By Lewis Ball, CSIRO
The future looks very bright for Australian radio astronomy but it was somewhat clouded earlier this year when CSIRO’s radio astronomy program took a dramatic hit in the Australian federal budget.
CSIRO has cut its funding for radio astronomy by 15%, down A$3.5 million to A$17 million for the 2014-15 financial year. The result will be a reduction of about 30 staff from the plan of just three months ago.
The cuts will impact most heavily on CSIRO’s in-house astronomy research, on the operation of the Parkes radio telescope – instantly recognisable from the movie The Dish – on the less well known but tremendously productive Australia Telescope Compact Array near Narrabri and on the Mopra Telescope near Coonabarabran, all in New South Wales.
About two-thirds of ATNF’s staffing reduction will be effected through not filling planned new roles, most prominent of which was to be a CSIRO “SKA Chief Scientist”. A third of the reduction will be through involuntary redundancies. Eight staff across sites in Sydney, Parkes, Narrabri and Geraldton have already been informed that their roles are expected to cease.
The speed of implementation of such a substantial funding reduction forces swift action. This has unsettled staff and the broader astronomy community, but it hasn’t changed the broad direction of CSIRO’s astronomy program.
World leaders in radio astronomy
Australian scientists and engineers are world leaders in radio astronomy, both in understanding our universe and in developing some of the most innovative technologies used to gain that understanding, and have been for 50 years.
CSIRO’s Australia Telescope National Facility (ATNF) has been integral to the discovery of the first double pulsar system (a long-sought holy grail of astronomy), the identification of a previously unknown arm of our own galaxy, the Milky Way, and the invention of Wi-Fi now so embedded in everyday communications.
For the past decade CSIRO has been steadily changing the way it operates its radio astronomy facilities. CSIRO’s highest priority is the pursuit of science enabled by the development of an innovative new technology that provides an unprecedented wide field of view.
This uses “Phased Array Feeds” (PAFs) as multi-pixel radio cameras at the focus of dishes. PAFs are being deployed in the Australian SKA Pathfinder (ASKAP), in Western Australia, which will be the fastest radio telescope in the world for surveying the sky.
ASKAP is in the early stages of commissioning. It is just now starting to demonstrate the new capabilities obtainable with a PAF-equipped array.
ASKAP is an outstanding telescope in its own right but is also a pathfinder to the huge Square Kilometre Array (SKA). This enormous project will build the world’s biggest astronomy observatory in Australia and southern Africa. It’s also the most expensive at a cost of around A$2.5 billion.
Cutbacks at The Dish
To resource these exciting developments, CSIRO has been reducing costs and staffing at its existing facilities, including the venerable Parkes Dish. This is a painful but necessary process. The most recent funding cuts will result in more pain.
Astronomers will no longer have the option of travelling to the Compact Array to operate the telescope to collect their data. They can run the telescope from CSIRO’s operations centre in Sydney, or from their own university, or from anywhere in the world via an internet connection.
Astronomers who use the Parkes telescope have been doing this for the past year after a very successful program to make the 50-year-old dish remotely operable. That is pretty amazing for a machine built before the advent of modern computers.
For many decades Parkes staff have swapped detector systems or “radio receivers” in and out of the focus cabin, the box at the tip of the tripod that sits about 64 metres off the ground. Each receiver operates at different wavelengths and offers quite different types of science.
It seems likely that CSIRO will offer just two Parkes receivers for at least the next six to 12 months, since it will no longer have the staff needed to swap receivers. Similar reductions in the capability of the Compact Array will also be needed to fit within the budget.
While the current changes are painful, the future is incredibly exciting. The direction of Australia’s astronomy is described in the Decadal Plan for Australian Astronomy for 2006–2015. It identifies participation in the SKA and access to the world’s largest optical telescopes as the two highest priorities for Australian astronomy.
We are making progress on both fronts, despite some significant challenges. The process to develop the plan for the next decade is well in hand under the stewardship of the National Committee for Astronomy.
Phased arrays are also at the heart of the Murchison Widefield Array (MWA), another innovative SKA precursor that has been in operation for a little over a year.
ASKAP and the MWA are located in the Murchison region of Western Australia, chosen because it has a tremendously low level of human activity and so astonishingly little background radio noise.
This radio quietness is the equivalent of the dark skies so important for optical astronomers. Less noise means astronomers are better able to detect and study the incredibly weak radio signals from the most distant parts of the universe.
This freedom from radio interference is a unique resource available only in remote parts of Australia and is essential for ASKAP, MWA and much of the science targeted by the SKA.
The wide fields of view of ASKAP and the MWA enable unprecedented studies of the entire radio sky. Astronomers will measure the radio emission of millions of galaxies and complete massive surveys that for the first time will connect radio astronomy to the more mature field of optical astronomy.
Mapping the sky with EMU and WALLABY
Both will survey millions of galaxies and together they will trace the formation and evolution of stars, galaxies and massive black holes to help us explore the large-scale structure of the universe.
The MWA is already producing great science targeted at the detection of intergalactic hydrogen gas during what’s known as the “epoch of reionisation” when the first stars in the universe began to shine.
With the SKA we aim to understand what the mysterious dark matter and dark energy are. We may also provide another spin-off such as the Wi-Fi technology, which came from CSIRO efforts to detect the evaporating black holes predicted by Stephen Hawking.
Advances in data-mining or processing techniques driven by the astonishing data rates that will be collected by the thousands of SKA antennas deployed across the Australian and African continents might provide the most fertile ground of all, illustrating once again the long-term benefits of investing in cutting-edge science.
Lewis Ball has received funding from the Australian Research Council. CSIRO Astronomy and Space Science receives funding from a variety of government sources, and from NASA/JPL.
By Glenn Marsh, CSIRO
The current outbreak of Zaire Ebola virus in Western Africa is the largest ever recorded. More than 1800 people have been infected and nearly 1000 people have died. But while drug therapies are close to being available, they may not be ready in time for the current outbreak, even if safety trials are fast-tracked.
Several therapeutic treatments being developed by other organisations are in experimental phases of testing and show great promise in treating Ebola virus infections in animal models. These include antibodies (one of the body’s natural defence mechanisms to fight infections), RNAi molecules (that target the genetic material of the virus) and several more traditional pharmaceutical drugs.
Before being administered to people, each of these new potential therapies would require human clinical trials, starting with a phase I safety trial. In phase I, the products under investigation are administered to healthy volunteers to evaluate how safe the treatments are, including determining a safe dose range and potential side effects. These trials generally involve 20 to 80 individuals.
Phase II trials, used to determine efficacy, are complicated to carry out for rare viral diseases such as Ebola. Traditionally, in phase II trials two groups are treated, the first group receives the treatment or vaccine while the other group receives a placebo, or mock treatment. Evaluating the efficacy of these compounds will only be possible with direct testing during an outbreak.
But during an outbreak, and for ethical reasons, it may not be possible to administer a placebo to one group of people while treating others with a potentially life-saving therapy.
ZMapp is a mix of three antibodies, all directed to the Ebola virus glycoprotein (GP), which block attachment and entry to cells, the first step of the virus infection cycle.
ZMapp is produced in a Nicotiana plant, related to tobacco, and is being developed as a treatment for Ebola virus infection by Mapp Biopharmaceutical Inc. along with many other partners. These antibodies are “humanised” monoclonal antibodies, stopping the human immune system from recognising them as foreign.
ZMapp was the experimental therapy administered to the two American medical aid workers infected with the Ebola virus. The medics were working in Liberia, trying to contain this outbreak.
This experimental cocktail of antibodies builds on the success of similar antibody therapies, which have protected macaques from a lethal dose of Ebola virus when administered 24 hours after infection. Media reports indicate the two health-care workers have shown signs of improvement.
ZMapp is not the only experimental therapy to show promise in animal studies in preventing lethal disease for Ebola virus. Tekmira Pharmaceuticals Corporation are currently undergoing a phase I clinical trial of TKM-Ebola, a RNAi therapeutic targeted towards Zaire Ebola virus. This therapy was demonstrated to give 100% protection in macaques from an otherwise lethal challenge of Zaire Ebola virus.
In March 2014, the US regulator, the Food and Drug Administration (FDA), fast tracked TKM-Ebola as a drug for an unmet medical need. However, the phase I clinical trial was recently suspended due to safety concerns, with individuals receiving higher doses developing an inflammatory, flu-like response to treatment.
Due to the relative risk from the disease versus the treatment, in the last week, the FDA has eased the restrictions on TKM-Ebola. This may allow for TKM-Ebola to be used in infected patients.
Developed by BioCryst Pharmaceuticals Inc., BCX4430 is a broad-spectrum antiviral that inhibits different many viruses. BCX4430 has been demonstrated to protect rodents from Ebola virus and macaques from Marburg virus, a closely related virus.
Favipiravir, which is in late-stage clinical development for the treatment of influenza, has reduced the severity of disease and risk of death in a mouse model of disease.
So, should these therapies be used now to treat infected people, bypassing clinical safety trials?
Giving treatments, which are unlicensed and untested in humans, is an ethical issue. Likewise, not administering a potentially life-saving therapy is also problematic. These decisions would have been carefully considered prior to the treatment of the two American aid workers with the unlicensed ZMapp antibody.
In recognition of the difficult ethical issues that arise in this debate, the World Health Organization is meeting to discuss the current outbreak and relevant issues. Much of the debate centres on a popular belief: if an individual is likely to die and an experimental therapy has a reasonable chance to prevent death, then it should be given.
But there are other issues to consider: what if the experimental therapeutic makes the disease worse? And who decides who to treat when only small numbers of doses are available?
Additionally, for many of these experimental therapies, only a small number of doses are currently available to be used for treatment. Many of these therapies would require weeks, if not months, to produce sufficient doses for large scale use.
Although there is currently no end in sight for this outbreak, research and clinical trials of these new therapies for Ebola virus needs to continue. That way, when the next Ebola virus outbreak occurs, there will be licensed options available and the discussion about whether unlicensed drugs should be used will be negated.
Glenn Marsh receives funding from NHMRC.
One of the most common questions Australians ask about coal seam gas is whether the gas wells leak – and if so, how much?
In the first Australian study of its kind, new CSIRO research now gives an indication of how much those “fugitive emissions” might be, and how we can start to reduce them.
Commissioned by the federal Department of the Environment and now published on its website, the pilot study measured emissions around 43 coal seam gas production wells – six in New South Wales and 37 in Queensland – out of the more than 5000 wells currently operating around Australia. The results reveal that:
- nearly all of the 43 wells tested showed some fugitive emissions;
- the emissions rates were very low (in most cases less than 3 grams of methane per minute – equivalent to methane emissions from around 30 cows);
- in many cases, those emissions could be reduced or even stopped entirely; and
- the average measured levels from the Australian wells were 20 times lower than reported in a study of fugitive emissions from US unconventional gas sites, published last year in the leading international journal Proceedings of the National Academy of Sciences
In Australia, fugitive emissions from coal mining, oil and gas production account for about 8% of Australia’s greenhouse gas emissions.
Although those fugitive emissions are estimated and reported under the National Greenhouse and Energy Reporting Act, there has often been a high degree of uncertainty associated with these estimates in Australia – particularly from coal seam gas production.
That’s why this new research is important, as it offers a first indication of fugitive emissions from coal seam gas under Australian conditions.
The report’s results
Our new report, Field Measurements of Fugitive Emissions from Equipment and Well Casings in Australian Coal Seam Gas Production Facilities, shows that of the 43 wells studied, three had no detectable leaks.
Of the rest, 37 wells emitted less than 3 grams of methane per minute, and 19 of those showed very low emission of less than 0.5 grams of methane per minute.
However, at a few wells (6 of the 43) much higher emissions rates were detected, with one well registering emissions 15 times higher than the study average. That was found to be mainly due to methane discharging from a vent on a water line.
On closer scrutiny, some of the leaks were due to faulty seals on equipment and pumps, which could be easily fixed, while other emissions were associated with exhaust from gas-fuelled engines used to power water pumps that are not regarded as “fugitive” emissions.
We tested for emissions using a four-wheel-drive fitted with a methane analyser. The car made several passes downwind from the well to measure total emissions emanating from the site.
To ensure that other potential methane sources, such as cattle, were not inadvertently included, similar measurements were made upwind of each test site. We also took a series of measurements at each well to locate sources and measure emission rates.
Why worry about fugitive emissions?
Fugitive emissions occur when methane escapes from production facilities, wells, pipes, compressors and other equipment associated with coal mining or natural gas extraction. Other human induced methane emissions occur through grazing of domestic stock, agricultural production and from landfills.
In nature, methane is released from geological sources and biological processes occurring in wetlands, swamps, rivers and dams. About 15% of human emissions of methane are derived from fossil fuels.
While burning gas for energy has lower greenhouse gas emissions compared to other fossil fuels like coal, methane has a global warming impact at least 25 times that of carbon dioxide (when measured over a 100 year period).
Even small losses of methane during gas production, processing and distribution have the potential to reduce the relative greenhouse benefit of natural gas as a fuel for electricity production.
Fugitive emissions can be costly for the coal seam gas industry because escaping gas represents a loss of a valuable commodity.
What’s next for CSG emissions research?
These new findings from 43 wells are a good start, but they are clearly only the beginning, given that represents fewer than 1% of Australia’s coal seam gas wells. More measurements are required to representatively sample the remaining 99% of wells before we can make definitive statements about methane fugitive emissions in Australia.
CSIRO scientists, through the Gas Industry Social & Environmental Research Alliance (GISERA), are undertaking further research into methane emissions in Australia including understanding the natural or background emissions of methane that come from seeps in the ground in Queensland’s Surat Basin.
This research aims to identify background sources of methane and determine the best detection and measurement methods.
Results from measuring naturally occurring methane seepage, as well as the results of this new report and others, will add to the bigger picture of assessing the coal seam gas industry’s whole of life cycle greenhouse gas emission footprint. Most importantly, we hope they will provide more answers to Australians’ question about coal seam gas.
By Jan Bingley, general manager of business development and commercial
I learned a long time ago that “commercialisation” is a greatly misunderstood activity. Most often, it is interpreted narrowly as the process of developing IP, protecting it in the form of patents and licensing them for royalties or equity in start-ups.
It’s not surprising that commercialisation is seen this way. Many universities and publicly funded research agencies continue to measure performance by counting the number of royalty-bearing licences, number of start-ups formed and the revenue received each year from these transactions. Indeed we do it here in Australia via the National Survey of Research Commercialisation published by the federal government. The largest association for university commercialisation – the Association of University Technology Managers – measures this annually via its large commercialisation survey covering hundreds of North American Universities.
However, the comparison between CSIRO’s annual revenue and the revenue received from commercialisation transactions published at the link above, is based on misunderstandings and is misleading. About 34 per cent of CSIRO’s annual revenue, just over $400 million, is provided by our industry partners and other clients to fund specific collaborative R&D projects. The balance is provided by the federal government. CSIRO has hundreds of collaborations every year with industry – both big and small – and every one of them is all about commercialisation. Alongside our industry partners, we identify the problems that need solving, work together to solve them, and the resulting IP – in the form of know-how as well as protectable IP – rests with the industry partner. Those partners may go on to develop it further, often involving many more years and millions of dollars to reap the commercial benefits.
CSIRO sometimes secures a future financial benefit as a reward for collaborating with an industry partner, but in revenue terms this will be tiny. However, in impact, having an industry partner go on to become bigger, better and stronger is what CSIRO strives to achieve. This is why we continue to enjoy considerable government funding. We are here to assist industry for the benefit of Australia and Australians. Industry in all its forms – not just start-ups.
It is rare that CSIRO develops IP in its own right: most of our IP has been developed in collaboration with our partners and is therefore encumbered through that collaborative activity. This means that CSIRO’s patent portfolio is not littered with “Rembrandts in the attic” that some think we must be hiding. Occasionally, we see an opportunity to generate impact through licensing to start-ups and we are immensely proud of the success of these start-ups and the impact they are generating for Australia .
OUR PATENTS ARE OFTEN SCIENCE-BASED
There are numerous examples of start-ups that have benefited from licensing IP from CSIRO – BuildingIQ, Benitec, Radiata, Starpharma, Windlab, BarleyMax, Advantage Wheats, GeoSLAM, and many others. CSIRO can improve on its licensing regime to ensure we are as efficient as possible when transacting with start-ups. We are learning from this feedback and we’ve taken steps to address this, including coming up with standard licence terms. However, it is wrong to think CSIRO’s patent portfolio is the answer to generating more start-ups in Australia. Our patents are often very science-based, far away from productisation and require significant amounts of money and time before any prospect of commercial returns are possible. In short, our patents are rarely suited to a start-up model.
I’ve been approached over the years by many entrepreneurs looking for an opportunity to commercialise our IP – only very occasionally has this engagement resulted in spotting something in the portfolio suited to a start-up model. On average, we license our technology to two or three start-ups each year (a high rate in comparison to most publicly funded research agencies). CSIRO’s mission is to deliver innovative solutions for Australia’s industry, society and environment through great science – we’re about doing Science for Impact. Getting our science out of CSIRO and into the hands of businesses – big and small – that have the resources to go on and commercialise (use) the science for positive impact for their business and therefore generate positive outcomes for Australia and Australians.
We also partner extensively with established Australian SME’s so they can access CSIRO’s extensive know-how and intellectual horse-power to better their businesses – in some cases we even provide funds to those SMEs so they can access innovation to ultimately become bigger, more competitive companies. CSIRO’s SME Engagement Centre assists small to medium Australian enterprises by identifying and connecting companies to technical expertise and resources, defining technical issues, developing research projects for industry and providing guidance around access to funding for research.
If CSIRO receives small amounts of revenue in recognition of our involvement along the way, that’s great as we reinvest that into new science. But it is by no means a measure of the significant impact we seek to generate from taxpayer funds in research. The real impact of commercialisation is not the narrow discussion about royalty earnings, it’s about benefits to the economy and society. One of our best known inventions is our WLAN patent that has earned $425 million in licensing revenue, but in evaluating the success of this invention we also have to take into account the value created by the fact that our wireless technology enables over seven billion devices around the world.
Think about how much that CSIRO invention is the basis of today’s connectivity – how we each use it, every day. Now that’s impact.
This article was first published in the Australian Financial Review 22 July 2014
By Alex Wonhas, CSIRO
Can you match the following three statements with the answers just below?
- Coal seam gas is bad for the environment and we should all protest against its use.
- Genetically modified foods are a part of multinational plans to take over the world’s food supply.
- Wind farms are dangerous to human health and should be restricted.
a) Yes, everyone knows it is bad news.
b) Well, I used to think that, but now I wonder if I was being manipulated by interest groups playing upon my emotions.
c) I’m not really sure about that. I think there is more misinformation than information around.
I’m guessing if you passed these questions around at your family dinner table, you’d match different statements with different answers. This is largely because we tend to look for answers that suit our views – and often form our views based on what our “tribe” thinks.
But imagine a new technology came along – let’s call it Technology X – that could provide a source of energy for Australia, but which comes with social and environmental impacts. How would you form your opinion on it?
You might consider doing your own research, but be quickly overwhelmed by the amount of information for and against, and not know quite what to believe. At that point you might look for the opinion of somebody you trusted, or make a decision based on your intuition. In this article I encourage you to form your own opinion based on your own and independent assessment of the facts.
Our rational and emotional brains
Our intuition is a useful thing that has served us well for tens of thousands of years, keeping us from wandering out of our warm caves into the dark and dangers of the night – but it is something that has become less suited to the modern high-technology world.
We like to think we are rational beings. But when faced with uncertainty, we still have a tendency to make decisions based on emotions, before looking for information to support our decision; even sticking with that decision when data proves it is wrong.
What if we were able to put that aside and make decisions on contentious issues, such as coal seam gas, based on our own individual assessment of the data?
As with any issue, there are interest groups on all sides that would have you believe that they are the only people providing a true interpretation of the data.
Yet despite differences on interpretations, there are some common things we should be able to agree on about unconventional forms of gas, including coal seam gas and the process of hydraulic fracturing (often nicknamed fracking or fraccing). Some of these coal seam gas facts include that:
- There are clear benefits and there are clear risks.
- There are many overstated benefits and there are many over-stated risks.
- There are impacts on the economy, environment and communities, and it is not really possible to talk about one without including the others.
- Despite all the things we know, there are still some unknowns.
Putting bad science to the test
A healthy approach to any contentious issue is to treat all information as possibly coming from a self-interested point of view, until you can confirm it or not.
There are some great resources for testing the claims of dubious alternative medicines, such as Quack Watch and of the claims of major pharmaceutical companies such as Bad Science. But where do you go to test the claims being made about unconventional gas?
I’d start by saying look at the calibre of the data, rather than the source. What studies support the statements being made? Who conducted them? Where were they published? Has any independent source agreed with the claims, or disputed them? When figures are given, do they give all the information needed?
As well as giving this scrutiny to statements you’re a bit uncertain of, it’s also useful to apply it to those that appeal to you.
Deciding whether coal seam gas is good or bad is wholly dependent on the individual’s definition of the words “good” or “bad”.
It is in the interests of the industry to make you believe that coal seam gas is good for Australia, while the opposite is true for other groups. The role of scientists, and organisations such as the CSIRO, is to act as an honest broker and try to bring some clarity to the debate.
We know that coal seam gas can be used as a source of energy and that Australia has vast reserves. But we also know that its development can have environmental and socio-economic impacts on our rural communities.
CSIRO’s aim is to inform the community, government and industry about the risks and opportunities that stem from developing Australia’s unconventional gas resources.
It is a complex issue, and a divisive one. There are things we know and there are things we don’t.
So what would you like to know? Please leave your questions and comments below, and let’s start the discussion.
Alex Wonhas will be available between 3-4pm AEST today (Tuesday 22nd July) to answer your questions about coal seam gas, fracking, or other issues related to unconventional gas.
Alex Wonhas oversees a team that receives funding from the Gas Industry Social and Environmental Research Alliance (GISERA), which is a collaborative vehicle co-funded by CSIRO, Australia Pacific LNG Pty Ltd and QGC to undertake research that addresses the social and environmental impacts of Australia’s natural gas industry. The partners in GISERA have invested more than A$14 million over five years to research the environmental, social and economic impacts of the natural gas industry. GISERA projects are overseen by an independent and publicly transparent Research Advisory Committee and made publicly available after undergoing CSIRO’s peer-review process.
By David R Mole
Volcanic eruptions are as old as the planet itself. They inspire awe, curiosity and fear and demonstrate the dynamic internal activity of the Earth. However, the impact of modern volcanoes pales in comparison to those that graced our planet millions (even billions) of years ago.
These include “supervolcanoes”, volcanic eruptions a thousand times more powerful than the 1980 eruption of Mt St Helens; and large igneous provinces (LIPs), which consist of rapid outpourings of more than one million cubic kilometres of basaltic lava, such as the Siberian Traps in Russia.
In a paper published this week in the Proceedings of the National Academy of Sciences, my colleagues and I set out to find how the hottest and rarest type of volcanoes – the ancient komatiites – were formed.
Knowing how and why komatiites are concentrated in specific belts could help discover new ore deposits, potentially worth billions of dollars.
Komatiite lava flows date back around 1.8 to 3.4 billion years and formed when Earth’s mantle (the layer between the crust and the outer core) was much hotter.
They erupted at temperatures exceeding 1,600C and produced hose-like fire fountains and lava flows that travelled at more than 40km/h as bluish-white, turbulent lava rivers.
These crystallised to form some of the world’s most spectacular igneous rocks – as well as a number of giant nickel deposits, found mainly in Western Australia and Canada.
Komatiites have been studied for more than 60 years and are fundamental in developing our knowledge of the thermal and chemical evolution of the planet, but until recently we didn’t understand why they formed where they did.
So how are komatiites formed?
Komatiites are found in ancient pieces of crust, or cratons, preserved from the Archean Eon (2.5 to 3.8 billion years ago). These cratons contain greenstone belts – preserved belts of volcanic and sedimentary material that often contain deposits of precious metals.
Many cratons exist worldwide. One of the largest is Western Australia’s Yilgarn Craton, which hosts most of the gold and nickel mined in Australia. This craton has only a few specific belts that contain major komatiite flows.
Previous research shows that komatiites were formed from mantle plumes – upwelling pipes of hot material that stretch from the outer core to the base of the crust.
Around 2.7 billion years ago in a huge global event referred to as a “mantle turnover”, multiple mantle plumes formed, and one hit the base of the early Australian continent – the Yilgarn Craton, forming some of the hottest lavas ever erupted on Earth.
When plumes first hit the base of the lithosphere – the 50-250km-thick rigid outer shell of the Earth – they spread out into discs of hot material more than 1,000km in diameter.
Today there is evidence of this in places such as the huge Deccan basalts that cover much of India.
Despite this spread, komatiite belts are sparse and only found in certain areas. One of our research goals was to find out why.
Mapping the early Australian continent
We used specific isotopes of the element hafnium to determine the age of the crust that formed the granites (the material which makes up the cratons) and if it had a mantle or a crustal source.
Mapping out the isotopic compositions of the granites revealed a jigsaw pattern in the crust, and regions where the granites formed by melting pre-existing, much older crustal rocks.
It also showed younger areas where the crust was newly created from sources in the deeper mantle.
By collecting samples of Archean granites from all over the Yilgarn Craton, we were able to map the changing shape of the Archean continent through time.
When we compared the nature and shape of the continent with the location of the major komatiite events, we found a remarkable correlation. The maps showed that the major komatiite belts and their ore deposits were located at the edge of the older continental regions.
This is due to the shape at the base of the ancient Australian continent. As the plume rises, it impacts the older, thick lithosphere first.
As a result the plume cannot generate much magma so it flows upwards along the base of the lithosphere into the shallower, younger areas. Here huge volumes of magma are generated at the boundary between the old, thick and young, thin areas of the lithosphere, so komatiites and their nickel deposits are located at the margins of Earth’s early continents.
Some research questions remain. The origin of the continents imaged in our study and the tectonic system that formed them is still unknown.
What our work shows is that continent growth significantly affects the location, style and type of later volcanism, as well as the location of major ore deposit areas.
We hope that this work will help unravel the volcanic history of other ancient geological terranes, as well as aid in the search for mineral deposits in relatively unexplored cratons such as those in West Africa and central Asia.
This project was funded by Australian Research Council (ARC) Linkage Grants LP0776780 and LP100100647 with BHP Billiton Nickel West, Norilsk Nickel, St Barbara, and the Geological Survey of Western Australia (GSWA). The Lu-Hf analytical data were obtained using instrumentation funded by Department of Education Science and Training (DEST) Systemic Infrastructure grants, ARC Linkage Infrastructure, Equipment and Facilities (LIEF), National Collaborative Research Infrastructure Strategy (NCRIS), industry partners, and Macquarie University. The U-Pb zircon geochronology was performed on the sensitive high resolution ion microprobes at the John de Laeter Centre of Mass Spectrometry (Curtin University).
By Lisa Harvey-Smith, CSIRO
The first images from Australia’s Square Kilometre Array Pathfinder (ASKAP) telescope have given scientists a sneak peek at the potential images to come from the much larger Square Kilometre Array (SKA) telescope currently being developed.
ASKAP comprises a cluster of 36 large radio dishes that work together with a powerful supercomputer to form (in effect) a single composite radio telescope 6km across.
What makes ASKAP truly special is the wide-angle “radio cameras”, known as phased array feeds, which can take up to 36 images of the sky simultaneously and stitch them together to generate a panoramic image.
Why panoramic vision?
Traditional radio telescope arrays such as the Australia Telescope Compact Array near Narrabri, NSW, are powerful probes of deep-space objects. But their limited field of view (approximately equivalent to the full moon) means that undertaking major research projects such as studying the structure of the Milky Way, or carrying out a census of millions of galaxies, is slow, painstaking work that can take many years to realise.
The special wide-angle radio receivers on ASKAP will increase the telescope’s field of vision 30 times, allowing astronomers to build up an encyclopedic knowledge of the sky.
This technological leap will enable us to study many astrophysical phenomena that are currently out of reach, including the evolution of galaxies and cosmic magnetism over billions of years.
For the past 12 months a team of CSIRO astronomers has been testing these novel radio cameras fitted on a test array of six antennas.
The first task for the team was to test the ability of the cameras to image wide fields-of-view and thus demonstrate ASKAP’s main competitive advantage. The results were impressive!
One of the first test images from the ASKAP test array is seen above. The hundreds of star-like points are actually galaxies, each containing billions of stars, seen in radio waves. Using CSIRO’s new radio cameras, nine overlapping images were taken simultaneously and stitched together.
The resulting image covers an area of sky more than five times greater than is normally visible with a radio telescope. The information contained in such images will help us to rapidly build up a picture of the evolution of galaxies over several billion years.
Where next for ASKAP to look
On the back of this success, the commissioning team turned the telescope to the Sculptor or “silver coin” galaxy to test its ability to study deep-space objects.
Sculptor is a spiral galaxy like our own Milky Way, but appears elongated as it is seen almost edge-on from earth.
This image (above) shows the radio waves emitted by hydrogen gas that is swirling in an almost circular motion around the galaxy as it rotates.
The red side of the galaxy is moving away from us and the blue side is moving towards us. The speed of rotation tells us the galaxy’s mass.
The team has also tested the ability of the telescope to “weigh” the gas in very distant galaxies. The image (below) shows a grouping of overlapping galaxies called a gravitational lens.
Seven billion years ago, radio waves from a distant galaxy were absorbed by a foreground galaxy in this group. That signal was processed by ASKAP to form the spectrum (top right in the above image).
Although not visually pretty, this type of observation has enormous scientific value, allowing astronomers to understand how quickly galaxies use up their star-forming fuel.
The latest demonstration with the ASKAP test array is a movie (below) of layers through a cloud of gas in our Milky Way.
This series of images – similar to an MRI scan imaging slices through the human body – demonstrates the ability of the telescope to measure the intricate motions of the spiral arms of the Milky Way and other galaxies.
Building to the bigger array
These images are just the beginning of a new era in radio astronomy, starting with SKA pathfinders like ASKAP and culminating in the construction of the SKA radio telescope.
Once built, the SKA will comprise a vast army of radio receivers distributed over tens to hundreds of kilometres in remote areas of Western Australia and South Africa.
Just like ASKAP combines signals from several dishes, the SKA will use a supercomputer to build up a composite image of the sky.
Each ensemble of antennas will work together to photograph distant astronomical objects that are so faint, that they can’t be seen at all with current technology.
The SKA will thereby open up vast tracts of unexplored space to scientific study, making it a game-changer in astrophysical and cosmological research.