Geometrics GeoEel Multi-Channel Streamer

Science Center Objects

The GeoEel is a multichannel digital streamer system, with hydrophones in a long, green hose. The streamer is towed like a long snake in the water from a vessel, and the hydrophones "listen" for and record the signals from the seismic sound source.

A coil of green hose on the deck of a ship at sea.

PCMSC's Geometrics GeoEel Multichannel Streamer on R/V Bold Horizon

Description

The Geometrics GeoEel is a solid, multichannel digital streamer system.  The system consists of a streamer power supply unit, analog to digital converters (one for each section of hydrophones), and streamer hydrophone sections.  These sections can be connected together to increase the length of the streamer and the number of channels.  Using the multichannel streamer to record reflections allows for one to identify subsurface structures meters to thousands of meters below the seafloor, depending on the sound source used.

Specifications

  • Manufacturer: Geometrics
  • Model: GeoEel Solid
    • 150 m @ 3.125 m hydrophone group spacing (6 solid 25 m sections)
      • 2 sections with bird coils
    • 50 m @ 1.56 m hydrophone group spacing (4 solid 12.5 m sections)
    • Tow cables, isolation & stretch sections
    • (12) Digitizers
  • Weight: 156 kg/100 m
  • Dimensions: 44 mm diameter
  • Power Requirements: ~120 VAC
A large wheel, bigger than a person, holds a long green hose wrapped around its drum.

GeoEel on its winch in the wareyard of MarFac

Operational Characteristics

  • Minimum Operational Depth: 10 m
  • Maximum Operational Depth: Streamer has a maximum tow depth of 35 m, but it can be used to record data in any depth of water.  Results will be dependent on the choice of sound source.
  • Sediment Type: Any
  • Limitations:  Length of the multi-channel streamer can vary from 50 m to many kilometers, and may be determined by how much the vessel can accommodate
  • Power Outputs / Freq. Ranges: 500 to 8000 Hz Bandwidth
  • Ship’s Requirements
    • Can be stored and deployed using a large streamer winch- footprint 8 ft by 8 ft
    • When stored without a winch, it requires 7 ft by 5 ft deck space

Additional Equipment Required

  • The multi-channel streamer requires a topside PC running the Geometrics Controller software to collect, display and record data.

The GeoEel hydrophone streamer is the “listening”/recording device for a seismic sound source.  The sound source is chosen based on the goal of the survey as well as the environmental conditions.

 

Photo of equipment sitting on the deck of a boat which is docked, and it's sleeting or snowing.

University of Washington's research vessel R/V Barnes is loaded with the USGS multichannel seismic system components GeoEel, Chirp, and boom plates. During the fieldwork, we collected multichannel sparker and towed chirp sub-bottom data in Puget Sound and multichannel boomer and towed chirp sub-bottom data in Lake Washington, in hopes of characterizing recent deformation and estimating earthquake recurrence on the Seattle Fault zone.