Main directions / Engineering and geological investigations / Geo ecological monitoring / Geophysical surveys / Acoustic measurements

Geophysical methods for monitoring of the shelf geological medium allow implementation of the acoustic remote method of investigation of bottom deposit structure and composition into geological shelf research practice.

Acoustic measurements performed in shelf and inland water reservoirs are connected with solution of the following tasks:

• Geo ecological monitoring in shelf zones;
• Tracing and exploration of sea placers of hard mineral products;
• Engineering and geological continental shelf surveying for construction of engineering facilities and utilities;
• Support of engineering and geological works in the course of pipelining in inland water reservoirs and at river crossings;
• Sensing of trunk pipeline systems and evaluation of their repair;
• Search and sensing of man-caused objects on the sea bed and in the substrate;
• Control of the state of navigation fairways;
• Support of dredging.

The set of tools required for shelf high-resolution acoustic measurements includes:

• Digital high-resolution profile recorder (surface analyzer);
• Digital multi-channel acoustic system (TsMKS)

The profile recorder is designated for examination of the structure and composition of bottom deposits at the sea depth from 5 to 200 m. The survey depth along the bottom deposit section depends on the type of bottom deposits and may vary from 2 to 50 m. The profile recorder uses an electro dynamic source (effective water depths are from 1,5 to 50 m) and piezoelectric source working at central frequencies of 4 and 7 kilohertz. Resolution at the time of thin stratum picking is 0.15-0.3 м.

In the remote classification mode the profile recorder allows to divide bottom deposits into four lithologic classes:

• silts;
• clays;
• sands;
• coarse deposits and ledge rocks beats.

In the profile recorder assembly are two mounted aerial systems that can be installed on board a ship or boat. Power for the profile recorder is 220 v and 50 Hz. Power input 300 VA. Hardware weight is 30 kg. Aerial system weight is 20 kg.

Digital multi-channel acoustic system (TsMKS) is designated for investigation of bottom deposit structures in cases of much scattered sections with sea depths up to 200 m and has the following characteristics: depth of investigation along the section of bottom deposits from 10 to100 m; resolution when included in the wire exploder unit 1-2 m.

In the unit the 24-channel reception piezoelectric seismograph is used as the receiving antenna system; it allows to identify density and velocity characteristics of a bottom deposit section.

Receiving and emitting aerials are used in the tow variant in case of moving 20 – 50 m away from a carrier ship.

Digital multi-channel acoustic system (TsMKS) is powered from AC mains, voltage 220v 50 Hz. Mean power input 500 watt. Hardware weight is 50 kg. Low-frequency channel range of the acoustic system is 300 to 800 Hz and uses the sparker source “SPARKER” for emitting. For boosting the elastic wave is used the storage condenser GIT-5 with operating voltage stress of 1-5 kilovolt; the capacity of the storage condenser is 25-100 mF. The assembly for reception, processing and reflection of acoustic measurements includes the 24-channel booster (the Diogen firm) and the control module is PC Pentium 5 based .

Contacts / In top of page