Day 23 (07Jul2008)

Location: 49º06’N – 11º32’W

Weather: Cloudy

Wind: 13 knots

Dear colleagues,

Sadly, our journey is quickly coming to an end. Although we have thoroughly enjoyed ourselves, and are sad to pack up our things and say our goodbyes, we are also excited to see our families and friends back on 'terra firma'. Together, we have learned and experienced many new things that we hope to incorporate into our classrooms. We also hope to disseminate the information to other teachers so that they might also share the experience with their students. Including samples of authentic science is a key component of science instruction.

The whole group on the Marion Dufresne

We are now sailing back towards the South, not far from the Irish coast. Yesterday we prepared our mail with Captain F. Duchene, and included many different hand stamps. Also yesterday Catherine Kissel, the chief scientist of the mission, summarized the results of the cruise. On the mission 10 Casq cores, 13 Calypso cores, and 4 Multicores, (together 483m of cores) have been taken (although not all of these were successful). So far we have traveled 5000 miles. Another important piece of information presented was the amount of time spent at each site (for surveying, coring, and transit).

For each coring site, magnetic susceptibility and lightness, or color reflectance, were correlated between the Calypso and Casq cores.

Lightness gives us an early, and very general, indication of the origin of sediments. Lighter sediments are generally from pelagic sources, and darker sediments are generally from terrigenous sources. Lighter sediments typically indicate interglacial periods, while darker sediments typically indicate glacial periods. Many further analyses will be conducted after the campaign, but it may take a considerable amount of time these analyses to be fully understood and published. Overall, however, the goals of the AMOCINT campaign itself have already successfully been met.

The teachers at sea

In the coming days we have many tasks to accomplish to get ready for our arrival in Brest. Tomorrow we will take two or three more cores south of Ireland and west of Brest, which we must process quickly. All available data must also be turned in for the scientific report, and all of the samples must be carefully packed. The ship must also be cleaned for the "BREST 2008" festival, a naval festival which only takes place once every four years. During the festival a delegation of the French minister of education will visit the R/V Marion Dufresne and Hélder and

Carlo will inform them about the Teachers at Sea program.

We thank you very much for following our journey through our emails.

We hope that you will include examples from this research cruise when discussing how science is done in your classroom. We wish you and your students a very happy summer holiday!

Sincerely,

Hélder - Gertrud - Catalina - Jean - Angela - Carlo

Day 20 (04Jul)

Location: 65° 50' N - 4° 5' E

Weather: Sunny

Wind: 21 nds

Hello everyone!

We are in the last week of our journey, and we still have a large portion of the work of the mission to complete. We are currently in a critical site in the Vøring Plateau, where we have three coring sites and will take multiple cores of different types at each site. The weather is beautiful here off the coast of Norway, and the forecast for the time we will spend here looks very pleasant! The sea is calm and brilliant with the sunlight reflecting off of it. It is strange for most of us to have full sunlight throughout the night. This should make the 4-8am shift a bit easier for Catalina, Gertrud, and Hélder.

Sunbathing in the Artic

We will continue with some of the information that was presented in lectures during transit time (since we are resuming work we will not have more lectures until the next transit period). PhD student Charline Marzin presented a series of two talks about climate modeling. Climate modeling is absolutely necessary to understand what changes we might expect to see in our climate in the future, and also what implications these changes may have. Also, modeling allows us to identify factors that are not changing in the way we would expect.

Through identification of phenomena that are not well understood researchers can identify areas for future research.

When building a climate model, researchers must find a balance between the level of resolution of the model, the time extent of the model, and the computing time required to run the model. Climate conditions are affected by many factors, and are thus very complicated. The greatest source of uncertainty, however lies in future factors that we cannot predict, such as economic factors, emission levels, human population, etc.

In the second talk Charline focused on the findings of the most recent IPCC* report and her own research. This IPCC report found it to be very likely (In the past IPCC report it was just "likely") that recent rapid climate change is due to increased greenhouse gas (and especially CO2) emissions.

Charline working on a Calypso core

Charline is using climate modeling to better understand monsoons, and specifically what changes may take place in the monsoon cycle due to rapid climate change. PhD students Laure Resplandy and Stefano Bonelli also presented information about their modeling projects. Stefano works on coupled climate-ice sheet modeling, in order to simulate the topography of past major ice sheets in both Northern and Southern hemispheres. This implies consistency between the simulated climate and ice sheets, including the main feedbacks between these components.

Laure is modeling the distribution and transport patterns of areas of high productivity in the ocean at a high resolution. Her topic is particularly interesting because it involves both physics and biology.

Hearing all of these talks involving modeling gave us an idea of the importance of modeling and the breadth of the field.

Thank you again for following along on our journey!

Sincerely,

Catalina-Hélder-Gertrud-Jean-Angela-Carlo

* IPCC : Intergovernmental Panel on Climate Change

Day 18 (2 Jul)

Location: 64º32'N - 05º56'W

Weather: sunny

Wind: 14 knots

Dear Teacher Colleagues,

Today, as we prepared to cross over the Arctic Circle, we are nearing the end of a long transit period between the Charlie Gibbs fault and the Vöring Plateau. This provides us with more time to learn more about the specific scientific projects that are being conducted in concert with the goals of this mission. Both the chief scientists and the graduate students have provided us with very interesting lectures.

A complete rainbow during transit between the Charlie Gibbs fault and the Vöring Plateau

A chief scientist or a PhD student presented first; and then a masters student. These lectures help us to more clearly understand the goal of the AMOCINT Project. The masters students presentations include research covering other areas of oceanographic, biological and geological research. These presentations are also a good opportunity for the students to practice presenting their research.

First, co-chief scientist Kikki (Helga) Kleiven presented information about the overall goals of the AMOCINT project (which focus on reconstructing past deep ocean circulation patterns during interglacial periods to better understand how patterns may change in the future), general information about oceanography, ocean sediments, circulation patterns, and rapid climate change.

Two days ago, chief scientist Catherine Kissel explained the importance of the past vectorial variation of magnetic field as stratigraphic tool. The paleomagnetism record can be used to determine leads and lags in the climate record, and accurately correlate climate records from sediments and ice cores. The Earth's magnetic field generated in the core can be measured on the surface. The magnetic field is global and independent of climate, and can be measured in different materials. The study of paleomagnetism in lava flows leads to the reconstruction of past magnetism, and the magnetism of sediments gives information about their sources and environmental changes.

A PhD students Charline Marzin, along with two other PhD students, Stefano Bonelli and Laure Resplandy, also presented a series of two talks about ocean and climate modeling, as well as the recent IPCC report. We will discuss these topics further in the next email.

We crossed the polar circle last night!!!

Thank you for your continued interest!

Sincerely,

Helder-Gertrud-Jean-Catalina-Angela-Carlo

Dia 17 (1Jul)

Coordenadas: 66˚10’ N 0˚3’ E

Olá a todos!!!

Hoje voltámos a ter um dia com um Sol resplandecente. Obviamente as temperaturas foram igualmente mais agradáveis. É incrível a forma como o tempo muda de um dia para o outro. Não deixa de ser curioso que, sendo esta missão oceanográfica dedicada ao estudo das alterações climáticas, possamos constatar quão variável é o estado do tempo no curto prazo.

Durante a manhã tivemos a oportunidade de ver a equipa da Universidade de Kiel (Alemanha) a realizar a amostragem de alguns testemunhos de sedimentos cortando-os em fatias de 1 cm. Os sedimentos eram depois colocados em frascos, devidamente catalogados, para mais tarde serem submetidos a análises isotópicas (δ¹⁸O e δ¹³C).

Amostragem de um testemunho de sedimentos Calypso

A seguir ao almoço efectuámos uma visita à sala das máquinas onde se localizam os dois motores eléctricos, com uma potência de 3000 kW cada, que, para além da propulsão até uma velocidade máxima de cerca de 16 nós, permitem que o navio se mantenha na mesma posição durante a realização das operações de carotagem. Pudemos ainda ver o conjunto dos três geradores a diesel que têm uma capacidade de produção de 8250 kW de energia eléctrica.

Motor eléctrico do Marion Dufresne

Motor eléctrico do Marion Dufresne

No entanto, o que mais me impressionou, foi o sistema de dessalinização de água do mar que tem uma capacidade para tratar cerca de 20 toneladas de água por dia, permitindo que não haja falta de água a bordo. Assim, podemos tomar vários duches por dia de forma a vermo-nos livres da lama com que nos sujamos quando trabalhamos com os testemunhos de sedimentos no convés.

Durante a tarde assistimos ainda a uma segunda palestra sobre as propriedades magnéticas dos sedimentos. À noite festejámos antecipadamente a passagem do Círculo Polar Árctico, pois amanhã, ao chegarmos ao planalto de Vøring, voltaremos a realizar perfurações e ao trabalho por quartos no convés (…). Espero que em breve possamos assistir ao fenómeno do Sol da meia-noite.

Dia 16 (30Jun)

Coordenadas: 63˚12’ N 10˚29’ W

Olá a todos!!!

Hoje o mar esteve muito agitado. Creio mesmo que foi o dia em que o navio mais balançou desde o início do cruzeiro. As temperaturas voltaram a diminuir para valores abaixo dos 10 ˚C.

Vagas no alto-mar a caminho do Círculo Polar Ártico

A manhã foi dedicada essencialmente ao descanso (deu para dormir até um pouco mais tarde do que o costume) e ao exercício físico. Voltámos a jogar badmington e também ténis de mesa. Acreditem que com o navio a balançar é bem complicado praticar desporto.

Jogando badmington a bordo do Marion Dufresne

A seguir ao almoço voltámos a assistir a uma palestra sobre modelação climática. Deu-se ainda início aos preparativos da cerimónia de passagem do Círculo Polar Árctico.

Após o jantar, para quebrar a rotina, houve uma sessão de cinema na sala de conferências em que temos assistido às palestras.

Day 16 (30Jun)

Location: 62° 11' N - 13° 48' W

Temperature: 10°C

Wind: 31.8 Knots - 335°/North

Hello fellow teachers, Thank you for continuing on our journey with us!

Today we are on the second day of a 5 days transit up north. Right now we are somewhere between Iceland and the Faeroe Islands. The next site we are going to core are the Voeringer Plateau. Until now we have taken 8 Calypso cores, 6 Casqs and only one Multicore, some failed unfortunately.

In order for an oceanographic campaign to be successful many people must collaborate on many levels. Research of this type requires a tremendous amount of planning and manpower. For instance, the AMOCINT project is spearheaded by four groups. Each group focuses on one or more specific geographic areas, but for the most part they conduct similar and/or complementary analyses on the sediments. The group from the University of Kiel is currently focusing on the vicinity of the Açores, The two French groups from the University of Bordeaux and the L.S.C.E. of Gif-sur-Yvette are focusing on the areas of the Charlie-Gibbs Fracture Zone, Gardar strait and the Vöringer plateau.

The Bjerknes Center of Climate from Norway is covering the sites outside West Africa, the Faeroe Islands and also the Vöringer plateau.

Although the group from Portugal (from the INETI (Instituto Nacional de Engenharia, Tecnologia e Inovação) Departamento de Geologia Marinha) is not present on this leg of the cruise, they will take cores around the Portuguese margin on a cruise starting in July. Each group is involved in decisions affecting the mission, however, it should also be noted that the overall goal of the campaign is the same.

We all also must collaborate on smaller levels as well. For instance, we are all organized into watches, or shifts. Gertrud, Hélder, and Catalina are on the 4-8 shift, afternoon and evening, and Angela and Jean have the 8-12 shifts, morning and evening. In order to process the samples properly in the time allotted everyone must do their part and be present for their shift. Our shift groups were organized to allow people from diverse background to work together and get to know each other. Each shift group includes people from different institutions, professions, nationalities, and with different cultural norms, work styles, and languages. This is an example of why it is important for our students to work well together in groups despite differences they might have.

The research effort also involves many people with backgrounds and skill sets other than oceanography. There are many aspects that go into designing and operating coring equipment and a research vessel, as well as planning an oceanographic mission. The crew is largely from France and Madagascar, and is also very diverse, and made-up of men and women from many different ages and backgrounds.

Although what we do on a day-to-day basis before, during, and after the cruise is very different, we are all working towards a common goal. There are many people on the ship from different cultural backgrounds and who speak different languages. Just some of the languages you will hear on a daily basis during this campaign are French, English, Norwegian, and German, but there are many others!

This provides a fantastic learning opportunity. When we discuss the collaborative nature of science with our students, an oceanographic campaign provides a great example!

Thank you again for your continued interest!

Sincerely,
Hélder-Catalina-Gertrud-Jean-Angela-Carlo

Dia 15 (29Jun)

Coordenadas: 60˚42’ N 18˚28’ W

Olá a todos!!!

Hoje atravessámos o paralelo 60… O mar e o vento mantiveram-se calmos ao longo da maior parte do dia. O Sol voltou a brilhar e as temperaturas estiveram um pouco mais agradáveis.

Sendo Domingo a comida foi especial. Como já vos disse as refeições a bordo do Marion Dufresne são uma maravilha. Ao pequeno-almoço tivemos direito a comer uns pãezinhos com passas ainda mornos… Uhm… que delícia! Ainda da parte da manhã, para manter a forma, jogámos badmington, ténis de mesa e andámos um pouco de bicicleta. O almoço incluiu como costume uma entrada e um prato. A entrada foi um Feuillté d’escargots e a refeição principal foi Sanglier des Ardennes com Pommes Paillassons e um Fagot de Haricots Verts acompanhada com um belo Chardonnay branco. Seguiu-se um Plateau de fromages e um Banc d’Opéra como sobremesa. Estava tudo delicioso!!!

Feuillté d’escargots

Sanglier des Ardennes com Pommes Paillassons

Banc d’Opéra

De tarde, como estamos em “trânsito” entre estações, e não temos testemunhos de sedimentos para tratar e analisar, assistimos a uma palestra sobre o campo magnético terrestre e as propriedades magnéticas dos sedimentos.

O resto da tarde foi dedicado à lavagem de roupa e descanso. O jantar também estava muito bom. Seguiu-se mais uma celebração de um aniversário. O momento alto do dia foi quando por volta das 23 horas surgiu um belo arco-íris no céu.

Arco-íris ... às 23 horas

Sim… o Sol ainda brilhava, isto apesar de ainda não termos chegado ao Círculo Polar Ártico. Mal posso esperar para ver o Sol da meia-noite…

Pôr do Sol

Dia 14 (28Jun)

Coordenadas: 57˚26’ N 27˚54’ W

Olá a todos!!!

O mar e o vento mantiveram-se calmos ao longo da maior parte do dia. O Sol voltou a brilhar, mas as temperaturas mantêm-se baixas. Chegámos no final da manhã à zona da estação de amostragem de Gardar, localizada a sudoeste da Islândia, e já durante a tarde foi lançado ao mar o equipamento de carotagem Calypso.

O tubo Calypso

O testemunho de sedimentos obtido não foi tão comprido quanto o esperado devido a uma “drop stone” que impediu o fecho do sistema de retenção dos sedimentos existente na ogiva. Perderam-se cerca de 30 metros de material e o testemunho de sedimentos ficou muito alterado, tendo sido recuperados apenas cerca de 23 metros. No final do dia zarpámos em direcção ao planalto de Vöring (onde serão recolhidos sedimentos em três locais) e, durante o turno das quatro às oito da manhã, terminámos o processamento do testemunho de sedimentos recolhidos em Gardar.

Day 13 (27 Jun)

Location: 54º 32’N – 32º 56’W

Weather: Cloudy and rainy

Wind: 28 knots

Coring has just been completed at two sampling locations in the Charlie Gibbs fracture zone. The exact location of the sampling sites was unknown because this area has not been surveyed before. Indeed, although the oceanographic vessel Charcot took a short core in this area in 1977, at that time there was no GPS technology, so the position was imprecise. Therefore, time for surveying was needed before coring. Through the use of previously existing bathymetric maps and the multi-beam technology available on the Marion Dufresne, the location was found more easily than expected at the first site. A longer survey was needed for the second, shallower site.

Map with the coring stations location near the Charlie-Gibbs fracure zone.

The interest of coring in this area is that it is located on the path of both the warm surface waters going northward (north Atlantic drift) and the dense cold deep water mass coming back southward from the Nordic seas.

Once we arrived at the Charlie Gibbs fracture zone, we took a Casq core, but some of the sediments spilled out the top. Then, sediment in perfect condition was collected in a 35.48 meter long Calypso core. An additional successful Casq core completed sampling at the first site.

At the site the wind was very strong, and there were large waves, which made the coring very difficult. Also, the temperature was quite cold, which made the work uncomfortable and exhausting at times. The weather conditions even made the working conditions risky, as we unfortunately saw when Gertrud fell on slippery steps. She bruised her ribs, but is in good spirits—and is currently processing data!

The Marion Dufresne now continues on to the second location in the Charlie Gibbs zone in hopes of better weather. The survey allowed the research team to make a more extensive bathymetric chart of the area.

In fact, the weather conditions did not improve at the second location, but became more challenging (the wind was at a speed of 45 Knots). A Casq core, and then a Calypso were attempted, but the latter had little success (the Calypso core was only 7.27 meters). Therefore, last night the first location was again investigated in hopes of obtaining a longer Calypso core. When we arrived the weather was much improved, with calmer seas, so a long Calypso core was attempted with the approval of the captain. Everybody was extremely pleased to bring a 52.45 meter Calypso core on deck about 4 a.m. last night! Overall, although we experienced some set-backs, the coring efforts were highly successful in the Charlie Gibbs fracture zone.

Now that the Charlie Gibbs fracture zone work is successfully completed we will continue North to our next sampling site (the “Gardar” site). We will arrive tomorrow afternoon, and should have some news for you in our next email—thank you for your continued interest!

Your fellow sea-faring teachers,

Hélder - Jean - Gertrud -Catalina - Angela - Carlo

Dia 13 (27Jun)

Coordenadas: 52˚70’ N 35˚94’ W

Olá a todos!!!

Esta madrugada, ao acordar, fui surpreendido com a notícia de que tínhamos regressado à primeira estação da região da fractura Charlie-Gibbs e que estavam a puxar para o convés o equipamento Calypso. À segunda tentativa conseguimos recolher o testemuho de sedimentos mais comprido, obtido até ao momento nesta campanha, com cerca de 53 metros. Tivemos muito que fazer ao longo do dia…

O mar e o vento estiveram mais calmos, mas as temperaturas continuaram baixas (com máximas entre 8 e 10 ˚C) ao contrário das temperaturas elevadas que se têm registado no nosso país.

Após a equipa que lida com os equipamentos de carotagem ter colocado o tubo de aço do sistema Calypso no convés e retirado o tubo de plástico do seu interior o seu trabalho terminou. A partir dali entrámos nós em acção. Entre as quatro e as oito da manhã tivemos que cortar o tubo de plástico, que contém os sedimentos, em secções e transportar cada uma delas até ao local onde as amostras são tratadas. Hoje foi seguramente o dia em que tivemos mais trabalho. Quando o nosso turno regressou ao convés às quatro da tarde ainda havia tubos para limpar e identificar. Para além disso ainda tivemos que cortá-los em duas metades (uma para arquivo e a outra para analisar e estudar), catalogá-las e empacotá-las.

Abertura de um testemunho de sedimentos Calypso

Os sedimentos da metade que é analisada a bordo foram descritos usando-se um formulário que permite recolher informações relativas à estratigrafia, espessura das camadas, litologia e estruturas sedimentares, textura (alguns dos cientistas chegam mesmo a provar os sedimentos de forma a descrevê-la), conteúdo fossilífero e perturbações resultantes do manuseamento das amostras.

Descrição de um testemunho de sedimentos

Para além desta descrição qualitativa os testemunhos de sedimentos foram analisados no Multi Sensor Track (MST) a que já fiz referência. O MST é um conjunto de instrumentos, localizado num contentor, que permite medir algumas propriedades físicas dos sedimentos recolhidos. Estas propriedades são a velocidade de propagação das ondas P, o diâmetro e temperatura do testemunho de sedimentos, a atenuação de radiação Gama e a susceptibilidade magnética. Os sedimentos foram ainda fotografados e analisados por um espectrómetro.

Análise de sedimentos no MST

Depois de tudo isto terminámos o turno e pudemos finalmente ir jantar, descansar e dormir uma noite de sono completa, pois iniciámos um período de “trânsito” de cerca de 24 horas, rumo a Nordeste, até à zona de Gardar.

Dia 12 (26Jun)

Coordenadas: 53˚11’ N 36˚49’ W

Olá a todos!!!

O frio veio definitivamente para ficar… O mar entretanto, devido ao vento forte (cerca de 50 nós) que se fez sentir, esteve muito agitado o que dificultou os trabalhos de pesquisa dos novos locais a perfurar e a colocação do equipamento de carotagem na água. Continuámos ao longo de todo o dia a pesquisar diferentes locais na região de fractura Charlie-Gibbs.

O interesse em recolher sedimentos na zona da fractura Charlie-Gibbs tem a ver com o facto de a corrente de água profunda do Atlântico Norte passar por ali e permitir a deposição uma grande quantidade de sedimentos naquela região.

Locais de recolha de sedimentos na zona da fractura Charlie-Gibbs

Apesar de estar prevista a recolha de sedimentos em mais duas estações, as pesquisas efectuadas permitiram apenas encontrar mais um local adequado para o lançamento dos equipamentos de carotagem. O mar acalmou um pouco, pelo que no fim do dia ainda ali se conseguiu recolher mais testemunhos de sedimentos com dois dos tipos de equipamento de carotagem a bordo do R/V Marion Dufresne: Calypso e Casq.

Espera-nos um longo período de tempo dedicado ao tratamento das amostras de sedimentos recolhidas. Amanhã vou descrever o tipo de análises preliminares a que os testemunhos de sedimentos são sujeitos a bordo.

Dia 11 (25Jun)

Coordenadas: 52˚51’ N 36˚30’ W

Olá a todos!!!

Hoje o mar esteve bastante calmo, mas a temperatura não passou dos 11 ˚C (…). Foi um dia de trabalho contínuo para todos os turnos.

Após termos chegado à zona da fractura Charlie-Gibbs, durante a madrugada, procurámos o melhor local para realizar a recolha de sedimentos. Uma vez concluída a pesquisa lançou-se à água o equipamento de carotagem Casq na primeira estação de amostragem.

Recolha de amostras no tubo de carotagem Casq

O primeiro testemunho de sedimentos recolhido permitiu obter uma boa sequência de materiais, depositados em períodos com diferentes condições climáticas, que eram facilmente identificáveis pela cor bege (interglacial) e cinzento-escuro (glacial).

Sedimentos depositados em diferentes períodos climáticos interglacial - e cinzento-escuro - glacial).

Nestes sedimentos foram encontradas rochas designada por “dropstones” que foram transportadas desde altas latitudes por glaciares que ao fundir permitiram a sua queda no fundo do oceano.

Dropstone

Outro aspecto interessante deste testemunho de sedimentos foi a possibilidade de identificar depósitos turbidíticos, que se caracterizam por ser mais grosseiros na base e mais finos no topo, bem como uma camada bastante rica em vestígios de diatomáceas.

Turbiditos

Foram ainda lançados os equipamentos de carotagem multi-corer, cujos tubos regressaram vazios, e Calypso que regressou ao convés sem qualquer problema e cheio de sedimentos.

Dia 10 (24Jun)

Coordenadas: 52˚01’ N 35˚05’ W

Olá a todos!!!

Hoje o mar esteve bem mais calmo… e o Sol voltou a brilhar! A temperatura do ar tem baixado à medida que nos vamos deslocando para Norte. Ontem a temperatura máxima foi de 20 ˚C e hoje diminuiu para 12˚C.

A manhã foi dedicada a recuperar da festa que houve ontem a bordo para celebrar quatro aniversários que decorreram nos últimos três dias. Durante a tarde voltámos a assistir a uma palestra sobre os fundamentos da modelação climática.

O ponto alto do dia foi quando a Marie-Hélène Castera avistou uma baleia. Segundo a co-chefe da missão Kikki Kleiven é provável que avistemos mais baleias à medida que nos deslocamos para Norte. Se isso acontecer espero conseguir tirar algumas para partilhar convosco.

Entretanto, como vos prometi ontem aqui ficam as descrições dos restantes equipamentos de carotagem que temos usado a bordo do Marion Dufresne.

Sistema Casq

O sistema Calypso square (Casq) com cerca de 12 metros de comprimento não permite recolher testemunhos de sedimentos tão longos quanto o sistema Calypso, mas permite obter sequências sedimentares não perturbadas. Durante as operações de carotagem o tubo, com um formato quadrado (25cm x 25 cm), desce lentamente (sem queda livre) até ao fundo do oceano e penetra os sedimentos sem os movimentar. A grande superfície dos testemunhos de sedimentos obtidos com este sistema de carotagem permite estudar melhor a textura e estruturas sedimentares.

O sistema multi-corer usado nesta missão oceanográfica permite recolher amostras de sedimentos junto à interface com a água. É formado por uma estrutura metálica e quatro tubos de plástico com cerca de 50 cm de comprimento e 10 cm de diâmetro. Os tubos penetram lentamente nos sedimentos e a recolha das amostras termina ½ metro após o equipamento atingir o fundo do oceano. Este equipamento é usado em águas pouco profundas e quando as correntes oceânicas o permitem.

Sistema multi-corer

Dentro de algumas horas regressamos ao trabalho e iremos voltar a usar os equipamentos de carotagem que vos descrevi nas três estações de amostragem previstas para a região da fractura Charlie-Gibbs.

Day 9 (23Jun) - Part 2

23 June 2008

Location: 48° 57' N - 33°58' W

Wind : ~17 knots

Water temperature : 14°C

Processing Samples and Data Collection

Bonjour chers collègues!

Today we are still traveling North from the two sampling locations near the Azores islands. This transit period will last 72 hours. Last night and this morning we were experiencing strong winds, and it was very challenging to walk around the ship. Some people were unable to sleep due to the motion, and those who get sea sick are trying to find effective ways to control their nausea.

Selecting the coring site at the Charlie-Gibbs fracture zone

Saturday and Sunday we completed processing the Casq and Calypso cores we collected in the Azores. There are many steps involved in this process-some can be completed here in the laboratory, and others must be completed in the laboratories of the participating institutions after the mission.

The Casq core is usually launched before the Calypso core. When the Casq core is brought on deck we must remove the cover, and then smooth the surface of the sediment with spatulas. We must be careful to smooth the sediment only horizontally and not vertically, or else we will mix sediments from different time periods and contaminate the sample! Then, we place three rows of plastic tubes in the core, flip the core, and remove the tubes with sediment. These samples must all be carefully labeled and packaged for many different types of analysis.

The Calypso core is a steel round metal tube with a thick plastic lining. The crew removes the plastic lining from the metallic tube and places it on the desk for us on metal stands. We then carefully cut the core into 1.5 meter sections. These samples are split into a "working" side and an "archival" side. For all types of cores we must be very careful to label the continuous length of the sediment properly, or else we will not obtain accurate information about the organisms that are present during each geological time period, and we will not be able to successfully reconstruct climate or circulation conditions.

On the ship several qualities of the sediment are described using the visual core description form that includes the summary of stratigraphy, bed thickness, lithology and sedimentary structures,

texture, fossil content and coring disturbances. Sometimes the scientists even taste the sediment in order to describe its texture.

On board the Marion Dufresne there is also the Multi Sensor Track (MST). This is a group of instruments, located in a special container, dedicated to the first measurements of physical properties of sediment cores. These measured properties are P-wave travel time, core diameter and temperature, Gamma ray attenuation and low field magnetic susceptibility. The sediment cores are also scanned and photographed and the visual core proprieties are quantified using a spectrometer.

Machinery cables

These measurements are all critical in order to achieve the goals of the AMOCINT project.

Last night we celebrated four birthdays that have taken place in the last three days. Transit periods are a good time to do this!

Thank you for following our journey, and have a wonderful week!

Your fellow teachers at sea

Dia 9 (23Jun)

Coordenadas: 45˚37’ N 33˚02’ W

Olá a todos!!!

Hoje o mar esteve bastante mais agitado e o navio não parou de balançar todo o dia. Ainda assim, não há sinais de enjoo por estas bandas. Continuámos o nosso percurso rumo à zona da fractura Charlie-Gibbs e, na parte da tarde como não houve perfurações, assistimos a uma palestra sobre alterações climáticas. Toda a gente aproveitou ainda para descansar um pouco.

Como vos disse ontem, vou descrever o equipamento de carotagem Calypso. Trata-se de um sistema que permite obter testemunhos de sedimentos até cerca de 60 metros de comprimento e desenvolvido por Y. Balut no R/V Marion Dufresne. Esta capacidade de recolha de amostras de sedimentos oceânicos faz com que este seja um navio único no que à oceanografia diz respeito.

Sistema Calypso

Após o navio ter fixado a sua posição sobre o local da estação de amostragem o equipamento é colocado na água com ao auxílio de uma grua. O tubo de aço do sistema Calypso, bem como o tubo de PVC com um diâmetro de cerca de 10 cm que está no seu interior e o lastro com 3 a 10 toneladas mantêm-se unidos ao navio através de um sistema de ancoragem por onde passa a um cabo de kevlar, com densidade 1. Esta característica do cabo faz com que, uma vez dentro de água, não adicione qualquer peso ao resto do equipamento e diminua as tensões a que o sistema de recolha do equipamento para o convés é sujeito. Numa das extremidades do sistema de ancoragem é colocado ainda um contra-peso com cerca de 100 quilogramas.

O equipamento desce a uma velocidade de cerca de 1 m/s até próximo do fundo do oceano e quando o contra-peso atinge a superfície o sistema de ancoragem é desbloqueado e o tubo e o lastro continuam em queda livre penetrando os sedimentos. A ogiva colocada na extremidade do tubo é fundamental quer para perfurar como para manter os sedimentos no seu interior. Segue-se a recolha do tubo de carotagem para o convés.

Uma vez no convés o tubo de PVC é retirado do interior do tubo de aço e dividido em secções de 1,5 m. Estas secções são então cortadas em duas metades uma das quais é descrita, fotografada e sujeita a análises preliminares; e a outra metade é embalada de forma a ser preservada e arquivada. Ambas são depois armazenadas em câmaras frigoríficas e levadas para os laboratórios das várias equipas de investigação envolvidas no projecto.

Divisão em secções das duas metades da amostra recolhida

Day 9 (23Jun)

Location: 43° 58' N - 32° 36' W

Temperature: 20°C

Wind: 25.5 Knots - 310°/North

Hello fellow teachers!

After taking cores, there are many things that we must do. For instance, during this time university professors on the cruise give talks about various topics related to the larger topic. For instance, Dr. Kiki (Helga) Kleiven has presented information about marine sedimentation and the properties of seawater and ocean circulation.

The lectures help us to understand more about the significance of studying ocean sediments.

We also visited the bridge where we saw how complicated and sophisticated the equipment necessary to control the ship is. Despite this very technological aspect, the people controlling the equipment are absolutely indispensable. For instance, if the wind is very strong during a coring effort, someone must control the equipment to keep the boat steady manually with a joystick. Otherwise, coring would be impossible during high winds.

We also visited the building housing the winch system and the network of cables necessary for lowering coring equipment to the ocean floor, into the sediment, and back out again. This equipment can withstand an incredible amount of tension, (~ 1.50 x 10⁵ N on the cable to extract the core, but this tension must be reduced to ~ 200 N on the cabledrums) and is designed very carefully for its purpose. For instance, the density of the cable allows it to be weightless in water so that it does not add extra weight to the system. Seeing this equipment made us appreciate how difficult it is to launch and recover the cores. We have had first-hand experience with these difficulties. Our first attempted Calypso core in the Azores was lost due to the bolts failing. We have no idea why this happened. Our second Calypso core in the Azores was very bent. We are unsure what the core hit to cause this to happen. Yet, a little longer than a week into the mission we have already been able to collect many excellent samples which we have already begun analyzing.

That's all for now. Have a nice day!

Your fellow teachers at sea

Hélder - Jean - Gertrud - Catalina - Angela - Carlo

Day 8 (22 Jun)

Position: 38,33° N / 31,15° W

Weather: Light Skies

Temp: 20,8°C

Wind: 12,6Nts

Hello dear fellow Teachers!

We have now reached the Azores and have started coring. First out was a CASQ core at 2024m depth. It takes about an hour or more to prepare the CASQ and then it takes over half an hour to lower it (1m/sec), and finally over an hour to pull it up again (0.2m/sec when still in the sediment and then again 1m/sec). It takes another hour to dismantle it before we start to process the core. It is an interesting procedure to watch. It is a very dangerous and difficult job for the crew members who are actually operating the coring equipment. After the CASQ the Multicore was sent down, and then the Calypso core. However, bad luck hit us and the whole score equipment got stuck in the bottom and was lost. We then transit to another site 4 hours away, where we took a CASQ and a Calypso score. The Calypso did bend this time, but we didn't loose it. We are now on our way to the next site, located in a region called the Charlie-Gibbs fracture zone.

A Casq core

Today we would like to thank you for showing your interest for AMOCINT. We will try to answer some questions that we still haven't covered in earlier emails.

So, why not tell you about the meals onboard? This is a French boat, of course with a French chef. Everything is very tasty and well prepared.

Breakfast: Breakfast is served in a typically French style, with white bread and jam. In addition there is coffee, tea, milk, orange juice and cornflakes. Sometimes there are also leftovers from the night before, like meat. Breakfast is served between 7:00 and 8:30am. Northern Europeans have to adapt a bit, because they are more used to fullkorn bread, muesli and salty food for breakfast, but so far they are adjusting well.

Lunch: This is served in a really nice French style with waiters and everything. Everyone has their own assigned napkin and we sit at nicely covered tables. First the waiters serve the appetizer, which is usually some fresh vegetables or something warm. Next the main course is served. This is often a meat or fish dish with rice, potatoes or vegetables, and is always nicely flavored and prepared. If you are still hungry the waiters show up with a tray of assorted cheeses from different regions of France to choose from. Finally it is time for dessert! Everyday there is a new dessert on the menu. This is a thrill for some of us!

Dinner: The main difference between lunch and dinner is that fresh fruit is served for dessert with dinner. Both lunch and dinner are served with white and red wine and water as well.

Due to the shifts, lunch is served at both 11:00 and 12:15. Dinner is at 19:00 and at 20:15. It is unusual for some of us to go eight hours without food, but we can find us some small snacks in the kitchen in between meals if we want to.

After the meals, good coffee is served in the bar, probably a French roast. It is dark and full of flavor.

That?s all for to today. Have a nice Sunday!

Your fellow teachers at sea

Hélder - Jean - Gertrud - Catalina - Angela - Carlo

PS! Remember you can follow the rout on the www.ipev.fr - position des navires Marion Dufresne. And unfortunately, we have had problems sending photos to many of you. We will look in to that problem.

Dia 8 (22Jun)

Coordenadas: 42˚38’ N 32˚16’ W

Olá a todos!!!

Como vos disse ontem o tratamento dos sedimentos recolhidos durante o dia de ontem e madrugada de hoje deram-nos bastante trabalho. No entanto, ao terminarmos o turno às oito da manhã, como é Domingo, tivemos direito a um pequeno-almoço especial que incluiu croissants recheados com chocolate. Estavam uma delícia…

Para além da Ciência, às vezes também é preciso lavar roupa.

Entretanto, durante a madrugada após se ter recolhido o tubo Calypso para o convés zarpámos rumo à região da falha Charlie-Gibbs onde, em 1967, o navio oceanográfico R/V Charcot conseguiu obter cerca de seis metros de sedimentos. Durante o cruzeiro MD168 AMOCINT pretende-se obter sedimentos mais profundos usando os equipamentos de carotagem Casq e eventualmente também o sistema Calypso (que vos descreverei amanhã detalhadamente).

O Sol brilhou durante toda a manhã. Um pouco antes do almoço tivemos a oportunidade de avistar novamente terra firme. Passámos relativamente perto das ilhas das Flores e do Corvo, Todavia, algum tempo depois, ao atravessarmos o paralelo 40 deixou de brilhar e a tarde foi um pouco cinzenta e chuvosa. Isso fez com que nos lembrássemos que nos esperam condições climatéricas bem mais adversas e todos receamos o frio com que certamente nos iremos deparar nas latitudes para onde nos deslocamos. O mar esteve também mais agitado do que durante o resto da semana.

Durante a equipa de professores a bordo aproveitou para escrever e actualizar as notícias que temos enviado a professores de escolas de vários países relativas ao cruzeiro e ao projecto AMOCINT. Aproveitei ainda para lavar a roupa suja.

Esperam-nos cerca de dois dias de “trânsito” até à Charlie-Gibbs.

Dia 6 (20Jun)

Coordenadas: 35˚43’ N 24˚ 21’ W

Olá a todos!!!

O mar esteve calmo durante todo o dia e continuámos “em trânsito” em direcção à região dos Açores. Choveu um pouco durante a manhã e fez-se sentir vento. Ainda assim, nem toda a gente se apercebeu disso, pois ontem à noite celebrámos o aniversário do George Oggian (um simpático técnico laboratorial de Bordéus) e houve uma grande e bela festa a bordo.

Ao ler os emails que recebemos de manhã fiquei super contente por saber que os Celtics, de Boston, venceram o sexto jogo da final da NBA contra os Lakers, de Los Angeles, tendo conseguido o seu 17.º título (e o respectivo anel) 22 anos depois da sua última conquista.

Palestra sobre sedimentação marinha

À tarde a equipa de professores, após ter assistido a mais uma palestra sobre sedimentação marinha e o estudo dos paleoclimas, aproveitou para avançar com a divulgação do projecto AMOCINT e do trabalho desenvolvido a bordo do R/V Marion Dufresne quer pelos cientistas, quer pelos restantes membros da tripulação.

Trabalhando na divulgação

Amanhã de manhã teremos muito trabalho, pois chegaremos ao local da primeira estação de recolha de sedimentos na zona dos Açores e serão recolhidos vários testemunhos de sedimentos.

Day 6 (20 Jun)

Position: 35°43N / 24°21W

You can follow the rout on www.ipev.fr – position des naires Marion Dufresne

Dear fellow Teachers,

Tonight we are still travelling towards the Azores. We had a rainy morning with wind about 50km an hour (ca 27 Nts). But now the beautiful sun is shining again. We have a place we call the “beach” in front of the ship. There we find especially the Scandinavians soaked in sunoil and sunrays! In their defense, they come from the rainiest city in Norway and therefore need to store vitamin-D for the wintertime. Since there is no work today, most people are busy writing emails and reports, or just resting.

Taking Cores

The sediment on the ocean floor represents layers of geological history. Therefore, if we can sample a vertical slice of this sediment, we will be able to obtain information about conditions during previous time periods. This information will allow us to make connections between past, present, and future climate and circulation patterns. This is extremely important to understand the current warming trend within the context of other interglacial, or warming periods.

Casq coring system

It takes a lot of work and sophisticated equipment to take a “slice,” or a core, of sediment. We use the Calypso coring system to acquire longer cores (maximum of about 60 meters). These longer cores are important to study more distant time periods. We are taking two other types of cores: Casq (or calypso squared) cores, and multi-cores. The Casq core is not as long as the Calypso core, but it provides undisturbed sediments. How much time is represented in a core depends on sedimentation rate and the length of the core. The multi-core is even shorter than the Casq core, however, it provides even greater detail about the surface layers of sediment. Also, the multi-corecovers a larger lateral area, and so gives us information about lateral variation of the sediment. We will discuss the equipment involved in more detail in a subsequent entry.

Calypso coring system

There are many factors that must be taken into account when choosing coring sites. First, we use echosounding to determine the depth, the topography of the sea floor, and the characteristics of the layers of sediment. The ship has electric engines because they are quiet, and will not interfere with the echosounding technology. Also this type of engine allows the ship to remain stable during the coring operation.

Echosounding profile

Even though some sampling sites are pre-determined, it takes hours to find the site and position the ship. If the ship is moving coring is impossible. The topography at the sites must be flat and at the apex of a dome-shaped peak (so the sample is not contaminated by slipping sediment). The area must have enough parallel sediment layers to be sampled, and the sediments must be of a certain type (the area cannot be too rocky).

Our first core off the coast off Morocco was about 40 meters long. It was a bit bent due to the trigger not functioning properly. We were, however, able to process the sample, and the information will be very useful in reconstructing conditions during past interglacial periods. Now that we have one Casq core, one multi-core, and three Calypso cores from our first two sites, we are ready to process the samples!

Processing a core

In a later email we will detail some of the work that goes into processing and storing these samples. Since this is an interdisciplinary endeavor we will be able to detail many applications of chemistry, physics, geology, oceanography, climatology and biology, which we hope you will share with your students.

Your sailor team Teachers at Sea!

Hélder – Angela – Catalina – Jean – Gertrud – Carlo