April 15, 2009

PUNTA ARENAS, CHILE– Late last night we arrived at Punta Arenas, Chile. This marks the end of our Iceberg 3 cruise. We have finished analyzing the samples, re-calibrating instruments and we are now ready to start packing. We leave in 4 days; in the interim we will do an inventory of supplies, clean instruments, enter data and pack to be ready to leave on the 19th. Some of us are going back home, others will travel for a few days in the South of Chile or as far north as Ecuador.

Earlier today we met to share our findings during the cruise and plan data analysis and publication of results. Each of us gave a 5 minute (sometimes extending to 15 minute) presentation. It was impressive to see how much we had learned. We have now data that shows the changes in physics, chemistry and biology in the wake of an iceberg, we have improved the comparison of areas affected and not affected by the presence of an iceberg and we can tell how different the iceberg imprint in surface waters is at different times of the year in the North West Weddell Sea (summer, fall and winter). We have accomplished our goal of testing the release of iron to surface waters and the response of phytoplankton and bacteria. This was done not only by measurements in the ocean at different distances from icebergs but also through experiments with iron additions.

These photos show some of the wide variety of icebergs we saw in the northwest Weddell Sea. Notice the blue ice in this iceberg.

The black stripes in this “dirty” iceberg are caused by sediments trapped in the ice.

It was decided we will meet next month in Monterey, California. At that time we expect to have a more in-depth analysis of data that will allow us to synthesize findings in a more comprehensive way. Science carried out in interdisciplinary groups is based not only on results from the individual researchers but also on how well we can combine our findings to describe the iceberg system.

Until the next one!