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Earth Explorer is an online source of news, expertise and applied knowledge for resource explorers and earth scientists. Sponsored by Geosoft.

News & Views

News Archive

December 7, 2016

Geosoft introduces IP and resistivity inversion in VOXI Earth Modelling

Geosoft has added induced polarization and resistivity data inversion to its VOXI Earth Modelling 3D inversion software service. Geoscientists are now able to create detailed 3D models of conductivity and chargeability from IP and resistivity survey data with VOXI. The resulting models can assist in interpreting and targeting regions for mineral and environmental applications...

December 5, 2016

Mexico's Deepwater Round Exceeds Expectations

Some of the world's biggest oil companies showed up Dec. 5 and agreed to invest on the Mexican side of the Gulf of Mexico, proving that deepwater exploration still has a pulse despite challenging market conditions...

November 30, 2016

Magnetic inversion results for Ngamiland available for download

A regional-scale geophysical inversion of magnetic field data in the Ngamiland region of northwestern Botswana is now available for download from the Botswana Geoscience Portal, a partnership initiative of the Botswana Geoscience Institute, industry sponsors and Geosoft...

November 30, 2016

LIGO Resumes Search for Gravitational Waves

After a series of upgrades, the twin detectors of LIGO, the Laser Interferometer Gravitational-wave Observatory, have turned back on and resumed their search for ripples in the fabric of space and time known as gravitational waves. LIGO transitioned from their engineering test runs to full science observations at 8 a.m. Pacific Standard Time on November 30...

November 9, 2016

International Volcano Scientists Unite

For the first time, the United States will host the international Volcano Observatory Best Practices workshop, previously held only in Italy. The workshop will take place this month in Vancouver, Washington. It is designed specifically for volcano observatories around the world and their staff to exchange ideas and best practices with each other...

October 4, 2016

USGS Assesses Mineral Potential for Sagebrush Habitats in Six Western States

USGS has completed a comprehensive assessment and inventory of potential mineral resources covering approximately 10 million acres of Federal and adjacent lands in Idaho, Montana, Nevada, Oregon, Utah and Wyoming...

October 3, 2016

Uganda Targets Up to U.S.$100 Million for Mineral Exploration

Uganda is well endowed with mineral resources and, like many naturally-gifted African countries, is becoming keen on ensuring that these resources play a transformative role in its long-term structural transformation dream - the Vision 2040...

September 9, 2016

Small-Scale Fishers Get A Big Boost With First-Of-Its Kind Impact Investment Fund

Conservation organization Rare announces the Meloy Fund for Small-Scale Fisheries at Our Ocean Conference. The Global Environment Facility, one of the largest funders of conservation worldwide, will be investing $6 million into the fund...

September 1, 2016

Scientists take to the skies to track West African pollution

Scientists operating research aircraft over West Africa have detected organic materials in the atmosphere over a number of urban areas, contributing to concerns of the rise in pollution across the region...

August 17, 2016

New IGS Xplore prospectivity maps for Botswana

International Geoscience Services have released a series of base metal prospectivity maps for the Ngamiland District of northwestern Botswana using free geodata available on the recently-launched Botswana Geoscience Portal, hosted by Geosoft. The maps identify favorable areas for copper, zinc and lead mineralization using geological, geochemical and geophysical datasets downloaded directly from the portal.

August 11, 2016

NexGen Makes New High Grade Discovery

NexGen Energy reported the discovery of a new high grade zone of mineralization 4.7 km northeast of the Arrow Deposit as part of an on-going summer drilling program on its 100% owned, Rook I property, Athabasca Basin, Saskatchewan...

August 10, 2016

Rampion UXO Disposal to Take Place This Week

E.ON has confirmed that the two unexploded devices, detected along the Rampion offshore cable route will be safely disposed this week following the consultation with the Marine Management Organisation...

August 9, 2016

Diamonds In The Rough: E&Ps Find New Reserves In Mature Basins

The oil industry’s history demonstrates clearly that new plays and prospects have long been found in mature basins that were thought to be well on the way to being squeezed dry. Through the acquisition of new data, developing new concepts and coming up with fresh interpretations, long-producing basins around the world from the North Sea to Malaysia have continued to reveal new riches...

August 8, 2016

Northern Shield Identifies High Quality VTEM Targets at Séquoi

Northern Shield Resources announced the results of the interpretation and modelling of the VTEM survey from the Séquoi Property in the Labrador Trough of Quebec . Séquoi is owned 100% by Northern Shield and is being explored for Noril'sk style Ni-Cu-PGE massive sulphides. After geophysical modelling and interpretation of the VTEM data from Séquoi, six VTEM anomalies of significant interest have been identified...

August 3, 2016

Rio Tinto tailors big data drive to copper

Rio Tinto will put the weight of an exploration big data push and its newly-formed Growth and Innovation group behind its desire to identify a "tier 1" copper asset. Speaking at the annual Diggers & Dealers conference in Kalgoorlie, Growth and Innovation group executive Stephen McIntosh said Australia was "overdue for a tier 1" mineral discovery of any type...

August 1, 2016

Tetra Tech Awarded $200 Million Navy CLEAN Contract

Tetra Tech announced that it has been awarded a $200 million, single-award contract by Naval Facilities Engineering Command (NAVFAC) Atlantic. Through the Comprehensive Long-term Environmental Action Navy (CLEAN) contract, Tetra Tech will provide environmental engineering support services to installations within the NAVFAC Atlantic Area of Responsibility...

May 3, 2016

NATO Science for Peace and Security (SPS), MODUM Partners announce "Young Scientist Summer School on Sea Dumped Chemical Weapons"

This international project cooperates closely with CHEMSEA (Search and Assessment of Chemical Weapons) Project for and sharing and knowledge transfer...

April 12, 2016

Monday mad rush for gold stocks

Renewed optimism about the outlook for gold saw investors pile back into gold stocks, pushing many stock to 52-week highs in heavy volumes...

April 11, 2016

Medgold Resources: Continues to Expand the Boticas Gold Project, Portugal; Proposes $200,000 Private Placement

Medgold Resources is pleased to announce new assay results from contiguous rock-chip sampling from the Limarinho South zone at its Boticas gold project in Portugal, which include a highlight of 6.0m @ 5.7 g/t Au...

April 8, 2016

De-carbonizing our energy sector

Nuclear energy currently provides around 11 percent of the world's electricity. China, the European Union, the United States, India, Russia, South Korea, and other nations’ have major existing fleets...

April 1, 2016

Follow-Up Drilling Results Indicate Wide Gold Zones at Hendricks Gold Discovery

Gascoyne Resources Limited announced that it has received the final assay results from the 10,000 metre aircore exploration drilling programme...

March 26, 2016

The Oil Market Is Finally Hitting Its Breaking Point

After a significant reduction in investments over the past two years, oil companies can no longer overcome the production declines from legacy wells...

March 15, 2016

N-Sea Expands into the French Offshore Wind Industry

Subsea IMR provider, N-Sea, has signed a letter of intent with CERES Recherches & Expertise Sous-Marine and TechSub Industrie Environement, to provide subsea survey, installation and remediation services to the French offshore wind industry...

March 9, 2016

PDAC 2016 Convention Exceeds 22,000 Attendees

Optimism and opportunity abounded at the PDAC 2016 Convention of The Prospectors & Developers Association of Canada in spite of recent industry challenges...

March 3, 2016

6 Alpha Launches EOD Contracting Division

6 Alpha Associates, a specialist risk consultancy practice, with expertise in the assessment and management of unexploded ordnance, has launched a dedicated explosive ordnance disposal division...

Guidance on geophysical classification for UXO

by Kylie Williams on February 27, 2015 Library

Resources providing guidance on geophysical classification for munitions response projects and free Internet-based training are available on the Interstate Technology & Regulatory Council website at

Finding and clearing buried grenades, artillery shells and other munitions – also known as unexploded ordnance (UXO) – can be difficult, expensive and time-consuming. The goal is to ensure public safety and safeguard the environment and that means cleaning the site as thoroughly as possible. A key challenge in UXO investigations is discriminating between UXO and harmless metallic objects. Is it a bomb or a pop can?

New approaches for geophysical classification of UXO are helping to save time and money by reducing the excavation of harmless debris. The methods involve the use of electromagnetic sensor data to measure, analyze and classify metal objects in the ground. Geophysical classification has proved especially useful in differentiating between hazardous munitions and metallic debris, reducing the number of harmless items excavated by up to 80%.

These and other advantages are explained in a series of fact sheets on Geophysical Classification for Munitions Response (GCMR) published by the Interstate Technology & Regulatory Council (ITRC), a coalition of private- and public-sector organizations based in Washington, D.C. The fact sheets and other resources published by the ITRC provide useful information for scientists, engineers, and environmental professionals, as well as state and federal regulators, project managers, and technical staff involved in munitions response projects.

Geophysical Classification Fact Sheets

The latest update to the GCMR fact sheet series, published in October 2014, presents the results of the Geophysical Classification Pilot Program, initiated by the U.S. Department of Defense (DoD). At multiple military sites around the U.S., geophysical classification was used to identify targets of interest, in some cases with 100% accuracy.

The first fact sheet, published two years earlier, gave an overview of the geophysical classification process and explained how the geophysicist’s ability to estimate the depth, size, density, wall thickness, and shape of each buried item is crucial in determining whether an object should be excavated or left alone.

The second fact sheet, published in June 2013, explained the geophysical classification technology and process, the types of terrestrial sites where this technology may be applicable, and data quality considerations. The document notes that there are three steps involved in geophysical classification:

First, advanced electromagnetic induction (EMI) sensors are placed on the ground at locations where potential UXO targets have been found with standard mapping geophysical surveying methods. A pulsing electric current produced by the sensors generates a magnetic field which interacts with any metal objects buried nearby to create a secondary magnetic field. Then the primary inducing field is quickly turned off and the secondary field produced by the metal objects is recorded.

The whole process takes about thirty seconds during which time thousands of spatial and temporal measurements are recorded from various angles and locations. These EMI responses are influenced by the size and shape of each object and its location relative to the sensor.

Geophysicists and munitions response teams are building a library of EMI responses with which to analyze and classify new objects using Geosoft Oasis montaj and UX-Analyze, the software most commonly used in the UXO industry to classify anomalies.

A partnership of Geosoft with the U.S. Army Corps of Engineers (USACE), the Environmental Security Technology Certification Program (ESTCP), Acorn Science & Innovation (and previously Leidos Inc.) and the UXO research community has resulted in new workflows, such as UX-Process and UX-Analyze, and overall improvement in technology for increasing accuracy and reducing risks in UXO detection and environmental clean-up.


Overseeing the geophysical classification process presents a unique challenge for regulators. Toward that end, the ITRC’s fact sheets outline the roles of state and federal environmental regulators, as well as project managers, technical personnel, contractors, customers, suppliers, scientific experts, stakeholders, and so on.

The ITRC stresses that communication within teams and among regulators, scientists, stakeholders, are essential in the safe, efficient application of geophysical classification for munitions response.

For a more complete picture on the practical reality of classifying unexploded ordnance using geophysics

Download a technical poster on Geophysical Classification of UXO


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