31 January, 2004

Work ended at midnight last night due to an emergency return to Port Moresby. One of the crew learned of a death in his family and needed to fly home. The ship was about 15 hours from Port Moresby, so we steamed all night. The science team used this time to catch up on work and rest.

J.P. Walsh, an Assistant Professor from East Carolina University, led today´s lecture. He gave us an introduction to the tools and techniques for sea floor mapping. He described how these methods are part of the nested approach that the PNG S2S team of scientists is of using to understand sediment dispersal in the Fly River both today and in the past. During the cruise we are working with a variety of sea-floor-mapping equipment that are both mounted to the hull of the ship and towed in the water column. Hull-mounted equipment includes the multibeam, Sea Beam 2000, used for mapping the depth of the seafloor (also know as bathymetry) and the Knudsen 3.5 and 12.5 kHz (kilohertz) echosounders, the latter of which can reveal sedimentary strata tens of meters below the seabed, under ideal conditions. Towed instruments include the side scan sonar (SSS) and Chirp. The SSS measures the backscatter of sound from the sea floor, and the Chirp uses sound to examine the sedimentary strata below the sea floor, like the 3.5 kHz system. However, it is capable of superior resolution and penetration (depth into the sea floor). J.P. discussed how different types of cores are being used, such as the box core, multi core, kasten core, piston core and jumbo piston core, to bring back undisturbed layers of sediment samples from the sea floor to compare with the observations from sound-generating instruments. Please visit the sampling equipment page of this web site to see examples and learn more about all of these tools.

About three in the afternoon we arrived near Port Moresby. We passed several small motorboats with people fishing and waving hello. The pilot ship met us outside the harbor. Rather than steering the ship into port, they picked up the crewmember and brought him to Port Moresby. Many people gathered on deck to wave goodbye and wish him well. The day looked stormy over Port Moresby and the surrounding area, but with the sunlight shining down, it made for beautiful views. We quickly turned around and headed back out into the Gulf of Papua. Arrival at the next research site was set for 0600 on the 1st of February.

I spent the rest of the afternoon reading and talking with friends on the deck. Following dinner, a group of us returned outside to sit on the fantail and watch the sunset. Soon rain set in so we quickly moved our chairs under a covered work area. After dark, we went to the galley to watch some of the crew and researchers play poker. About 10 PM while getting ready for bed, I heard the sound of a hard downpour interrupted by long blasts of the ship´s horn, which is quite loud! This served as a signal to any surrounding boats of our location as visibility was reduced during the dark and rainy night (much like a fog).

Weather
(Today's weather and location at 0900)

Air Temperature: 29°C
Water Temperature: 30°C
Salinity: 34.25 PSU
Barometric Pressure: 1006 cmbar
Precipitation: 14.3mm (last 24 hours)
Relative Hummidity: 76%

Location
Longitude: 145° 54´ E
Latitude: 9° 21´ S

Menu
Breakfast: Bacon, ham, eggs, potatoes, fresh fruit
Lunch: Pizza
Dinner: Chicken and rice, Spaghetti and meat sauce
Dessert: apple pie and ice cream