Marine seismic data registration

BGR disposes of own measuring systems for the execution of marine seismic explorations.

Streamer Source: BGR

The digital streamer system used by BGR is a SEAL 408XL System from Sercel. It has an active length of 4000 m and is composed of 27 sections à 150 m. Each section contains 192 hydrophones composed to 12 traces ( or channels). This means that 16 hydrophones form one channel. All together accumulates (27 * 12) 324 channels for data acqusition.

• The streamer is controlled and depth-supervised by a controller System 3 from DigiCOURSE.
• The seismic energy is generated by a 50,8 liter G-gun airgun array, triggered by a GCS90 controller from Sercel/Syntron.

Concerning the seismic reflection data acquisition, the seismic waves reflected in the underground at geological boundaries are received via a hydrophone chain and converted into electrical signals. After digitalisation the measured data is stored onto digital tapes. The run time and amplitude of the reflection signals will provide later on information about depth and character of the boundary layer.
The hydrophones are linear-arranged in a 4000 m long streamer which is hauled behind the ship in about 8 m depth.

Standard measurement configuration for reflexion seismic data acquisition. Behind the research vessel, an airgun array is dragged, serving as a seismic source. With the help of hydrophones in the dragged measuring cable (streamer) the reflected waves are recorded. Source: BGR

The seismic data recorded in the scope of marine geophysical measuring trips are worked up and processed in the BGR. Recording seismic refraction data requires in comparison to seismic reflection data registration larger distances between seismic source and receivers.