Report of Activities on the RVIB N.B. Palmer Cruise 02-02

16-17 May 2002

On 16 May, the N.B. Palmer arrived in Arthur Harbor on Anvers Island where the Palmer Station is located just before noon after a 16 hour steam from Crystal Sound. Since the dock was too small and the water too shallow to tie up at the Station, the ship held station in the harbor. Joe Pettit, the Palmer Station Director, came by Zodiac out to the ship about 1300 to issue a welcome and to brief us on the ins and outs of the Station. During the stay, several Zodiac trips were arranged to enable the scientists on board to visit small islands near the station on which there were seals and penguins that could be viewed up close (Torgersen and Humble Islands) and the wreck of an Argentine cruise ship that went down in late 1980's next to DeLaca and Janus Islands. It did so when upon leaving Arthur Harbor, it took a “shortcut” through a channel that was poorly charted and too shoal. On Torgersen Island, there were a number of fur and elephant seals, one Weddell seal, and about 16 penguins, and Humble Island had a number of elephant seals. A more regular shuttle service was set up to enable N.B. Palmer personnel to visit the station and become familiar with the activities there. In addition, it afforded the opportunity to do a short hike by climbing a small glacier that has its base a few hundred meters from Palmer Station. In the early evening, the N.B. Palmer hosted many of the residents of Palmer Station at a barbeque dinner and then later in the evening, many on the ship went to the Station to socialize.

The weather during the day was not wonderful; it was cloudy with on and off light snow or drizzle. Winds were around 20 kts out of the southwest, but the temperature was around -0.7ºC, the warmest it had been in quite a few days. The barometric pressure continued to drop from 1000.6 mlb in the morning to 995.9 mlb around midnight.

The N.B. Palmer left Palmer Station in the early morning hours of 17 May on a course that took us back to Punta Arenas, Chile via the inland passage. This route went first through the Bismark Strait along the southern side of Anvers Island and then along the Gerlache strait. To the northwest of this strait were Brabant and Liege Islands. To the east was the Danco Coast, the Arctowski Pennisula, and the Forbidden Plateau. All were snow and ice covered with ice cliffs at the waters edge. Sea ice and ice bergs occurred sporadically. The last point of land as we steamed through the Boyd Strait was Intercurrence Island at the end of the Palmer Achipelago. Although somewhat longer than the more direct route from Arthur Harbor out across the continental shelf, it was selected because marine mammal observation opportunities were enhanced and it is a beautiful passage. Furthermore, there was a great deal of work to be done on the deck and the passage afforded the protected waters needed to complete the work before running into the usual high wind and seas of the Drake Passage. One of the major tasks was to end-for-end the electro-optical cable used to tow BIOMAPER-II. The towing end of the cable had experienced a great deal of wear during the first three Southern Ocean GLOBEC broad-scale cruises and strands of the outer armor were beginning to break. Reversing the wire, put unused wire on the front line and the worn wire where it would not experience additional wear. The end-for-ending was done by laying the more than 600 m of cable in a figure eight on the deck and then winding the cable back on the winch drum in reverse. This sounds simple, but in fact it was a hard job that took most of the day and was done with great care by MTs Jenny White and Steve Tarrent, and BIOMAPER-II group members Phil Taisey, Gaelin Rosenwaks, Amy Kukulya and Andy Girard.

As anticipated, the Gerlache strait afforded Deb Glascow a great opportunity to observe several groups of whales, as reported below, in spite of the weather. In the morning, there was a light snow and low thick clouds, but low winds (< 10 kts). Visibility for a while was quite poor, but during the day it improved and there was even a bit of sunlight for short time. But the barometer continued to drop from 987.6 mlb around 0900 to 980.4 mlb around 2330 and the winds picked up to the low 20 kts by close of day. The air temperature varied between -2.3 to -0.4ºC.

At 1300 on 18 May, we are now well out into the Drake Passage. The seas are rough with winds in the 30 to 35 kt range. The barometer at 985 mlb is now rising. A sea surface temperature of -1.67ºC indicates that we are still in polar waters and that we have yet to cross the polar front. The CTD group has been dropping XCTDs, and XBTs at 10 nm intervals since reaching the 2000 m contour after leaving Boyd Strait early this morning. Seabeam bathymetry, ADCP, and along track meteorological and sea surface water properties continue to be measured. Most of this data collection will cease when we reach the 200 nm limit of Argentina late tonight or early tomorrow. From there, the Palmer will steam to the Estrecho del la Maire on the southern end of Argentina and then up along the eastern Argentine coast to the entrance to the Magellan straits. After picking up a pilot, the final leg of this cruise will be along the Magellan straits to Punta, Arenas, Chile, which we are scheduled to reach on the morning of 21 May.

This cruise has been very successful, having sampled at all of the survey grid stations and at a number of ancillary locations as well, in spite of encountering pack ice and icebergs about halfway along the survey grid that proved quite challenging. Some work that had to be dropped because of bad weather or equipment problems was later picked up and some special projects that could only be done after the grid was completed, such as the penguin diet sampling, were successfully accomplished. The success of this cruise owes much to the incredible competence, skill, and great attitude of the Raytheon technical support group. The officers and crew of the N.B. Palmer also provided superb assistance.

This will be last of the individual reports of the scientific activities aboard the N.B. Palmer on this the third in a series of four Southern Ocean GLOBEC cruises. Members of the scientific party are hard at work preparing their sections of the cruise report, which we plan to have completed by the time the ship reaches Punta Arenas.

Marine Mammal report (Debra Glasgow)

Thursday, 16 May dawned with fog, snow, and very poor visibility of <300 meters as the Palmer passed through an area of many growlers on its way from Crystal Sound to Palmer Station. Captain Joe Borkowski saw 2 humpbacks surface 50 meters off the port bow at approximately 0924. I was on the bridge 5 minutes later, but did not see them as the fog and snow limited visibility. No marine mammal survey was conducted today due to the inclement weather and arrival at Palmer Station at noon.

On 17 May, the marine mammal survey began at 0910 as the Palmer started the transit through Gerlache Strait in fog and snow. Visibility was poor at <1 nautical mile, but was variable, clearing late in the morning. It was a balmy -2.2ºC and a mere 4.5 knots of wind (increasing in the afternoon), with variable ice conditions with icebergs, bits, and growlers near the beginning of the Strait. Fur seals were seen on floes and in the water and a few elephant seals were also passed, mostly near the beginning of the Strait. Several groups of porpoising penguins were passed periodically.

At 1035, we encountered the first of 2 sightings of minke whales for the day and from then on whales were seen regularly. There were 7 sightings for the day, 14 whales in all. Two minke, 9 humpbacks and 3 like-humpbacks. The ship was made available today to deviate from our course to approach whales for I.D. photography purposes. Successful identification photographs were taken of 3 of the humpback groups.

One pod of 3 humpbacks first sighted at 1251, stayed with the ship for over half an hour as we stopped for I.D. photos, swimming to the ship, and surfacing right beside us repeatedly. Good I.D. photos were taken of this group and two of the whales had very distinctive dorsal fins and white patches on their flanks, fluke shots were successfully taken of at least 2 of the whales. The third whale was smaller and lighter in color. The two larger whales were surfacing side by side, often touching each other. These whales actually followed us briefly when we began moving on. The survey ended in poor light at 1539 as Palmer left the Gerlache Strait. There have been 54 cetacean sightings to date of 112 animals.

Cheers, Peter