Multi Channel Seismic (MCS) System

Modern marine geoscience requires accurate and detailed subsurface information for the mapping of geologic structures and sedimentary sequences beneath the continental margin. In order to acquire this information NIWA purchased a Multi Channel Seismic system (MCS) in December 1996, consisting of a 24 channel streamer, seismic source and acquisition hardware.

Modern marine geoscience requires accurate and detailed subsurface information for the mapping of geologic structures and sedimentary sequences beneath the continental margin.

In order to acquire this information NIWA purchased a Multi Channel Seismic system (MCS) in December 1996, consisting of a 24 channel streamer, seismic source and acquisition hardware.

Since then the MCS system has evolved to meet the tight specifications that NIWA science and industry have demanded. Improvements include provision for real-time streamer depth control, better data quality control, greater data acquisition capability (increased to 48 channels), extended streamer length and improved logging facilities. With this substantial investment in hardware and software, NIWA now has the potential to acquire shallow penetration seismic data of excellent quality.

The MCS system has been successfully deployed in numerous scientific voyages and commercial contracts.

Specifications

Array

Manufacturer	Geometrics Inc.
Type	Geoeel 42mm Digital Streamer
Specifications	48 channel 12.5m group spacing 16 hydrophones (Benthos Geopoint)/ group Group Sensitivity 20v / bar 30m deck cable 200m lead in 2 x 25m elastic section 7 x 100m active sections
Total Length	825m
A/D Converters	5 – 8000hz bandwidth 24 bit A/D 120db dynamic range 0.0625 – 4ms sample rate
QC Checks	Hydrophone Capacitance and leakage, Pulse, Oscillator, timing and DC Offset

Recorder

Manufacturer	Geometrics Inc.
Type	CNT-1
Specifications	Pentium IV Windows XP Operating system 2 x 20 Gbyte external DLT drive
QC Displays	Log, Shot, Spectra, Noise, Gather, Trigger, Tape.
Output	SCSI upto 4 Tape drives Real time gather (selected streamer channel)
Data Cycle time	< 1 second for 5 second record
Data Format	SEG2, SEG Y, SEG D

Energy Source

Manufacturer	Seismic Systems Inc.
Type	GI Gun 210 cu.in.
Specifications	105 / 150 / 250 cu.in. Generator 105 cu.in. Injector
Configurations	GI Mode no bubble pulse Harmonic Mode reduced bubble pulse 600 cu.in array (150/105 and 250/105)