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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

April 8, 2015

New data on DAP: SRTM 30m for Europe and Africa

Shuttle Radar Topography Mission (SRTM) 1 Arc-Second Global elevation data at a resolution of 1 arc-second (30 meters) are now available for Europe and Africa on the Geosoft Public DAP Server...

April 7, 2015

IBAAS 2015 symposium focuses on development of aluminium industry in China

The International Bauxite, Alumina & Aluminium Society (IBAAS) is hosting an international symposium on "The Development and Future of Aluminium Industry in China - Reality and Dream” November 25-27, in cooperation with the China Aluminium International Engineering Corporation Limited (CHALIECO) and Suzhou Research Institute for Non-ferrous Metals Co. Ltd (SINR)...

March 26, 2015

Medgold and Centerra Start Drilling at Lagares, Portugal

Medgold's first drilling campaign on the Lagares project in Portugal, a 3,000 metre diamond core drilling program, started yesterday targeting high-grade gold mineralization identified from recent channel-chip sampling. The Lagares project is joint ventured to Centerra Gold Inc...

February 27, 2015

Massive Amounts of Saharan Dust Fertilize the Amazon Rainforest

Every year, millions of tons of nutrient-rich Saharan dust cross the Atlantic Ocean, bringing vital phosphorus and other fertilizers to depleted Amazon soils. New study quantifies the connection between Earth's largest temperate desert and its largest tropical rainforest...

February 25, 2015

NexGen Drills Best Angled Hole to Date: Discovers New High Grade Zone at Arrow

NexGen Energy Ltd. announced ongoing results from their winter 2015 drilling program at their our 100% owned Rook I property, Athabasca Basin, Saskatchewan...

February 24, 2015

Phase II drilling underway on Kootenay's La Negra

Kootenay Silver Inc. announced that camp upgrades are complete and Phase II drilling has now commenced on its La Negra Silver discovery, contained within the Promontorio Mineral Belt in Sonora, Mexico...

February 23, 2015

Explorer Speaker Series at the PDAC

Geosoft's Explorer Speaker Series at the PDAC 2015 includes presentations on Peregrine's Chidliak Project and Cameco's initiatives to increase efficiency and 'harvest time' through data organization...

February 18, 2015

Largest Dam Removal in U.S. History Scientifically Characterized

The effects of dam removal are better known as a result of several new studies released this week by government, tribal and university researchers...

February 18, 2015

Exeter outlines the significance of its Caspiche Project water discovery

Exeter Resource Corporation has announced further positive results from the expanded water exploration drilling program for its Caspiche gold-copper project in northern Chile...

February 17, 2015

Earthstar Geographics Releases Arctic Ocean 15-Meter Satellite Imagery Mosaic

In response to the rapidly increasing demand for high quality geodata of the Arctic Ocean, Earthstar Geographics LLC has compiled a detailed satellite imagery mosaic of the entire region and released it in map projections optimized for visualizing the northern polar areas...

February 11, 2015

Geophysics and Geology together for Discovery: Geosoft at ASEG-PESA

Geosoft's program for the ASEG-PESA, February 15-18 in Perth, includes a workshop on practical geophysical workflows for resolving common problems in minerals targeting...

February 9, 2015

Pilot Gold Reports Final 2014 Results from Columbaz Discovery at TV Tower

Pilot Gold announced the final 2014 results from its third gold rich porphyry discovery at TV Tower, located 6.5 kilometres north of the Valley and Hilltop porphyries...

February 5, 2015

Coastal Gold finds the high grade

Coastal Gold has defined a high grade resource at its 100%-owned Hope Brook gold deposit in Newfoundland by developing a 3D model that has tighter constraints and focuses on higher grade drill results.

February 4, 2015

Non-seismic Geophysics

Finding Petroleum is hosting a half-day event on the role of non-seismic geophysical techniques. Are they coming of age? Reserve your space for this free event, being held in London, February 19.

January 27, 2015

Factors Driving 2015 U.S. Oil Output

Rig counts are a highly imperfect guide to future oil production but they are one of the few readily available statistics on oilfield activity so it is unwise to dismiss their importance entirely...

January 23, 2015

Will 2015 Break this ‘Dry Spell’ for New Discoveries?

Steve Todoruk, a broker with Sprott Global Resource Investments, explained in Sprott’s Thoughts recently why ‘juniors’ should look for new discoveries by drilling into the unexplored depths near existing mines...

January 20, 2015

Eni Wins Two Exploration Licenses in Norway

Italian oil and gas group Eni said on Tuesday it had won two exploration licenses in the Barents sea and in the North Sea in Norway...

What Lies Beneath: Detecting Bombs Under the Earth's Surface


Paul Lima

With the growth in global population, land for housing, business and recreation is in great demand. However, land that seems available might not be suitable for human use if it has served as a battleground in warfare or if the military has used it for practice ranges or the disposal and destruction of munitions. Land mines and unexploded ordnance (UXO) contaminate more than 83 countries. When munitions are fired but don't explode or only partially explode, they are categorized as UXO. Battlegrounds in the First and Second World Wars are a typical example of UXO fields. UXO can also be found in regions of developing nations in the 20th and 21st centuries where civil or proxy wars have been played out (such as occurred in the Cold War). These fields are scattered around the globe. In the U.S., more than 2,000 closed or transferred military ranges are believed to contain UXO. Before land with buried UXO can be reclaimed for housing or other projects, the UXO must be found and removed.

The UXO Detection Challenge

Locating and removing UXO can be complicated, time-consuming and costly. In Europe, there is growing advocacy for UXO and mine clearance, with stronger partnerships emerging between UN, community and government agencies to set out plans for UXO removal. Standard UXO detection techniques in Europe generally make use of traditional grid-pattern borehole drilling. In North America, the civil engineering arm of the military is in charge of UXO clearance. UXO teams in North America, working under guidelines set by the U.S. Army Corps of Engineers (USACE), collect and analyze data for UXO removal with the aid of geophysical techniques and specialized software.

"If we had to remove bombs from flat homogeneous areas such as sand bars, we could easily detect the UXO with geophysical sensors and they would stick out like sore thumbs, but that's seldom the case," says Elizabeth Baranyi, Earth Sciences application programmer with Geosoft.

In areas that are rough or wooded or where the soil is magnetic or covered with lava flow that has a high iron content, sensor readings become busy, making it difficult to distinguish between geological and UXO signals. Other buried objects of similar size, such as a metallic grid, can further complicate the interpretation of data. The discrimination between UXO and non-UXO is a cost concern that is a subject of ongoing research.

Precision and data quality is critical in UXO surveys; all external factors must be minimized as they can interfere with the reading of UXO signals. Examples include steel-toed boots, jangling keys, flopping cables, and even inconsistent walking speeds.

Before the introduction of software, contractors used instrumentation to locate UXO and dig where they found peak readings. This method was knows as "Mag and Flag." "However, the peak isn't necessarily right above the UXO," says Baranyi. "It depends on the size, shape, depth and dip angle of the UXO, and, in the case of magnetic surveys, the magnetic field of the earth. You can dig at the peak and miss the target by a few centimeters, or you might spend a lot of time digging for objects only to find they aren't UXOs." The aim is to improve the quality and the discrimination methodology of the UXO survey data in order to save time and money while ensuring confidence in the outcome.

Since there could be a large number of ordnances in a small area, or a few deadly ones spread over a large area, trying to pinpoint UXO locations is like looking for needles in a haystack or, as in geological exploration, looking for a rare mineral that might or might not be present. But the process is getting easier, thanks to advanced geophysical techniques, computer-aided analysis, and 3D modeling.

Initial Planning

Exploring for UXO typically starts with initial geophysical planning. A geophysical investigation system capable of pinpointing buried UXO must have four fully integrated components:
  • Personnel experienced in the theoretical and practical aspects of detecting UXO and discriminating between UXO and non-UXO. The selection and utilization of geophysical equipment require qualified, experienced individuals.
  • Geophysical instruments that are well-suited to detecting buried UXO, taking into account site-specific factors such as the type and depth of the target UXO, terrain, vegetation, and geologic and cultural settings.
  • Navigational accuracy and precision, that is, the ability to locate, within the centimeter range, the geophysical data in relation to other known points.
  • Procedures for analyzing and interpreting geophysical data generated by geophysical instruments.
If any of the above four components are lacking, the overall geophysical system will not be able to locate UXO precisely. It's important to plan and integrate all aspects of a geophysical investigation carefully and not start fieldwork prematurely.

Geophysical Techniques

Geophysical investigations performed at sites that may contain ordnances can be divided into three categories:
  • Geophysical sampling performed at representative portions of a site to characterize a larger area. The objective here is to characterize the distribution, type and condition of UXO across a site in a way that is both economic and accurate.
  • Geophysical mapping performed across an entire area suspected of containing UXO. The objective is to locate all detectable UXO that meet pre-determined criteria such as type, size, composition and depth.
  • Geophysical interrogation performed at specific locations or small sites to obtain additional target information beyond that gathered by initial investigations. Although slow and expensive, this technique can yield important information about the size, depth, composition and configuration of individual targets or target clusters.
Overall, the objective of such geophysical investigations is to locate UXO while minimizing the number of non-UXO geophysical anomalies. Since unearthing buried munitions is expensive, the data collected must be scrutinized carefully, and computer software is used to help with the analysis and for quality control.

Software for UXO

UXO investigations require the use of digital geophysical mapping software and depend on quality field data. The software is used to minimize the risk of inconsistent data and faulty decision-making. For instance, data filtering algorithms can level and smooth data, eliminate background noise, and enhance geophysical real anomalies that have UXO-like signatures. Software can also help convert high volumes of geoscientific data into knowledge that supports accurate UXO mapping and target detection and narrows selections to a final target list.

As part of its mandate, the U.S. Army Engineer Research and Development Center (ERDC) has been funding the development of technologies for the detection and discrimination of UXO in an effort to improve the process.

One of these initiatives, a co-operative agreement between Geosoft and the USACE, Huntsville Center, has resulted in industry-standard tools to boost efficiency and accuracy in UXO investigations. These UXO Quality Control and Quality Assurance (QAQC) software tools, developed within Geosoft's Oasis montaj platform, are being used at UXO sites around the world to improve data consistency and detection methods.

Beyond quality control, software is essential to UXO project management insofar as it allows work to be recorded, both for review and future audit. With all UXO investigations, it's necessary to demonstrate that the site was cleaned up as well as possible and that everything that was conceivably detectable based on available scientific and technical capabilities was in fact detected.

In short, software and quality control measures are essential both for the interpretation of data and the creation of standardized analytical processes. With advancing techniques and the right software, it's possible to manage UXO projects effectively, saving limbs and lives in the process.