U.S. Department of the Interior

U.S. Geological Survey

September 2008

Field Demonstrations in Anthropogenic Waste or Unexploded 

Ordnance Sought for USGS Marine Induced Polarization (IP) 

Streamer System Technology 

Printed on recycled paper

Description of the Marine IP Streamer System

The Marine IP streamer system takes its electrical 

measurements from a moving vessel (fig. 1) and consists of a multiconductor cable with elaborate electrical shielding, special nonpolarizing detector electrodes, 

optical isolation, pre-amplification, floating ground, 

and other noise-suppression techniques. The streamer 

also has active galvanic electrical (titanium) transmitter 

electrodes that are used to inject current directly into the 

seafloor. The acquired data are converted to digital form 

and processed onboard the towing vessel. Postprocessing, 

analysis, and 2D and 3D data-representation development 

follow the data-acquisition phase. 

Initial field demonstrations focused on the 

technology that enables the 

streamer to detect placer 

heavy minerals, certain 

clays, and disseminated 

metals on the seafloor from 

a moving vessel. During 

sea trials, it was realized that the system also 

detected metallic debris 

on the seafloor, even when 

buried beneath meters of 

inert mud. See Types of 

Visual Information available from IP Streamer on 

page 3.

Since 2001, researchers at the U.S. Geological Survey (USGS) 

have teamed with industry partners to explore the commercial 

applications of the USGS-patented (2001) Marine Induced 

Polarization (IP) Streamer system that has the ability to 

rapidly map very low percentage mineral and metallic particle 

distributions on and beneath the seafloor in three dimensions 

and with high resolution. 

Cable Depressor

Drogue

Multi-Component

Cable

Data-Acquisition

System on Board TRANSMITTER ELECTRODES–Titanium wire

RECEIVER ELECTRODES

COMMON-MODE REJECTION DIFFERENTIAL PRE-AMPLIFIERS

HEAVY PLASTIC SHEATH

EXPLANATION

Marine IP Towed Array

7.5

7.5

7.5

7.5

7.5

7.5

7.5

7.5

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DISTANCE, IN METERS (not shown to scale)

NOT TO SCALE

Figure 1. The Marine IP Streamer system sweeps across the seafloor while towed behind the research vessel.

Fantail of NOAA research vessel Ferrel

In 2007, the IP Streamer was licensed to Williamson & 

Associates of Seattle, Wash. (Williamson), as the result of 

the partners earlier Cooperative Research and Development 

Agreement involving the technology. Williamson, a diversified geophysical consulting firm and Zonge Engineering 

and Research Organization of Tucson, Ariz., an electrical 

engineering company with broadband electrical and 

electromagnetic expertise, field tested the IP Streamer 

technology in a large-scale commercial mineral survey 

off the coast of South Africa in 2007. See Bismark Mineral Identification Trials on p. 3.

In 2008, the partners are developing field testing 

opportunities for waste and ordnance identification. 
Cost-Effective Anthropogenic Waste & Ordnance Detection

The USGS IP Streamer technology is capable of providing a cost-effective method for identifying and tracking sewage outfalls, 

garbage-barge dumps and industrial waste that contain metal content. The Comparison Table (page 4) contrasts the IP 

Streamer capabilities against other traditional methodologies for seafloor mapping.

The offshore regions in the 200-mile wide U.S. Exclusive Economic Zone equate to more than 3 million square miles 

(~8 million square kilometers) of “land” that has not been scientifically mapped, categorized, or explored below the watersediment interface. In addition to the lack of scientific and mineral information about the Economic Zone, many areas have 

been used as urban-waste dumps for centuries. As a result, these 

waste deposits are causing pollution, which is affecting human health 

and ecosystem balance, as well as creating navigation hazards. 

These issues need to be better understood, quantified, and subject to 

remediation, when and where possible.

USGS research and laboratory measurements show that anthropogenic 

waste (such as sewage outfalls, garbage-barge dumps, and industrial 

waste) has significant metal content, which is self-reducing because 

of the associated bacterial content to metallic or metallic-sulfide form. 

These deposits are also generally moving due to tides and longshore 

ocean currents. Furthermore, metallic particles in the sewage 

(especially) and waste (in general), are usually extremely fine. These 

particles maximize surface area versus volume percentage content, 

and, thus, increases its IP detectability for very small percentages. 

USGS laboratory-scale studies also indicate a strong correlation 

of a specific multifrequency IP spectral 

signature for identification of this type of 

waste and suggest a potential ability to map 

its movement over time through additional 

surveys.

Example of a distinctive and unusual “flat” IP spectra from a Long Island Sound sediment sample with significant 

sewage content (high carbon, anoxic, finely disseminated sulfides)

A scientist performs 

laboratory analyses of 

Clostridium-infected 

samples that were 

extracted (dredged) 

from Long Island Sound, 

N.Y. These anoxic 

sediments were derived 

from sewage that has 

been dumped into the 

Connecticut River over 

the past centuries. 

A dredge sample 

from one of the Long 

Island offshore wastecollection areas was 

measured in the 

laboratory, and the 

distinictive IP spectral 

signature is shown here.

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Comparisons of Existing Seafloor-Mapping Technologies

Technology Physical principles Potential targets Strengths Limitations

Marine IP Streamer 

system

Induced polarization; 

IP spectra; resistivity

Sewage; industrial waste; buried unexploded ordnance; nonferromagnetic 

metals; titanium-rich sands; buried 

shipwrecks; freshwater incursion; 

shallow bedrock hazards; disseminated 

sulfides

Detects very small volume-percents; 

detects small, buried objects; 

target focused; uses three physical 

parameters; images multiple layers; 

high lateral resolution; can “see” below 

mud layer; covers large areas quickly

Must keep streamer on the seafloor

Resistivity Resistivity contrast Freshwater incursion; shallow bedrock Can use a floating streamer; small risk of 

hardware damage

Requires large volume percentages of 

freshwater; poor resolution; seawater is 

highly conductive

Sidescan Velocity contrast Discrete objects on seafloor; seafloor 

topography

Target focused; wide synoptic view Does not penetrate seafloor; surface features 

only

Subbottom profiling Velocity contrast Subbottom stratigraphy Target focused; good resolution Requires substantial velocity contrasts; cannot 

detect small, buried objects

Magnetics Magnetic susceptibility Ferromagnetic materials; iron ships Simple technology Not target focused; poor resolution

EM Resistivity contrast Deep hydrocarbons Can supplement seismic information in 

hydrocarbon exploration

Requires large volume-percentages; seawater 

is highly conductive; poor resolution

Radiometrics Radioactivity High-potassium seafloor sediments; 

radioactive ordnance

A different physical property Extremely limited penetration (top 1–2 

centimeters of the seafloor sediments)

To discuss possible demonstration sites or to find out more about this technology, contact:

Jeff Wynn, PhD

U.S. Geological Survey

Vancouver, Washington

Phone: 360-993-8919

jwynn@usgs.gov 

Michael Williamson, PhD, CEO

Williamson & Associates

Seattle, Washington

Phone: 206-285-8273

mikew@wassoc.com

Technology Transfer

USGS Office of Policy & Analysis

201 National Center

Reston, VA 20192

Ph. 703-648-6616

The scientific principle behind the electrical streamer 

is that IP is a surface-effect electrochemical methodology 

that is particularly sensitive to low-volume percentage, 

finely disseminated minerals, and metallic debris. Because 

of the signature nature of most anthropogenic waste, 

the technology permits simultaneous accurate mapping 

of various types of underwater debris with a single 

collection. An example of this is its ability to differentiate 

sewage outfalls from industrial-waste debris and their 

respective locations.

Finally, the equipment utilized in the IP Streamer 

identification is compact and can be deployed from almost 

any type of boat or vessel on the water’s surface, thereby 

taking advantage of a municipality’s or entity’s existing 

water-vehicle infrastructure. 

Summary

USGS and its partners, Williams & Assoc., and Zonge 

Engineering, are interested in doing full-scale testing to 

map underwater environmental contamination in ecologically sensitive rivers, bays, estuaries, and sounds with known 

environmental issues related to human and industrial 

waste. The partners are also looking for field-demonstration opportunities that could include metallic debris 

(such as unexploded ordnance) or other metal-containing 

materials which would exhibit an IP response, 

as described in the USGS patents: U.S. Patents 

6,236,211 B1 (May 2001); and 6,236,212 B1

(May 2001).

For additional articles discussing and 

contrasting the technology from existing 

underwater imaging systems, see: 

http://volcanoes.usgs.gov/jwynn/5offshore.html

Capabilities of the Marine IP Streamer

The test in the Bismarck Sea demonstrated that 

the system could detect widely dispersed sulfide haloes 

surrounding massive sulfide (ancient “black smoker”) 

deposits at depths as deep as 3,500 meters.

During the 6 weeks that the technology was deployed 

in South Africa, the partnership and its mining-company 

client gathered information on 1,200-line kilometers of 

ocean floor and generated about 830,000 IP and resistivity 

measurements, which were sampled simultaneously at 

four to seven different depths. 

The study confirmed that the USGS Marine IP 

Streamer system technology could:

•	 Verify that the paleo channels, which the company was

mining on land, can be mapped along and beneath the

seafloor;

•	 Identify the existence of similar mineral profiles of

interest to the company that had not been tested by the

client with vibracoring; and

•	 Establish a 3D vertical distribution for minerals of interest by pinpointing IP anomalies to a depth of 20 meters,

which indicates that mineral resources exist below the

test zone area.

Author~~Jeff Wynn

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NOAA vessel R/V Ferrel (fig. A) cruises off Cape Fear, N.C., 

gathering marine IP data. Figure B shows the ship’s tracks 

being monitored by scientists in realtime via an onboard 

computer. The reddish track plotted on the bathymetric 

map displayed on the monitor repeatedly crosses a 

paleochannel, an ancient river from the last glacial 

low-water period known to host heavy placer minerals. 

Figure C shows a similar track from the Mississippi 

Mineral Resource Institute vessel R/V Kit Jones as it 

conducted a marine IP survey in the gulf of Mexico. Figure D shows two types of data collected off Gulfport, Miss. The Ch1 Phase 

plot shows the IP metallic mineral response from beneath the seafloor; the Ch1Resis plot shows the resistivity profile at a set 

depth of several meters beneath the seafloor (predetermined by scientists prior to the survey by setting the array spacing). 

As depicted in the Cat Island Marine IP Survey graph, the resistivity profile denotes a “metallic object” where a bronze 17th century 

Swedish cannon was known to have been dredged. The “metallic object” gives an IP anomaly and a corresponding resistivity low 

(the anomaly was initially detected about 20 meters from the object). The graph also shows the profile of an area having “filled 

trenches.” These are previously dredged ship channels that were filled over time with sand and/or seafloor material when the 

seafloor was disturbed during hurricane and tropical storm events. The profile of filled trenches shows that slightly higher porosity 

gave rise to lower resistivity; therefore, no IP anomaly was detected.

Track of R/V Kit Jones

CAT10

CAT7

CAT6

CAT5

CAT3 CAT4

CAT2

Cat Island

89°00’

30°22’30“

30°15’

N

15,000 FEET

0 5,000 METERS

0

B

D

Sample of Visual Information 

Developed by IP Streamer Collection

A

C

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