Limits...
Ocean bottom seismometer: design and test of a measurement system for marine seismology.

Mànuel A, Roset X, Del Rio J, Toma DM, Carreras N, Panahi SS, Garcia-Benadí A, Owen T, Cadena J - Sensors (Basel) (2012)

Bottom Line: Ocean Bottom Seismometers (OBS) have received growing attention from the geoscience community during the last forty years.In a seismic survey, a series of OBSs are placed on the seabed of the area under study, where they record either natural seismic activity or acoustic signals generated by compressed air-guns on the ocean surface.The resulting data sets are subsequently used to model both the earthquake locations and the crustal structure.

View Article: PubMed Central - PubMed

Affiliation: SARTI Group, Electronics Department, Universitat Politècnica de Catalunya, UPC.Vilanova i la Geltrú 08800, Spain. antoni.manuel@upc.edu

ABSTRACT
The Ocean Bottom Seismometer (OBS) is a key instrument for the geophysical study of sea sub-bottom layers. At present, more reliable autonomous instruments capable of recording underwater for long periods of time and therefore handling large data storage are needed. This paper presents a new Ocean Bottom Seismometer designed to be used in long duration seismic surveys. Power consumption and noise level of the acquisition system are the key points to optimize the autonomy and the data quality. To achieve our goals, a new low power data logger with high resolution and Signal-to-Noise Ratio (SNR) based on Compact Flash memory card is designed to enable continuous data acquisition. The equipment represents the achievement of joint work from different scientific and technological disciplines as electronics, mechanics, acoustics, communications, information technology, marine geophysics, etc. This easy to handle and sophisticated equipment allows the recording of useful controlled source and passive seismic data, as well as other time varying data, with multiple applications in marine environment research. We have been working on a series of prototypes for ten years to improve many of the aspects that make the equipment easy to handle and useful to work in deep-water areas. Ocean Bottom Seismometers (OBS) have received growing attention from the geoscience community during the last forty years. OBS sensors recording motion of the ocean floor hold key information in order to study offshore seismicity and to explore the Earth's crust. In a seismic survey, a series of OBSs are placed on the seabed of the area under study, where they record either natural seismic activity or acoustic signals generated by compressed air-guns on the ocean surface. The resulting data sets are subsequently used to model both the earthquake locations and the crustal structure.

No MeSH data available.


Related in: MedlinePlus

Primary and secondary waves.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3376630&req=5

f1-sensors-12-03693: Primary and secondary waves.

Mentions: Both earthquake and controlled seismic source use the propagation of both P (primary) and S (secondary) waves through the earth’s crust to obtain information relating to the propagation path. The S-wave moves as a shear or transverse wave, so motion is perpendicular to the direction of wave propagation, and P-wave has the highest velocity and is therefore the first to be recorded, and is formed from alternating compressions and rarefactions [3,4]. Figure 1 depicts how these waves propagate. P waves travel through sea water and the earth’s crust with relatively slow loss of energy but S waves (shear waves) do not propagate at all through fluids. The advantage of OBSs for recording on the seabed rather than using towed arrays to record in the water column is that OBSs can record seabed shear waves directly as vectors using three component geophones, thus providing much useful additional information to inform the interpretation process.


Ocean bottom seismometer: design and test of a measurement system for marine seismology.

Mànuel A, Roset X, Del Rio J, Toma DM, Carreras N, Panahi SS, Garcia-Benadí A, Owen T, Cadena J - Sensors (Basel) (2012)

Primary and secondary waves.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3376630&req=5

f1-sensors-12-03693: Primary and secondary waves.
Mentions: Both earthquake and controlled seismic source use the propagation of both P (primary) and S (secondary) waves through the earth’s crust to obtain information relating to the propagation path. The S-wave moves as a shear or transverse wave, so motion is perpendicular to the direction of wave propagation, and P-wave has the highest velocity and is therefore the first to be recorded, and is formed from alternating compressions and rarefactions [3,4]. Figure 1 depicts how these waves propagate. P waves travel through sea water and the earth’s crust with relatively slow loss of energy but S waves (shear waves) do not propagate at all through fluids. The advantage of OBSs for recording on the seabed rather than using towed arrays to record in the water column is that OBSs can record seabed shear waves directly as vectors using three component geophones, thus providing much useful additional information to inform the interpretation process.

Bottom Line: Ocean Bottom Seismometers (OBS) have received growing attention from the geoscience community during the last forty years.In a seismic survey, a series of OBSs are placed on the seabed of the area under study, where they record either natural seismic activity or acoustic signals generated by compressed air-guns on the ocean surface.The resulting data sets are subsequently used to model both the earthquake locations and the crustal structure.

View Article: PubMed Central - PubMed

Affiliation: SARTI Group, Electronics Department, Universitat Politècnica de Catalunya, UPC.Vilanova i la Geltrú 08800, Spain. antoni.manuel@upc.edu

ABSTRACT
The Ocean Bottom Seismometer (OBS) is a key instrument for the geophysical study of sea sub-bottom layers. At present, more reliable autonomous instruments capable of recording underwater for long periods of time and therefore handling large data storage are needed. This paper presents a new Ocean Bottom Seismometer designed to be used in long duration seismic surveys. Power consumption and noise level of the acquisition system are the key points to optimize the autonomy and the data quality. To achieve our goals, a new low power data logger with high resolution and Signal-to-Noise Ratio (SNR) based on Compact Flash memory card is designed to enable continuous data acquisition. The equipment represents the achievement of joint work from different scientific and technological disciplines as electronics, mechanics, acoustics, communications, information technology, marine geophysics, etc. This easy to handle and sophisticated equipment allows the recording of useful controlled source and passive seismic data, as well as other time varying data, with multiple applications in marine environment research. We have been working on a series of prototypes for ten years to improve many of the aspects that make the equipment easy to handle and useful to work in deep-water areas. Ocean Bottom Seismometers (OBS) have received growing attention from the geoscience community during the last forty years. OBS sensors recording motion of the ocean floor hold key information in order to study offshore seismicity and to explore the Earth's crust. In a seismic survey, a series of OBSs are placed on the seabed of the area under study, where they record either natural seismic activity or acoustic signals generated by compressed air-guns on the ocean surface. The resulting data sets are subsequently used to model both the earthquake locations and the crustal structure.

No MeSH data available.


Related in: MedlinePlus