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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 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...

Phantom Mountains under the Antarctic Ice




The surface of the Greenland ice sheet.
Photo courtesy of Michael Studinger,
Lamont-Doherty Earth Observatory of Columbia University.

An international project probes the world's last great unexplored mountain range. Catch is, it lies under three kilometres of ice.

By Graham Chandler

Fifty years ago, a team of Soviet scientists was conducting a seismic survey as they headed for what is known as the Pole of Inaccessibility, the point in the Antarctic furthest from any coast, when they made a remarkable discovery
- a massive subglacial mountain range that has left earth scientists scratching their heads. According to received theory, it shouldn't be there. Hypotheses had predicted there would be nothing but a vast and somewhat featureless plain much like Canada's interior. 

Land gravity measurement with differential GPS positioning.
Fausto Ferraccioli, Airborne Geophysics Group
Leader of the British Antarctic Survey

"We don't have a clue as to why these mountains should be there at all in the middle of a continent," says Fausto Ferraccioli, Airborne Geophysics Group Leader of the British Antarctic Survey. "It's really a mystery to have a very high mountain range in an old Precambrian region. Typically mountain ranges are created by collisional processes or by extensional processes. But these mountains are really very, very high, and the last collision that happened in East Antarctica was about 500 million years ago, so these mountains should have been basically eroded."

Left largely unexplored for the past five decades except for confirmation by US aerial radar survey in the 1970s, the Gamburtsev Mountains are now front and centre of the international AGAP (Antarctica's Gamburtsev Province) Project, and the British Antarctic Survey is one of the participants. "This is a major flagship project of the International Polar Year," says Ferraccioli, "and it will involve six different countries – the US, Germany, China, the UK, Australia and Japan."

The initiative is led by the Lamont-Doherty Earth Observatory of Columbia University and is not only multinational but also multidisciplinary, "including aerogeophysics, traverse programs, and passive seismic instrumentation complimented by future ice core and bedrock drilling," says Michael Studinger, Doherty Research Scientist at the Observatory and co-chief scientist. The crews expect to be in the field early November 2008 to mid-January 2009.

Land gravity measurement with differential GPS positioning. Project overview for the exploration of the Subglacial Gamburstev Mountains. Courtesy of British Antarctic Survey.
(Click to enlarge
)

Spurred by the mysterious mountains, four basic questions have arisen that underpin this international team's work. How does topography influence initiation and development of continental ice sheets? How do major mountain massifs form within intraplate settings with no straightforward plate tectonic mechanism? How do tectonic processes control the formation, distribution, and stability of subglacial lakes? (There are lakes under this ice too) Where is the oldest climate record in the Antarctic ice sheet?

To acquire data for some answers, over the past two years the team has been preparing the complex logistics and developing an airborne geophysical system for the project: ice-penetrating radar, LiDAR (Light Detection and Ranging), gravity and magnetics.

It's more than scientific curiosity about the earth's formation processes. Answering these questions will help our understanding of climate change. "One of the fundamental questions in Antarctic science is when, where and how the Antarctic ice sheet formed," says Studinger. "Preliminary ice-sheet modeling suggests the Gamburtsev Subglacial Mountains are the likely location for initiation of the East Antarctic ice sheet, and therefore could be a key factor in understanding the onset of glaciation in the Paleogene 35 million years ago."

He explains that in order to understand the evolution of the Antarctic ice sheet over such long time scales we need to understand the relationship among Antarctic geodynamic processes, ice-sheet dynamics, and global environmental change. "For example mountain uplift can influence climate and thus ice-sheet dynamics," he explains. "In turn, climate change can lead to increased erosion rates and accelerated mountain uplift." It has been suggested that during warmer periods, this terrain was drained first by ice streams and then, nearer the coast, by rivers from which thick sediments accumulated. "We have a conceptual understanding of these processes but it is essential to move towards quantitative models." He adds that a lack of first-order data sets for most of the continent has so far precluded formation of such a model.

Land gravity measurement with differential GPS positioning. Remote field camp and Twin Otter aircraft,
similar to what will be set up at the AGAP north site.
Copyright British Antarctic Survey

It's expected that data gathered during the AGAP project will go a long way towards this end. "We want to find out what these gigantic mountains are and where they come from; because no-one really knows how they formed," says Studinger. "There is really no straightforward explanation as to how you get such high mountains in the interior of a continent." He says the new data will enable us to "uncover" this phantom mountain range, which is larger than the Alps.

Ferraccioli says there are several scenarios, e.g. "that these mountains are actually quite recent, for example they could be related to a hot spot, which is in essence a hot mantle similar to what we've seen in Iceland. This would basically radically change our view of East Antarctica as a sort of stable, Precambrian continent."

Searching for the oldest ice on the planet also provides critical input to knowledge of past climate change, helping our understanding of today's global warming. Ice cores contain valuable preserved records of past atmospheric composition, volcanic eruptions and other environmental information. "In Antarctica, we have drilled at a series of locations and retrieved ice as old as about 900,000 years," says Ferraccioli, which provides a record that far back. "In this particular region, we believe that there may be ice that is over 1.2 million years old and so this would provide us with an unprecedented record of climate change in the past."

Land gravity measurement with differential GPS positioning. Flight testing in Kangerlussuag, Greenland.
From left to right: Jason Preston (Kenn Borek Air Ltd.), Michael Studinger (Lamont-Doherty Earth Observatory of Columbia University), Nick Frearson (Lamont-Doherty Earth Observatory of Columbia University), Adrienne Block (Lamont-Doherty Earth Observatory of Columbia University), Travis Goetzinger (Kenn Borek Air Ltd.), Colin Anderson (Kenn Borek Air Ltd.). Photo courtesy of Michael Studinger, Lamont-Doherty Earth Observatory of Columbia University.

Although the airborne magnetic and gravimetric survey will be able to hint at mineral composition, none of the AGAP research is aimed at mineral exploitation. Copper, lead, zinc, gold and silver have been found on the Antarctic peninsula and oil and gas is most likely present in its sedimentary basins, but by international agreement exploitation has been banned. The 1959 Antarctic Treaty dedicated the continent to peaceful use, established international exchange of scientific data and outlawed new territorial claims; and in 1991 the signatories agreed that "any activity relating to mineral resources other than scientific research" is prohibited. The AGAP project fits: a 1998 follow-on preserved the continent as an archive of the world's climatic past and a barometer of the planet's future.

Part of the reason exploration of this mysterious subglacial topography has been limited is simply logistics. The Antarctic is a forbidding place. Ice covers 98 percent of its land and in winter extends to an area larger than the continent itself. Thirty million cubic kilometres of ice depresses its bedrock by 600 metres and tilts the icesheets towards the centre. It constitutes 72 percent of the world's fresh water yet precipitation is about the same as the driest parts of the Sahara. The record low is –89.2 degrees C. And distances are daunting. "The survey region is about 1000 kilometers away from the South Pole and equally about 1000 kilometers away from Davis and Zhong Shan, which are respectively the Australian and Chinese bases on the other side of Antarctica," says Ferraccioli. "So it's really in the middle of nowhere. It's the highest spot on the East Antarctic Ice Sheet. It's over 4,000 meters high." He compares the challenge with going to Mars. "On the surface, all you would see is a white ice sheet," he says.

The thickness of that ice will be probed by the airborne radar, which can image ice over four kilometres thick. "We can understand the layers of  ice," says Ferraccioli, "which gives you an idea of basically [how] ice ages. The layers can be correlated with future drill sites, which the Chinese are interested in." Eventually a more permanent base for drilling will permit an expensive but revealing entry into the oldest levels of ice and the rock below the ice. "If in five to ten years' time, the Chinese do attempt to drill there, it will only be to sample the rock of this mountain range," says Ferraccioli. "Not for mineral exploitation but really just to try and verify the geophysical interpretations." Even just one drilling effort would help ground-truthing in a large way but still be far from providing the entire picture of the mountain range, he adds.

Land gravity measurement with differential GPS positioning.
US seismic team.
Copyright Douglas A Wiens, Washington University.

The radar will reveal some details on subglacial lakes too, which may be affecting the dynamics of the ice sheet. The glacial lakes are a major objective of the project. "We will be surveying some large subglacial lakes with the aerogeophysical survey," says Robin Bell, Director, ADVANCE Program at Columbia's Earth Observatory. Exploration by remote submersible is on the horizon too. "There are plans to enter both subglacial Lake Vostok and Lake Ellesmere in the next few years but no submersible this season."

The aeromagnetics will provide indications of subglacial geology, by assisting with mapping of possible volcanic regions, major tectonic boundaries and potentially thermal anomalies. "Then we use gravity," says Ferraccioli, "which will give us indications of possible sedimentary basins, the thickness of the crust and will also give us indication of possible anomalies such as density in the upper mantle." A hot spot he says would indicate a low density mantle.

Data gathered will be varied and of a large volume so both standard and specialized software is needed to process them. For example, each four-hour flight will generate 500 gigabytes of data. "It's a large data set with a variety of data streams that differ substantially in size and structure," says Studinger. "This makes the use of multiple software packages necessary." Some of these he says are developed in house using Matlab, for organizing and structuring the data sets and for initial quality control and archiving. 

The gravimeter for the survey will be provided and operated by Sander Geophysics Ltd. who designs and uses its own company software for quality control, data reduction, viewing, and map production. "After initial quality control and archiving of the airborne and ground magnetic data with our Matlab tools we use Geosoft's Oasis montaj for further processing, data analysis and map production," says Studinger. Oasis montaj allows efficient importing, viewing, processing and sharing of diverse earth science datasets and images. "We use the basic airborne geophysics package and several extensions for modeling, filtering, and source depth estimates that enable us to perform state of the art analysis of our airborne magnetic data," he says.

Land gravity measurement with differential GPS positioning.
British Antarctic Survey Twin Otter aircraft
equipped with ice penetrating radar survey gear.
Copyright British Antarctic Survey.

Ferraccioli says potential field data, such as magnetic and gravity, is obviously non-unique, "so we're also going to fit our interpretations with seismology – which in particular will give us indications of the crustal thickness and again possible anomalies in the upper mantle." The potential field data will be processed using Geosoft. "We will be doing gravity and magnetic modeling using GM-SYS." This tool enables design of 3-D models depicting subsurface structures by for example stacking montaj topography grids. 

What will be the prize at the end of the process? "The product will be a new map of the sub-glacial topography of the Gamburtsev sub-glacial mountains province," says Ferraccioli. "We will have new maps of aeromagnetic anomalies over this area. New maps of Free-Air gravity, Bouguer gravity and isostatic gravity maps for the region. Then we will also be producing new crustal models to try and define the uplift of the Gamburstev sub-glacial mountains."
 
But these two organizations won't be taking all the credit. "Projects of this size are only possible through collaboration between many scientists and organizations from countries around the world," says Studinger. "We see the AGAP project as a model for future science projects in Antarctica."