The Marion Dufresne vessel that allowed us to deploy our ocean bottom seismometers in Oct-Nov 2012 was scheduled to leave La Réunion last Wednesday to make its rotation toward the Austral islands: Crozet, Kerguelen, Amsterdam and St Paul.  A technical problem did not allow the Marion to leave La Réunion on time and she finally departed on Saturday morning going southward to Crozet island, the first destination before Kerguelen. The probability that the two vessels that actively took part in the RHUM-RUM experiment could meet in the Indian Ocean was obviously very small due to the size of the Ocean but also due to our way of progressing in zig-zag from station to station with the vessel Meteor. 
This Sunday morning at 5 o'clock, the Meteor reached the position of the station RR24, the southernmost of our first leg. At  sunrise we discovered the Marion Dufresne at the horizon, she was approaching us. At 6:30, we were at about 5 miles from each other, and no doubt that the Marion crew has seen us as well as we have seen them. A really unexpected meeting in the sunrise light!
Other - and ultimate - coincidence: the station RR24 at which we met was the last of the 57 OBS deployed last year with the Marion Dufresne and that we celebrated on the back deck of the Marion on Oct 22, 2012. Be always careful with the probability!

We wish the Marion a good way for its Austral rotation!

End of second RHUM-RUM cruise in La Réunion

Written by Guilhem Barruol, Karin Sigloch on Saturday, 07 December 2013. Posted in Cruise 2013

4 December 2013, Karin Sigloch & Guilhem Barruol

 

Wednesday, 4 December at 5:00 in the morning, La Réunion Island is lying ahead of us in the first daylight -- our cruise is ending here.

The "Marion Dufresne" arrived in Le Port together with us.

We made a fuel stop in Mauritius yesterday. During our overnight transit to La Réunion, the research vessel Marion Dufresne had stayed by our side the entire time. They too had been filling their tanks on Réunion’s enterprising sister island, but for us, the unexpected company of “Le Marion” during our last cruise night meant a bit more. It was with this French ship that we began our experiment and deployed our seismometers 14 months ago. Being accompanied home to Le Port by Le Marion, with all OBS recovered onboard the German Meteor, gave a beautiful sense of closure.

Things are moving in European marine geophysics!

Thank you very much to the science party of cruise M101, and to those who will now work hard on the data, in order to illuminate one of the darker corners of the interior of our beautiful planet.

And thank you very much to the crew of the Meteor for their dedication, professionalism, and good humor at all times of day.

Vielen Dank und auf Wiedersehen!

Karin & Guilhem

 

Science team of cruise M101, Leg 2.