Gravity and magnetic observations
Modern techniques and equipment make it possible to carry out large-scale high-precision gravity and magnetometer surveys and regional studies along with seismic acquisition. Regular grid magnetometer surveys are ±0.5-2 nT accurate and ±3-5 nT accurate together with seismic acquisition. Added to acquisition, gravity surveys are conducted at sea state 4 with an accuracy of ±0.3-0.4 mGal and that of ±0.1-0.2 mGal during detailed work.
Geophysical Equipment
Chekan-AM gravimeters, Chekan-AM (Shelf-E model)
Manufacturer: Concern CSRI Elektropribor, JSC, Russia
- Range: at least 10 Gal
- Absolute error limit: ±0.3-0.8 mGal
- Sensitivity (scale division value): 0.01 mGal
- Time constant: 35 to 100 sec
- Drift rate: at least 3 mGal/day
SeaSPY2 magnetometers (Marine Magnetics, Canada)
- Absolute accuracy: 0.1 nT
- Sensor sensitivity: 0.01 nT
- Counter sensitivity: 0.001 nT
- Range: 18,000 nT to 120,000 nT
- Gradient tolerance: over 10,000 nT/m
Sentinel base station magnetometers (Marine Magnetics, Canada)
- Absolute accuracy: 0.2 nT
- Sensor sensitivity: 0.01 nT
- Range: 18,000 nT to 120,000 nT
- Gradient tolerance: over 10,000 nT/m
- Storage capacity: one million readings
- Sampling rates: 1/minute to 1Hz
