27 November, 1995

November 27, 1995

Location: 64 55' South Latitude x 127 13' West Longitude -- In Transit


At 2:00 PM local we moved our clocks back to 1:00 PM. Another day, another time zone. Gaining an hour has almost become a regular part of the day. It is often said that there are never enough hours in a day. Even at twenty five hours a day there still does not seem to be enough.

We are on a course of 274 degrees, slightly north of west, following a great circle course. We have been averaging about 11 knots. The Captain fired up all four engines today to make some time in the calm seas. We cruised for about ten hours at 14 knots.

As we inch ever further north, the sun has begun to follow a more recognizable cycle. At 1:00 AM the sun had descended just ever so slightly below the horizon. For less than thirty minutes we were teased with a nearly sunless dusk. It was the closest we had been to experiencing night in weeks. It was peculiar to look out the portholes on watch and to feel as though the ship was veiled in a cloak of feeble darkness. The darkness was fleeting, just a hint of what the future held. I felt closer to home in that short half hour of dusk. Closer to normalcy. Closer to home.

The clouds could not seem to muster the endurance to dominate the skies today. Early in the morning, slight breaks in the thick gray blanket that has held the blue sky hostage for days were glimpsed. A change was underway. A change to the most glorious evening since we left the Bransfield Strait. At 11:00 PM the sun was an enormous yellow beacon on the western horizon. A silver crescent of moon hung delicately to the east in the pale blue evening sky. The sea was awash in light, reflecting beams in all directions from its gentle swells.

Taken by surprise again. Mother nature prepared another glorious feast of light and color just when we least expected, and when we needed it the most. Many of us just lounged out on the deck, devouring the banquet of sunshine that had been prepared for us. The sea extended endlessly to the horizon. Because of the clear sky it seemed that we could see farther than our vision was capable. The horizon was merely a reference rather than a point of termination. It seems that on a clear day at sea, you can almost see forever, and forever is breathtaking. The sea looked a vivid blue. The waves, a puzzle of motion and form, charm the watcher to seek patterns in the undulating surface. You can see pictures made in the swell and hear the waves speak poems as you become enchanted by the call of the sea.

It is easy to forget the power of the ocean when you are part of the calming spectacle on a sun filled day at sea. There is so much beauty that it defies you to see anything else. By midnight, the sun was low on the horizon, full and red, master of the day. I was not sure if we would see dusk, or merely rush into dawn. I really didn't want to see the day end.

We started collecting geomagnetic data today. When geophysicists study geomagnetism they are interested variations in the direction and strength of the magnetic field in rock layers within the crust. We are able to tell the direction north and south using a compass. The compass is a small magnet which aligns itself in the magnetic field of the earth. We can think of the earth as having a huge magnet passing though its center. The south pole of the magnet is at the north pole of the earth, and the north pole of this magnet is at the south pole in Antarctica . When our compass points to the direction of north it is really being attracted by the magnetically opposite pole in the earths center.

The direction of the magnetic poles is not constant. Sometimes the poles completely flip directions, sometimes they just change direction a few degrees. These changes happen over millions of years and are recorded in the layers of rock that make up the earth's crust.

When new crust is formed from molten rock from within the earth, the iron atoms in these new rocks align with the magnetic poles of the earth. This creates a mini magnet in the crust. Usually these magnetic areas are very large and cover thousands of miles. The direction of the poles and the strength of these magnetic zones within the crust are dependent upon the direction and the strength of the earth's magnetic field when the molten rock cooled.

When there are regions of molten rock close to the surface, or if regions within the large regions of crust are affected by volcanic activity or plate motion, small variations in the magnetic field of these areas can occur. These variations in strength and direction of the magnetic fields are called magnetic anomalies. Geophysicists are interested in locating these anomalies because they are indications of changes in the crust due to the release of stress from the movement of tectonic plates. This is a very simplified explanation of the theory, but I think it conveys that the earth's crust is a complex system, and one important characteristic of that system is geomagnetism.

This earth's crustal system is constantly changing, but at a rate that seems unimaginably slow. The time scale of the earth is in thousands and millions of years. Change happens slowly. The evidence of these slow changes are mountains, valleys, volcanoes, faults, and subtle variations like magnetic anomalies.

The magnetometer is used to detect these magnetic anomalies. This device is towed behind the ship and detects variations in the magnetic field. It is another tool in the geophysicists chest of gadgets for learning about the earth's crust.

We have found some very interesting formations from the sea beam data. These features have been quite unexpected. The area of the sea floor over which we are traveling is very flat with very little variation. The depth is nearly 5000 meters. Some of these features are over 500 meters high. They are like single billboards along a long desolate desert highway. They are sign posts marking change and stress in the earth's crust for the scientists on board. They are newly found pieces to a scientific puzzle which still has many holes.

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