Olá a todos!!!
Participem comigo nesta aventura, acompanhando o trabalho desenvolvido por uma equipa internacional de cientistas, a bordo do R/V Marion Dufresne, durante o cruzeiro oceanográfico MD168 - AMOCINT (IMAGES XVII) que decorrerá, no Atlântico Norte, entre 15 de Junho e 10 de Julho de 2008.

Estou a contar com os vossos comentários e questões!

Obrigado a todos pelo vosso apoio e colaboração...

Hélder Pereira
"Teachers at Sea"
Educational Program
Escola Secundária de Loulé

sábado, 28 de junho de 2008

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

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