Seismic
What are seismic surveys?
Seismic surveys have been carried out in Germany and other parts of the world since the early 1920s. The method was developed by the German geologist Ludger Mintrop. Mintrop invented a portable seismograph with which sound waves coming from the earth could be heard and recorded. Electronics, recording technology and much else has changed significantly since that time.
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Seismic measurements are echo sounding measurements of the earth. In this process, a sound wave is sent into the earth, which is reflected by the different layers of the earth and thus provides an echo image of the subsurface.The principle is similar to the echo sounder used on ships to measure the depth of water, or ultrasound, which is used in medicine.
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The measuring instruments for generating sound and receiving the echoes differ depending on the application. On ships and in medicine, sound or ultrasound waves can be emitted and received with the same instruments. The data can be used immediately. Measurements into the depths of the earth, on the other hand, are somewhat more complicated, especially the data processing with high-performance computers.
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The sound waves in seismic measurements are generated by special vibro-vehicles (shaking trucks). The sound waves generated are very low frequency (in the range of 5 to 150 Hz) and can only be perceived by people in the immediate vicinity of the vibro-vehicles as slight vibrations in the ground. Echoes are generated in the ground where the geology of the rock changes, similar to the change between air and rock on a cliff face.
Recording devices on the Earth's surface record the echoes. These are digitally processed with high-performance computers to create a sound image of the Earth. The recording devices consist of small, very sensitive microphones, so-called geophones, which are attached to the ground and connected via cable and/or radio to an electronic recording system located in a measuring vehicle.
The seismic recordings are usually arranged on pre-measured lines or flat on the surface in a grid so that the geologists obtain a 3D sound image of the earth. After the measurement, the equipment and geophones are removed and any traces (e.g. driving tracks on dirt roads) are removed. As with other activities, Jasper Resources will carry out all work processes with the utmost consideration for the environment and people in order to minimise their impact.
What is seismic data used for?
Seismic measurements are used to create a sound image of the earth, just as ultrasound surveys are used to create a sound image of humans. The image below shows a sound image along a seismic line of the subsurface under Zehdenick. Geologists can use the sound image of the earth to create maps to assess, for example, where natural gas is stored or how big a natural gas deposit is.
