Ground motion measurement is a vital source of data, providing valuable information on subsurface lithology and structure both on land and at sea.
While onshore investigations are straightforward, offshore they can often pose a range of difficulties such as time limitations due to high power consumption, noise interference from currents, and poor seabed coupling. And while broadband seismometers in OBSs are now relatively common, they can be too large and expensive for use on many operations (e.g. active seismic projects where higher frequency signals are recorded).
To address this, KUMO has developed a standalone subsea Geophone to optimise the accuracy of data collection. It delivers an outstanding signal-to-noise ratio with a special pressure housing for 3C-Geophones that resides externally from the main instrument and is connected by just a flexible cable. This way, the Geophone is decoupled from any possible unwanted noise produced by the main instrument itself (e.g. the OBS) that may lead to inaccuracies within the data.
Our three-part Geophone features a compact, grooved titanium design tailored to ensure the best seafloor coupling while simultaneously providing excellent protection from corrosion. The Geophone is best used with a range of KUMOs OBS instruments, all of which have been designed and tested together. However, the device is equally compatible with a wide range of third-party instruments.
|Frequency range||4.5 Hz – operates at +/-30 deg 10 Hz – Omnidirectional 14 Hz – Omnidirectional 30 Hz – Omnidirectional|
|Damping (open circuit)||0.56 % (±5%)|
|Moving mass||0.0111 kg|
|Sensitivity (open circuit)||28.8 V/m/s (±5%)|
|Sensors||3 orthogonal geophones|
|Operational depth||6000 m|
|Dimensions||Diameter – 160 mm, Height – 57 mm|
|Weight||2.6 kg (air), 1.6 kg (water)|