The paper from Geotech Ltd. has been awarded as the Best Paper in the Mining and Geothermal sessions at the 2015 SEG annual meeting in New Orleans: “Airborne Inductively Induced Polarization effects in and their removal from the VTEM data from Mirny, Russia”.
As the Committee Chair says: “Out of all the papers presented, it was voted as highest ranking by the session participants”.
The paper is about airborne inductively induced polarization (AIIPTM) effects, which is expressed in the form of numerous negative transients, and observed in the VTEM helicopter time-domain EM (TDEM) data from Mirny, Russia. VTEM data reflect mainly two physical phenomena in the earth: i) electromagnetic induction and ii) airborne inductively induced polarization (AIIP) related to the relaxation of polarized charges in the ground. Typical AIIP effects in the VTEM data from Mirny corrupt only the early to mid-time channels, from 55 microsec to 400 microsec. Moreover, the earliest few time channels, from 18 microsec to 48 microsec, are not affected by AIIP, because the IP effect takes a finite time to build up. Cole-Cole analysis of the AIIP affected VTEM data showed that the frequency factor and the time constant are close to 0.8 and 0.0001s, respectively. Since the earliest time channel data are not affected by AIIP, the resistivity of the shallow ground can still be precisely determined. As a result, the purely inductive VTEM decay can be accurately modelled and used to remove the AIIP effect from later time-channels.
by Gemma Barson, Oct.30, 2015
A new study by the U.S. Geological Survey and university researchers that was published earlier this year has discovered that of the 94,870 people living in tsunami hazard zones in northern California, Oregon and Washington state, about 21,500 would not have time to reach higher ground were a tsunami to hit their community.
For many communities and local authorities this has led to an increase in demand for vertical evacuation structures that would enable residents to evacuate safely without having to seek higher ground (perhaps in the form of a beam type structure, or the fortification of an existing high building). However, more important issues thrown up by this study are that the existing infrastructure within these communities are so old and potentially structurally unsound that, were a tsumani to hit, bridges would crumble and dams would fail, blocking the potential escape routes of tens of thousands of individuals and leading to significant loss of life.
This leads to a huge assignment for geophysicists who have been tasked with utilizing innovative new technologies that have developed in the field of passive seismic to image the subsurface and the incredible details that these can pick up in a non-intrusive way. Whilst it was first adopted (and still has very lucrative applications for) the sourcing of underground oil wells and other vital resources, passive seismic near-surface geophysics can also be applied in other incredibly useful ways. It can be used to ascertain the ways in which passive sources (such as nearby train stations or large car movement on a highway) can impact both on earth movements and the surface of the earth’s structure, as well as ascertaining the impact that these have, particularly on aging infrastructure such as these bridges, dams and levees. It is clear that near-surface applications are both increasing in number, and that their societal value only continues to rise.
The Practical Considerations
The practical considerations that surround the field of passive seismic research are huge. Practitioners can choose to either temporary arrays deployment or, if they want to permanently monitor the seismic changes in a particular location, they can choose permanently installed sensors: there are, of course, pros and cons associated with adopting both systems. The largest technical risk is the sensitivity of the system, and how it will be negatively affected by any external noise and change, whilst financial implications are also a huge concern. Because passive seismic imaging is a quickly growing technology, it can also be very expensive to undertake. The purchasing and maintenance costs of the equipment is huge, particularly when the costs of the vehicular support that is needed to transport the equipment and access remote monitoring locations, as well as the costs of insuring and protecting all of that equipment are taken into consideration. These costs could vary considerably depending on where you are based, and where you choose to purchase your equipment, with technological hardware and software, and any related insurances, generally being considerably more expensive in Europe (particularly in the UK) than in North America.
The Society for Exploration Geophysicists have recently announced their new president as John Bradford: a specialist in the field of passive seismic research and very vocal about the potential wider implications that the new technologies surrounding the field can have. It seems that under Bradford’s leadership, focus throughout the society will shift to focus on passive seismic research, to the benefit of those working within the field. Monitoring failure cases are likely to be minimized as the technology involved in the process develops, and this will only make it easier to ensure that the vital infrastructures on which all of our communities depend can be maintained and updates as necessary.
Climate change is happening, and more and more communities are under threat from tsunamis, increased earthquakes, and other natural disasters. By deploying passive seismic monitoring to help us best understand how to strengthen our infrastructure and ensure that our bridges, dams, and other vital services can be rebuilt or repaired in such a way that will minimize the impact of these natural disasters, we can use passive seismic systems for the benefit of our greater communities.
“Global Business Reports” (GBR), who provides information about all aspects of the hydrocarbon, Pharmaceuticals, Chemical, Energy, Minerals, Mining and the Metallurgical industries around the world, has published an interview with the director of an airborne geophysics Kazakhstan-Canada joint venture as part of GBR research on the mining industry in Kazakhstan, which will be published in Engineering and Mining Journal in September 2015.
10 questions and 10 comprehensive answers about KazGeotech, its achievements and plans.
KazGeotech survey for Rio Tinto (rus):
by Michael Burns, President, Pioneer Exploration Consultants Ltd. on July,11, 2015
Pioneer Exploration Consultants Ltd. is a Canadian based geological consulting company that is quickly emerging as a leader in mining and exploration related UAV-based survey technology. Starting in 2014, they designed and built in-house a multicopter UAV-MAG™ survey system, and flew the first ever 590 line km multicopter-based survey.
Rather than waiting for a turn-key UAV based magnetometer system to hit the market, Pioneer came up with the idea of designing and building their own…
“Starting in the summer of 2014, we combined a proven UAV platform with a potassium vapor GSMP-35A magnetometer, resulting in a system with excellent performance specifications and survey capabilities. The UAV is a multicopter flight platform, chosen based on its payload capacity and flight time of about 30 min. The GSMP-35A potassium vapor sensor package is a proven airborne magnetometer with 0.0001 nT resolution, 0.3 pT sensitivity and 10 Hz sampling. The sensor package includes an ultra-light weight laser altimeter, GPS, and an IMU (inertial measurement unit) to record the sensor’s velocity, orientation and XYZ movement. The result was our UAV-MAG™ system which can fly up to 70 line km per day at an all in cost to the client of less than $100 per line km. Mobilization costs are the same as getting a person on site with 100 pounds of gear, due to the light weight and compact size of the UAV-MAG™, so rather than being a major cost addition to the survey, it’s becomes an insignificant expense.
To our knowledge, our survey costs are at least $40.00/ line km lower than anyone else on the market. This becomes a significant advantage for our clients, letting them put more resources into ground, and that’s huge for them.
Example of first vertical derivative results from two sample surveys, line spacing 50m, height 45m.
Our initial design focused on achieving three main goals:
1) To reduce magnetic interference of the flight platform in order to collect high quality magnetic data.
2) Create a system that is both reliable and flexible enough to fly a mag survey and collect aerial photos for orthoimagery and digital elevation models in the same day.
3) Create a highly portable system with the ability to fly a survey safely and simply in any terrain and under challenging weather conditions.
We achieved the first goal by employing a “towed bird” sensor configuration. The sensor is slung below the craft by a special designed light weight mount system, allowing sufficient craft-sensor separation and achieving low drag and no noticeable reduction in flight time. The remaining requirements pushed us away from fixed wing platforms and into multicopters for a number of reasons. With the UAV-MAG system, we can launch from the middle of a survey grid in heavily forested, steep terrain and not worry about takeoff and landing. Once in the air, the UAV-MAG™ takes care of the rest by flying the survey autonomously and returning home for landing. We found this invaluable for remote surveys. The small size of the platform, compared to a fixed wing system allows fast flight launching and easy transport. We can carry our fully flight-ready system by hand, ATV or vehicle, and launch within minutes. No complicated launching platforms, or landing fields required. What we have created is a truly versatile survey platform for multiple sensor packages, essentially a Swiss Army knife UAV, and our clients so far have been extremely pleased with the results and reduced survey costs.”
-Michael Burns, President, Pioneer Exploration Consultants Ltd.
For more information about our UAV-MAG™ Surveys, or to request a quote, please contact Michael Burns at: Michael.firstname.lastname@example.org
The Astana International Mining and Metallurgy Congress (AMM) (17-18 June) jointed political, business, financial and scientific leaders of the mining and metallurgical industry from many countries. The main goals of the congress was development of partnerships, introduction of technological innovations, attraction of investments and development of the country’s mining act.
The congress was held in the Palace of Independence. The world leader in airborne geophysics Geotech Ltd. together with the JV KazGeotech participated in the exhibition, in the “GEOLOGY SESSION” and in the bilateral business-meeting with Albert Rau, Vice Minister, Ministry of Investment and Development (Republic of Kazakhstan) presenting Geotech airborne geophysical technologies and Geotech-KazGeotech potential for geological exploration of Kazakhstan and the Middle Asia region.
by Gemma Barson, on June, 23, 2015
Smartphones and tablets have worked their way into almost all aspects of our lives, including work. While there has been an abundance of business related apps for some time now, it has taken a while for developers to set their sights on more niche areas. It wasn’t so long ago, for example, that the idea of carrying out field work or surveys accurately using a mobile device was laughable. Nowadays however, there are a number of advantages to using such devices in the field, from simply checking out the journals, to using high quality precision software. The fact that a tablet is considerably more transportable than a heavy piece of equipment is perhaps the most obvious advantage, but there are a number of others as well.
Cost and Practicality
Mobile devices and their potential, especially in the world of geophysics, have been a hot topic for some years now. The oil and gas sector was especially quick on the uptake of any mobile innovations, mainly due to the reliance on mobile technology that had already made itself indispensable to the more data focused areas of the industry. The main stalling point for more field focused areas of geophysics was the fact that many geophysicists were reluctant to engage with app programming. As the use of both cloud based computing and storage and mobile devices has proliferated, as well as the fact that mobile devices are now much more powerful, more apps focused on practical geophysical applications are appearing. This is mainly due to the fact that apps themselves are much easier and cheaper to program than when they first appeared. Now, geoscientists are able to apply their knowledge of their field directly into app form, and solve problems or streamline processes in such a way that makes a tablet a valuable piece of field kit. Another advantage to the proliferation of these specialist apps is they are highly customisable – a feature that is often missing from more unwieldy field equipment. Mobile techs and specialist apps have, as a result, opened up a whole new range of possibilities for all levels of projects for geoscientists across the world. One slight drawback of course, is that tablets can be quite fragile, and are not generally designed to withstand wilderness locations. This can be offset by the fact that cloud computing offers a secure, always accessible storage option for key data. Scientists can also take the simple step of making sure their equipment is protected from damage in case of accident.
In recent years, a number of geoscience solution providers have also turned their attention to app development, either as standalone products or as companion software to other devices or software. The AGI SuperSting is one such example, which allows a number of remote functions to be performed on the SuperSting equipment, as well as a number of functions. The CSEMoMatic is another example of full service modelling software in app form, which could prove to be extremely useful on a field trip. Mobile database apps in particular are especially popular, and are effectively closing the gap between the expensive kit that is exclusively available to scientists, and everyday technology.
Utah University showcased the value and practicality of a geophysics focused app with the High Density Large Woody Debris app which was used for a large scale stream restoration project. As apps get even cheaper and easier to make, increasingly complex science can slowly make its way into the public domain. With the right tools for example (in app form), there is nothing to stop community and citizen science projects from undertaking experiments projects that would previously have required professional level equipment and software.
For the professional world, the use of database apps to streamline field readings, and data flow in general, is likely to have some far reaching, positive benefits to not only geophysics, but the sciences in general. Coupled with cloud computing, increasingly powerful tablets and mobile devices, as well as more wide reaching, faster Wi-Fi access, it might not be long before the tablet and a number of trusty apps are the most important part of any geophysics expedition or field study. Geophysics may not be alone in these developments either, as more and more scientific fields are embracing the power of the app.
Abitibi Geophysics together with GEM Systems announced about creation of the partnership AeroVision™ for using UAV magnetic system which explores two potassium sensors. The system is going to be available since June, 1. Sampling interval is promised 2 meters and resolution of .0001 nT, absolute accuracy +- 0.05 nT. Laser-altimeter, GPS and auto-pilot are included.
The UAV mag surveys cost is going to be over 50% of the present ground geophysics pricing.
Galym Nurjanov (a head of JSC “National exploration company “Kazgeology”) has held a press conference at RSU “Central Communications Service for the President of the Republic of Kazakhstan” and reported about success in investments attraction in the mineral exploration sector of Kazakhstan economy.
Over the past two years the four major foreign investors came to Kazakhstan – the Australian-British concern “Rio Tinto”, a South Korean corporation “KORES”, the Australian company “Iluka Resources” and the German investment fund “ULMUS FUND”. These companies are willing to invest into the mineral exploration sector over $ 5.5 billion tenge. Airborne geophysical surveys are going to be started soon in connection with Rio Tinto and Iluka Resources projects. The advanced airborne geophysical technologies including VTEM and ZTEM which are used right now in Kazakhstan, have been brought by Canadian company Geotech Ltd.
“INTEGRATING NEW TECHNOLOGY WITH HISTORICAL DATA, GEOLOGICAL INTUITION AND A LITTLE LUCK, COMPANIES ARE FINDING SUCCESS WHERE OTHERS HAVE NOT”
E&MJ News published an article by Steve Fiscor where some factors of new mineral deposits discoveries have been outlined – these factors include applying modern geophysical technologies. The author provides some examples – airborne EM (VTEM, ZTEM), airborne gravity gradiometer, and airborne radiometric surveys which played key role in discoveries of mineral deposits.
“All of the discoveries were in the zone of other major discoveries, but most of them had been overlooked for one reason or another. The motivation could only be attributed to a geologically motivated hunch. New technology in the form of deep-penetrating airborne surveys allowed ground-based geophysical surveys to target undiscovered anomalies. Combining the new information with what they knew historically, exploration geologists were able to improve the drilling programs to quickly determine a resource.”
The next discoveries made with airborne geophysical technologies:
Albany Ultra-pure Graphite – VTEM survey
The Balboa Discovery at Cobre Panama – ZTEM survey
Kennady North Kimberlite Discoveries – airborne gravity gradiometer survey
PLS High Grade, High Techand Contrarian – airborne radiometric survey
Karl Kwan (Geotech LTD) presented at Canadian Exploration Geophysical Society meeting (8 April 2014) methodology and examples of using Neural Network Targeting and Classification at mineral exploration.
“Geophysical survey contractors routinely offer multi-parameter data to clients. For example, a helicopter-borne survey may acquire Time-domain electromagnetic (TDEM), magnetic gradiometer and even gamma-ray spectrometer data (i.e., VTEMplus, Geotech LTD). Exploration geophysicists can certainly take advantage some of the readily available multi-disciplinary (geology, geophysics and remote sensing) and multi-parameter (potential field, EM, gamma-ray spectrometry, and others) datasets for mineral exploration. However, the integration and interpretation of these datasets can be time-consuming and even challenging, especially for large-scale datasets covering large areas with diverse geological conditions. The Supervised Neural Network (NN) Targeting and Classification technique for mineral exploration described and demonstrated by Reford, Lipton and Ugalde, 2004, “Predictive Ore Deposit Targeting Using Neural Network Analysis” (http://www.pgw.on.ca/downloads.html), can be a useful and promising tool for the analysis of multi-disciplinary and multi-parameter data.
In this presentation, the properties or responses of the two feed-forward multilayer Neural Networks, Levenberg-Marquardt (NN with LM training) and Fast Classification (FCNN), as implemented in the current version by PGW, are studied in detail. The supervised NN simulations are performed on specially constructed synthetic data. Intended as a tutorial and the NNs treated as black boxes, the objectives of the exercise are twofold, to demonstrate the targeting as well as classification capabilities of the Neural Networks, and at the same time to show one of the known limitations and to suggest a way to get around it. The utility of the NN tool is demonstrated again with real cases from the Republic of Niger.”
Geosoft is delighted to host the online portion of the Canadian Exploration Geophysical Society meeting with keynote speaker Karl Kwan, Geotech LTD.
“The recent rush to find graphite and vanadium deposits to satisfy potential demand in green energy applications is reigniting airborne electromagnetic (EM) methods as highly effective exploration tools.”
ANCHORAGE, Alaska — A tool used by mining companies to find mineral ores has been adapted to map frozen soils below the ground in Alaska and could be used to track the effects of global warming, according to the U.S. Geological Survey.
The agency announced Monday that an airborne survey conducted in Alaska’s Yukon River drainage collected unprecedented images of the presence and absence of permafrost down to 328 feet. The study used an electromagnetic survey tool flown beneath a helicopter.
“We really think we’ve got the story nailed down from these data,” research geophysicist Burke Minsley said by phone from the Crustal Geophysics and Geochemistry Science Center in Denver.
Minsley is lead author of the study published Friday in the journal Geophysical Research Letters (http://www.agu.org/pubs/crossref/2012/2011GL050079.shtml).
Mapping permafrost extents has been done by satellite, Minsley said.
“It’s hard to get any information at depth, and that’s what’s unique here,” he said.
Permafrost is below about 24 percent of the land area in North America. The research will be important for climate scientists looking at the thawing of permafrost as a greenhouse gas contributor, studying ecology in lake systems, or looking at the effects of thawing ground on river chemistry, Minsley said. Thawing also will bring important impacts for northern infrastructure such as buildings and roads.
The Yukon River begins in Yukon Territory, Canada, and spans Alaska from east to west.
The research team surveyed more than 116 square miles of the Yukon Flats in an area centered 140 miles northeast of Fairbanks. The area was picked in part because it’s between continuous permafrost to the north and discontinuous permafrost to the south, according to the agency.
Electromagnetic surveys have been used in mining for years, Minsley said. Scientists recently have used it to define the geometry of aquifers in Nebraska.
“What’s new about it is that it’s being used for more discrimination of more subtle features related to things like groundwater and permafrost,” Minsley said.
The tool is torpedo-shaped and about 33 feet long. In front are coils oscillating at different frequencies, Minsley said. Towed by a helicopter and flown just under 100 feet off the ground, the tool sends electromagnetic pulses into the ground and determines what’s below by measuring how well the pulse is conducted. The ground itself has conductors and resistors. Permafrost is not as conductive as solid ground.
“It induces currents in the ground. Those currents induct a signal, a magnetic field, that’s picked up by another set of coils that’s in the back of that thing that we’re towing under the helicopter,” Minsley said.
The tool collected data that showed a lack of permafrost below the Yukon River and other water bodies that don’t completely freeze in the harsh interior Alaska winter.
“That’s consistent with a lot of conceptual models that people have developed, but they haven’t really had the solid measurements that we have to see that,” Minsley said.
The mapping also showed “thermal relics” where the Yukon River had been centuries ago. As the river migrated to a new location, ground slowly refroze. The farther away from the new location, the more it had frozen in a downward slope. Minsley said it was the biggest surprise of the study.
“It was not something we expected to capture in this data set, to actually see that thermal legacy over a thousand-year history. That’s pretty rare for this kind of data,” he said.
The tool collected data over only one week in June 2010. Minsley said he spent four to five months analyzing and processing data to make images, and the research team spent many more hours interpreting the results.
Drilling boreholes to acquire the same information would have taken a much greater effort, he said.
Shell and HP have announced a breakthrough in the capability of their jointly developed inertial sensing technology to shoot and record seismic data at much higher sensitivity and at ultra-low frequencies.
The new onshore wireless seismic acquisition system is designed to provide a clearer understanding of the earth’s subsurface, thus increasing prospects for discovering greater quantities of oil and gas to meet the world’s increasing energy needs.
The sensing technology has now been demonstrated to have a noise floor – a measure of the smallest detectable acceleration over a range of frequencies – of 10 nano-g per square root Hertz (ng/rtHz), which is equal to the noise created by the earth’s ocean waves at the quietest locations on earth as defined by the Peterson low noise model. The tests were conducted in the seismic testing vault at the US Geological Survey’s (USGS) Albuquerque Seismological Laboratory facility in New Mexico.
The seismic system uses the breadth of HP’s technology development capabilities as well as Shell’s advanced geophysical expertise in seismic data acquisition systems and operations. As such, this collaboration builds on the core strengths of each company to advance technology in this field.
The system will be delivered by HP Enterprise Services and the company’s IPG. It is based in part on the high-performance sensing technology originally co-developed by HP Labs – the company’s central research arm – along with IPG and Shell research in seismic network design.
Fig. 1. The survey will be flown using BlueQube technology.
This technique has allowed us to attribute anomalies in physical properties, with respect to the ‘normal’ host properties, with an expected alteration type. The technique is particularly applicable in the Cobar region because there is limited physical property contrast between host units and alteration is the predominant cause of geophysical anomalies. The technique is also applicable in regions that are under significant cover. As with any geophysical technique, the exact results will depend on the property contrast from host to altered product. A strong host-to-host property contrast will require a more detailed geological model to obtain the best results, but mapping of gross alteration trends should still be possible with only a very simple inversion reference model.