Week 6

Tomorrow is the kite flying contest. It’s not known exactly how many participants there will be. Many are working on their kites in secret so that no one will see their design.  Mine is made from bubble wrap and packing tape attached to bent wooden sticks with epoxy. It is in the shape of an upside down teardrop. The tail is four pieces of nylon strapping tape doubled over, with cut-outs of flying fish on it. If it ends up in the water it can be used as bait. The abundant mahi mahi fish that swim in these waters love flying fish. When I go out late at night I can see the fish attracted to the lights shining into the water. The flying fish are chased and, if caught, eaten by the mahi mahi. This is firsthand evidence of the food chain in action.

The kite flying contest was a success! I didn’t stop to count the number of participants but there were a lot of people on the heli-deck. The weather looked a little questionable first thing in the morning, but it cleared by 1300, the time set for the contest. My kite made it up and stayed up for quite a while. The wind was stronger than I had anticipated; some of the wind gusts were quite strong. I had thick nylon string, but I was afraid that either the kite would fall apart or the string would break; fortunately, neither happened.  The categories and winners for the contest were:  Highest Flying:  Nilo Amante, AB Seaman/Roustabout (Philippines) and Rudy Pena, AB Seaman/Roustabout (Philippines); Most Unusual:  the igneous petrology group consisting of  Takashi Sano, Igneous Petrologist (Japan); Carole Cordier, Igneous Petrologist (France); Sedelia Durand, Igneous Petrologist (US); and Jorg Geldmacher, Igneous Petrologist (Germany), made from the inside liner of a cereal box;  Nearly Flew:  Sara Holter, Undergraduate Trainee (US); and Most Colorful:  John Eastlund, IODP/TAMU Developer (US).

Emilio Herrero, Paleomagnetist (US) in front of the cryogenic magnetometer. *

Last night I worked with Emilio Herrero, Paleomagnetist (US), and Eugenio “Andres” Veloso Espinosa, Paleomagnetist (Japan), as they measured samples in the paleomagnetics lab. Paleomagnetists study the magnetic properties of sediment and rocks. One of the shipboard instruments used by the paleomagnetists is the automated pass-through cryogenic magnetometer. Super-cooled by liquid helium, the magnetometer measures the magnetic properties of rock samples. An alternating frequency demagnetizer attached to the magnetometer demagnetizes the samples in stages and the magnetometer measures the remaining magnetic field left in the rock after each demagnetization stage. The oriented samples are placed on a tray at one end of the instrument, and it moves them through the instrument automatically performing each demagnetization step. A readout of paleo declination and inclination (directions of the Earth’s magnetic field at time the rock cooled) and magnetic intensity of the rock are generated for each sample as a set of graphs.

Yongjun Gao, Inorganic Geochemist (US); Haroldo Lledo, Inorganic Geochemist (US); and Tetsuya Sakuyama, Inorganic Geochemist (Japan).

The chemistry group consists of Haroldo Lledo, Inorganic Geochemist (US); Yongjun Gao, Inorganic Geochemist (US); and Tetsuya Sakuyama, Inorganic Geochemist (Japan). Elemental analyses are done using the Inductively Coupled Plasma – Atomic Emission Spectrometer (ICP-AES).   

Before a sample can be placed in the ICP-AES, it must be cleaned and ground into a fine powder. A measured sample is brought up to 1025°C to determine the weight loss of volatiles that have been ignited. The powder is then put into a solution and pumped into the ICP-AES. A very small amount is sprayed into a plasma flame. The spectrum emitted by the superheated elements is read and converted to a chart that looks like those shown on a popular forensic television series.  So now I know how it’s really done. The peaks on the chart are compared to a standard, and the element is identified and its concentration determined.

Mineral identification is done using the X-Ray Diffractometer (XRD). As with the ICP-AES, the samples put into the XRD originate in powdered form. The difference is that for the XRD the samples have not gone through the heating process. The powder is put onto small slides that are bombarded with X-rays when put in the instrument; the pattern the X-rays give off when they hit minerals in a sample is recorded.  The pattern is characteristic for different minerals and is used to determine the mineral phases present in a given sample.

For both the ICP-AES and the XRD, the preparation of the sample is crucial. In a shore-based lab the processing is hard enough, but on a ship it is another story.  My hat is off to the lab technicians who consistently prepare and process samples in a lab that is in constant motion.