This is the first "weekly" report since receiving the Chief Scientist Letter from Dawn Scarbourg on 1 May 2001. Please note that daily reports
have been prepared and sent out to a variety of individuals since we left Punta Arenas, Chile, including the Web Master of the Southern Ocean
GLOBEC Web Site. It is my understanding that these daily reports are being posted there and are available to anyone wishing to read them.
The overall goals of the SO GLOBEC Program are :
shelf circulation processes and their effect on sea ice formation and Antarctic
krill (Euphausia superba) distribution.
·To examine the factors that govern krill survivorship and availability to higher trophic levels, including seals, penguins, and whales.
To this end, a series of two ship cruises were planned during which
one ship would carry out the broad-scale mapping of the hydrography and
of the study site and the other ship would carry out site specific processes studies to link the physical features of the environment to the dynamics of
the target species and their predators and prey. The work on the R/V Palmer is dedicated to the survey and mapping of the region.
We left Punta Arenas on the Morning of 24 April 2001. During the transit
with the pilot through the Magellan Straits, we conducted noise tests with
acoustic system on the towed body known as BIOMAPER-II, in the presence of an expert from Hydroacoustical Technology Inc. We also tested the winch,
slack tensioner, and over-boarding handling system for BIOMAPER-II, while the two individuals from WHOI who installed the equipment were still on board
the R/V Palmer, and some adjustments were made before they disembarked with the pilot at the eastern end of the straits.
The steam across the Drake, which began with benign seas and then became
quite rough, was uneventful. The seabird ecologists and the marine mammal
ecologists were active in surveying their respective populations during the daylight hours. When we reached the 200 mile limit of Argentina, the Seabeam
system was turned on, a Sonabuoy was deployed to listen for whale calls, and an XBT survey of the passage was begun. Additional Sonabuoy work was
carried out during the transit across the Western Peninsula Shelf to Palmer Station to rendezvous with the R/V L.M. Gould at Palmer
Station in order to transfer gear needed by the Gould for their process
work and some other material. The rendezvous took place on the morning
of 28 April 2001
and later in the day, both ships set off towards the first survey station to the southwest of the Palmer Station and the first process work site nearby.
Work commenced at Consecutive Station #1 (grid location 499.251 -65.8138°S;
-70.3880°W) early on the morning of 29 April 2001. The grid of stations
extends from the northern tip of Adelaide Island to southern part of Alexander
Island and covers the continental shelf to just beyond the shelf break
and Marguerite Bay.
As of 4 May 2001, we have carried out the work programmed for stations 1 to 22, except that Station 21, an offshore deep water was dropped. The work included thirty-two CTD profiles, five 1-m2 MOCNESS tows, approximately 20 Sonabuoy deployments and eight BIOMAPER II deployments. BIOMAPER-II is towyo'd in a sawtooth pattern between the surface and 250 m during transits between stations. The bird and mammal survey groups have made a number of sightings along the four transect lines now completed. In addition, Seabeam bathymetry data are being collected around the clock, as are the ADCP data, surface temperature, salinity, and fluorescence data, and meteorological data.
We are making very good progress in spite of less than optimal weather
conditions and the support we are receiving from the Raytheon technical
support group and
the ship's officers and crew has been excellent. To read the daily reports, which provide more detail, go to the U.S. GLOBEC Web site (www.usglobec.org) and click on the SO GLOBEC icon to get to the SO GLOBEC Web site.
Peter Wiebe, Chief Scientist