What is an Ocean Bottom Seismometer?
Seismometers acquire sound information through the earth. Acoustic waves (sound) travel in the form of very small motions which advance through the earth with time. The seismometer (or geophone) is a detector that is placed in direct contact with the earth to convert very small motions of the earth into electrical signals, which are recorded digitally. Each seismometer consists of a mass, which contains an electrical coil, that is suspended by a spring between the poles of a magnet. When the earth moves, the magnet and spring support move with the earth. The mass tends to remain stationary, so its motion will lag behind that of the magnet. This relative motion produces a voltage that is proportional to the velocity of this motion. The sound waves are generated by either earthquakes at depth or by man-made devices near the surface of the earth. Motions of the earth, combined with precise timing and location information for the sound source and the receiver (the seismometer), can provide
