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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

November 10, 2015

AGU's First Ask Me Anything: Water Science and Management

AGU's first ever Reddit Ask Me Anything, features Dr. Alberto Montanari, editor in chief of Water Resources Research on 12 November, from 12:00-2:00 P.M. EST, via Reddit's r/science portal ...

November 5, 2015

Massive graphite discovery could be on the cards for NQ

Graphite is a mineral of immense potential and value - its purer forms sought out for use in mobile phone technologies and the batteries that power...

November 1, 2015

Australia's junior sector turns to crowdfunding

Australian junior miners have decided to battle the capital drought afflicting the sector by turning to the Internet to raise funds...

October 28, 2015

Saudi Arabia's mining sector to triple by 2030

Mining contribution to GDP to reach SR260 billion by 2030 and create more than 100,000 jobs for citizens ...

October 26, 2015

Grant enables pioneering research of vast river systems in Great Plains and Asia

It's hard to exaggerate the importance of rivers to sustaining life for animals and people...

October 16, 2015

INFOGRAPHIC: "Gold off to races?"

This week, gold made a significant technical breakthrough ...

October 15, 2015

BHP raising $6.5bn fresh sign of mining turnaround

The mining industry's big players are themselves slowly beginning to change tack...

October 7, 2015

Could rock formations along Alabama highways offer clues to climate change?

Making predictions about climate variability often means looking to the past to find trends...

October 2, 2015

Petrobras' pre-salt drilling confirms high quality oil potential in Carcará

The drilling of the third well in the Carcará area (Block BM-S-8) in the Santos Basin's ultra-deep waters...

October 1, 2015

Eni enters Mexico with the development of three oil fields offshore

Eni won with a 100% share a production sharing contract to appraise, develop and exploit the oil fields...

September 23, 2015

Frank Arnott Award honors exploration visionary

A new award named in honor of Frank Arnott, a visionary geophysicist from the United Kingdom, has been introduced to recognize innovation in visualizing and integrating exploration data.

September 21, 2015

300m-year-old volcanoes discovered near Mullingar

Geographically, Ireland is often likened to a saucer: upturned at its mountainous edges and flat...

September 17, 2015

True giants of mining: World's top 10 iron ore mines

The price of iron ore on Thursday turned positive amid new signs that China...

September 15, 2015

GIS and History: Using the Past to Inform the Present

Using the power of Geographic Information Systems to track trends in everything from...

June 26, 2015

Where Big Data Jobs Are In 2015 - Midyear Update

Professional, scientific and technical services, information (IT), and manufacturing are the three industries doing the most Big Data-related hiring as of June, 2015...

June 25, 2015

Coiled Tubing Drill Rig Modified for H Coil

Trials of a new Coiled Tubing Drill Rig are underway in Australia. These rigs use a continuous, flexible tube, rather than drill rods, for faster, safer drilling at just 50c per meter...

June 17, 2015

First gas production from L6-B in the Dutch North Sea

Wintershall is expanding its natural gas production in the Netherlands: the unmanned mini-platform L6-B has started to produce natural gas off the Dutch North Sea coast. The first so called "Minimum Facility”...

June 16, 2015

Worldwide water quality app hits the web

Former Copernicus Masters competition winner EOMAP has launched the first harmonised, high-resolution inland water quality monitoring service based on satellite data...

June 15, 2015

Results from hole AR-15-44b add substantial size to NexGen's rapidly developing Arrow zone

NexGen reported on assay results for angled hole AR-15-44b from the successful winter 2015 program at the Arrow zone on its 100% owned Rook I property, Athabasca Basin, Saskatchewan...

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.