Study hopes to crack the code on how ice flows

Predicting climate change depends on many factors not properly included in current forecasting models, such as how the major polar ice caps will move in the event of melting around their edges. This in turn requires greater understanding of the processes at work when ice is under stress, influencing how it flows and moves. The immediate objective is to model the flow of ice sheets and glaciers more accurately, leading in turn to better future predictions of global ice cover for use in climate modeling and forecasting. Progress and future research objectives in the field were discussed at a recent workshop organized by the European Science Foundation (ESF), bringing together glaciologists, geologists, and experts in the processes of cracking under stress in other crystalline materials, notably metals and rocks.

The essential problem is that processes at different scales starting from the molecular and going up to whole ice sheets need to be integrated in order to develop models capable of accurate predictions. While the processes at the molecular level inside individual ice crystals are quite well understood, too little attention has been paid to the properties of ice at the scale of each grain, comprising organized groups of crystals. All crystalline solids, including metals, are comprised of grains, which are about 1 to 3 cms across in the case of ice. The grain is fundamental for ice movement, because of the strong mechanical anisotropy (irregularity) of individual ice grains. “These processes are much less understood, and one could say they are more ‘messy’,” said Paul Bons, who co-chaired the ESF workshop. “The challenge ahead is to convert the insight gained on the effects of grain-scale processes into improved rheological models.” Rheology is the study of how materials such as ice or rock flow when forces are applied to them.

As Bons noted, such knowledge of grain-level interactions is needed not just to construct better models of ice caps, but also for understanding processes inside the earth’s mantle, which could help predict earthquakes and volcanoes. “The interesting thing here is actually the similarity between all these compounds, not the differences,” said Bons, himself a geologist. “Essentially the same processes occur in ice, minerals and metals.”

The differences lie just in the balance between these processes, with interactions between crystals within grains being more significant in ice than metals or rocks. But as was noted by Sergio Faria, another co-chair, it is important to resolve these issues, since current models can be highly inaccurate in predicting ice flows, as has been found by analysing ice cores drilled into glaciers. “The microstructures observed in ice core samples indicate the deformation mechanisms active in an ice sheet,” said Faria. “Depending upon the sort of active mechanisms, the flow of an ice sheet may vary by orders of magnitude. Therefore a precise understanding of ice microstructures – and consequently of active deformation mechanisms – is essential to reduce the current uncertainty in ice sheet flow models.”

As a result of recent findings, the current approach to ice flow analysis, the so-called 3-layer model, will have to be revised, according to Sepp Kipfstuhl, the ESF conference’s third co-convenor. “It was interesting to see at the workshop that the study of microstructures challenges standard models for polar ice, especially the classical 3-layer model and the standard flow law of ice. This is an ‘inconvenient truth’ that complicates large-scale ice flow models, and hence impacts on climate modeling,” said Kipfstuhl.”

As in all branches of science, this inconvenient truth must be faced head on in order to solve the problem of accurate ice flow prediction, which has become all the more pressing in the light of current concerned over the impact of climate change.

The workshop Modelling And Interpretation Of Ice Microstructures was held April 2008 in Göttingen, Germany. Each year, ESF supports approximately 50 Exploratory Workshops across all scientific domains. These small, interactive group sessions are aimed at opening up new directions in research to explore new fields with a potential impact on developments in science.

Volcano ‘pollution’ solves mercury mystery

Measurements have shown that 7 tonnes of mercury escapes from the Masaya volcano every year.
Measurements have shown that 7 tonnes of mercury escapes from the Masaya volcano every year.

Scientists from the Universities of Oxford and Cambridge have discovered how volatile metals from volcanoes end up in polar ice cores.

‘It has always been a mystery how trace metals, like mercury, with a volcanic signature find their way into polar ice in regions without nearby evidence of volcanic activity,’ said Dr David Pyle of Oxford University’s Department of Earth Sciences who led the research team with colleague Dr Tamsin Mather. ‘These traces only appear as a faint ‘background signal’ in ice cores but up until now it has still been difficult to explain.’

The team sampled the fumes of two volcanoes; Mount Etna in Sicily and Masaya in Nicaragua. They pumped gases from the edges of the volcanic craters across some gold-plated sand, to measure the volatile metal mercury, and through very fine filters, to capture fume particles. They discovered that the gases at both volcanoes contain high levels of mercury vapour, and that the fume is also very rich in tiny particles, as small as 10-20 nanometres in size.

‘This is exciting and important since we didn’t know that volcanoes were a natural source of particles as small as this,’ said Dr Rob Martin of the University of Cambridge. ‘The existence of these particles is potentially very important for the climate system – they may control how clouds form, and how much solar energy reaches the Earth’s surface. What we don’t know yet, though, is what these nanoparticles are made of: whether they are tiny droplets of frozen magma, or salts that condense due to cooling of high-temperature volcanic fumes.’

The team were surprised by just how much mercury escapes from volcanoes.
The team were surprised by just how much mercury escapes from volcanoes.

The nanoparticles are small enough to be carried around the world and could be involved in the formation of clouds with dense concentrations of water droplets that reflect large amounts of solar radiation back into space. They may also ‘seed’ distant patches of barren ocean with nutrients.

Whilst researchers had suspected that mercury boils out of hot magma, the big surprise was just how much mercury escapes from volcanoes. Measurements made on just one part of the Masaya volcano in Nicaragua, by Dr Melanie Witt of Oxford University, have shown that about 7 tonnes of natural volcanic mercury escapes into the atmosphere from this vent each year.

‘That one vent of one volcano can produce 7 tonnes of mercury a year is astounding,’ said Oxford’s Dr Melanie Witt, ‘that’s considerably more than total industrial emissions of mercury from the UK – recorded at about 5.5 tonnes in 2000. It confirms our suspicions that volcanoes are an important part of the global mercury cycle: what we need to understand next is where this mercury ends up and what effects it may have on the environment.’

The research is reported in two papers in the Journal of Geophysical Research. The work was funded through research grants and research fellowships from the Royal Society, the Natural Environment Research Council (NERC) and the Leverhulme Trust.

Geothermal energy support heats up

The University of Adelaide has welcomed today’s announcement by the State Government offering further support to fast-track research and development of geothermal technology.

The State Government has today announced a further $250,000 towards geothermal energy research. This follows $250,000 provided last year to help develop an international research facility into geothermal (also known as “hot rock”) energy within the University, working with Geoscience Australia, the CSIRO, and the university research members of the Australian Geothermal Energy Group.

The University has this week signed an agreement with the State Government to help accelerate R&D of geothermal resources in South Australia.

“Today’s announcement is another welcome step forward in ensuring that our expertise in geothermal research is recognised throughout Australia and internationally, with great potential benefits for industry and the community,” says Professor Richard Russell, Pro Vice-Chancellor (Research Operations).

“The University of Adelaide’s researchers have worked extensively with the geothermal industry and are keen to ensure that this State remains at the forefront of research and development in this area. The State Government’s support is vital to making that happen,” Professor Russell says.

“Geothermal technology offers renewable and CO2 emissions-free electricity generation. Our work will become vital in helping the State to meet its strategic targets, both in terms of energy provision and by assisting the State to reduce its greenhouse gas emissions.”

Geothermal research will form a significant part of the University of Adelaide’s recently announced Institute for Mineral and Energy Resources. The Institute aims to become the premier research and educational facility for the mining and energy sectors in the Asia-Pacific region.

Professor Richard Hillis, Head of the Australian School of Petroleum, says: “South Australia is the national leader in the geothermal arena due to its unique geological endowment of hot rocks, and also due to a supportive State Government and a university sector that is addressing key issues in commercialising the technology.

“Momentum is building for geothermal energy in South Australia, and today’s announcement is a further sign that the State Government is serious about turning our research into a reality,” Professor Hillis says.

“We are already partnering with the Australian Geothermal Energy Group and the Department of Primary Industries and Resources SA (PIRSA), as well as individual companies hoping to become involved in geothermal energy production.

“Geothermal research projects are currently being undertaken in the Australian School of Petroleum, the School of Earth and Environmental Sciences and in the Schools of Mechanical and Chemical Engineering at the University of Adelaide. With the kind of support announced today, that reality of commercial geothermal electricity production in South Australia is getting closer.”

Rapid Climate Change: past; present; future

Key findings from an ambitious research project that provided the first ‘early detection system’ for climate changes in the Atlantic Ocean are highlighted today at a conference in London.

Most climate models predict gradual future changes to climate, related to the steadily increasing greenhouse gas concentrations. But ice and sediment core records reveal that, in the past, climate has changed abruptly – possibly in as little as 10 to 20 years. Such rapid change in the future could make prevention and adaptation strategies difficult and expensive to implement.

The need to understand the fundamental ocean processes that cause this abrupt change inspired the Natural Environment Research Council (NERC) to set up the £20m Rapid Climate Change programme.

A major part of the international programme involved deploying an array of instruments across the Atlantic from the Saharan coast of Africa to the Bahamas. It was risky – this type of monitoring had never been done before so there were no guarantees of success. But the risk was worth taking as, for the past four years, the instruments have provided scientists with a continuous and accurate record of the Atlantic’s Meridional Overturning Circulation (MOC), often referred to as the ‘Atlantic heat conveyor’, that moves warm water northwards and helps to maintain Europe’s mild climate.

Speaking at today’s conference, Ian Pearson, Minister for Science & Innovation, said, “We have made significant advances in the science that allows us to understand climate change, but governments still need more accurate climate predictions globally and regionally on timescales of months, years and decades.

“The Rapid Climate Change programme is vital in providing this data. Better knowledge of the state of the oceans will reduce uncertainty and improve regional climate predictions, particularly for north-west Europe.”

Research results from the programme revealed that, around 8,000 years ago, Newfoundland, the UK and northern Europe experienced extreme cold and dry conditions. Greenland temperatures were almost 6°C colder than present day. The shift to colder temperatures took only a few decades and lasted for about 160 years. It is thought that a rush of melt-water into the North Atlantic caused the slowdown of the Atlantic conveyor, leading to the colder conditions.

By combining data from past records with the new measurements obtained from the instrument array, the scientists have been able to reconstruct the behaviour of the Atlantic conveyor over the past 50 years. The reconstruction is helping them to understand recent climate changes. It also allows them to gauge the accuracy of the current climate models and the future predictions of change.

Professor Alan Thorpe, Chief Executive of NERC, said, “The RAPID programme has provided the first evidence of large, natural variability in the Atlantic circulation, much greater knowledge of how and why abrupt changes happened in the past, and the means to improve climate models. We now need to look to the future. The programme has already proved how valuable the continuous monitoring record is to current understanding of climate change and to future climate models. As a result, NERC has made a commitment to fund the observing system for a further six years, until 2014.”

The next phase of the Rapid Climate Change programme is known as RAPID-WATCH. NERC is providing &pound16m to continue monitoring the Atlantic conveyor, and to assess the scientific and broader benefits of having a more permanent operational system. Matching funds have been committed by the National Science Foundation and the National Oceanic & Atmospheric Administration in the United States, to complete the transatlantic monitoring array.

The research will involve scientists from the UK, Canada, Germany and the USA, working in close collaboration with the Met Office Hadley Centre to feed results from the programme into the Centre’s decadal prediction system.

Fire under the ice

The installation of a seismometer on an ice floe. - Credit: Chris Linder, Alfred Wegener Institut
The installation of a seismometer on an ice floe. – Credit: Chris Linder, Alfred Wegener Institut

International expedition discovers gigantic volcanic eruption in the Arctic Ocean

An international team of researchers was able to provide evidence of explosive volcanism in the deeps of the ice-covered Arctic Ocean for the first time. Researchers from an expedition to the Gakkel Ridge, led by the American Woods Hole Oceanographic Institution (WHOI), report in the current issue of the journal Nature that they discovered, with a specially developed camera, extensive layers of volcanic ash on the seafloor, which indicates a gigantic volcanic eruption.

“Explosive volcanic eruptions on land are nothing unusual and pose a great threat for whole areas,” explains Dr Vera Schlindwein of the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association. She participated in the expedition as a geophysicist and has been, together with her team, examining the earthquake activity of the Arctic Ocean for many years. “The Vesuvius erupted in 79 AD and buried thriving Pompeii under a layer of ash and pumice. Far away in the Arctic Ocean, at 85° N 85° E, a similarly violent volcanic eruption happened almost undetected in 1999 – in this case, however, under a water layer of 4,000 m thickness.” So far, researchers have assumed that explosive volcanism cannot happen in water depths exceeding 3 kilometres because of high ambient pressure. “These are the first pyroclastic deposits we’ve ever found in such deep water, at oppressive pressures that inhibit the formation of steam, and many people thought this was not possible,” says Robert Reves-Sohn, staff member of the WHOI and lead scientist of the expedition carried out on the Swedish icebreaker Oden in 2007.

Bathymetric chart of the Gakkel Ridge at 85°E. Photographic bottom surveys were conducted along profiles shown as thin, black lines. The photo showing volcanic ashes on the sea bed were taken at the site, which is marked with a red star and the letter a.
Bathymetric chart of the Gakkel Ridge at 85°E. Photographic bottom surveys were conducted along profiles shown as thin, black lines. The photo showing volcanic ashes on the sea bed were taken at the site, which is marked with a red star and the letter a.

A major part of Earth’s volcanism happens at the so-called mid-ocean ridges and, therefore, completely undetected on the seafloor. There, the continental plates drift apart; liquid magma intrudes into the gap and constantly forms new seafloor through countless volcanic eruptions. Accompanied by smaller earthquakes, which go unregistered on land, lava flows onto the seafloor. These unspectacular eruptions usually last for only a few days or weeks.

The Gakkel Ridge in the Arctic Ocean spreads so slowly at 6-14 mm/year, that current theories considered volcanism unlikely – until a series of 300 strong earthquakes over a period of eight months indicated an eruption at 85° N 85° E in 4 kilometres water depth in 1999. Scientists of the Alfred Wegener Institute became aware of this earthquake swarm and reported about its unusual properties in the periodical EOS in the year 2000.

Vera Schlindwein and her junior research group are closely examining the earthquake activity of these ultraslow-spreading ridges since 2006. “The Gakkel Ridge is covered with sea-ice the whole year. To detect little earthquakes, which accompany geological processes, we have to deploy our seismometers on drifting ice floes.” This unusual measuring method proved highly successful: in a first test in the summer 2001 – during the “Arctic Mid-Ocean Ridge Expedition (AMORE)” on the research icebreaker Polarstern – the seismometers recorded explosive sounds by the minute, which originated from the seafloor of the volcanic region. “This was a rare and random recording of a submarine eruption in close proximity,” says Schlindwein. “I postulated in 2001 that the volcano is still active. However, it seemed highly improbable to me that the recorded sounds originated from an explosive volcanic eruption, because of the water depth of 4 kilometres.”

The scientist regards the matter differently after her participation in the Oden-Expedition 2007, during which systematic earthquake measurements were taken by Schlindwein’s team in the active volcanic region: “Our endeavours now concentrate on reconstructing and understanding the explosive volcanic episodes from 1999 and 2001 by means of the accompanying earthquakes. We want to know, which geological features led to a gas pressure so high that it even enabled an explosive eruption in these water depths.” Like Robert Reves-Sohn, she presumes that explosive eruptions are far more common in the scarcely explored ultraslow-spreading ridges than presumed so far.

Mini subs to probe odd structures in BC lake

Single person submersibles have been called in to help scientists retrieve samples from a lake in northern British Columbia that may hold vital clues to the history of life on Earth and on other planets.

Greg Slater, an environmental geochemist in the Faculty of Science, says the objects of scientific interest are unique carbonate rock structures, known as microbialites because they are covered with microbes. Some of these microbialites grow at depths up to 180 feet below the water’s surface, too deep to reach by non-decompression SCUBA diving.

“Are they the result of biological or geological processes? Why are there different microbes living on them and how long have these microbial communities been preserved? These are some of our big questions,” says Slater, who joined the international team researching these curious specimens three years ago.

Last fall, the project received welcome support from Nuytco Inc., manufacturer of single-person Deepworker submersibles, who offered two subs to enableresearchers to finally collect samples of the deepest microbialites. The dives will begin June 23.

“It’s going to help us develop a baseline of understanding about life on our planet,” says Slater. “As amazing as it sounds, the bottom of a lake can answer lots of questions about life on Earth. And how we explore this Lake will lay the groundwork for how we will explore Mars.”

Astronaut Dave Williams, now a professor of surgery at McMaster University, will also participate in the research at Pavilion Lake. Trained as a Deepworker pilot, he is interested in the similarities between field scientific activities in the submersible and using a lunar rover for geological research in future missions sending astronauts back to the Moon.

“What’s new about the work at Pavilion Lake this summer is the use of advanced underwater exploration technology to enable investigators to study previously inaccessible specimens,” says Williams. “Now we’re able to use Rover-type subs with robotic arms similar to what is envisioned for exploring the lunar surface.”

Pavilion Lake is located about 500 kilometres north of Vancouver in Marble Canyon Provincial Park. It was formed by a glacier more than 10,000 years ago, and has for the last decade been the site of several studies into astrobiology.

Scientists Detail the Effects of Climate Change on Extreme Weather in North America

A scientific assessment that provides the first comprehensive analysis of observed and projected changes in weather and climate extremes in North America and U.S. territories was released today by the U.S. Climate Change Science Program (CCSP) and the Subcommittee on Global Change Research.

Among the major findings reported are that droughts, heavy downpours, excessive heat, and intense hurricanes are likely to become more commonplace as humans continue to increase the atmospheric concentrations of heat-trapping greenhouse gases.

The report is based on scientific evidence that a warming world will be accompanied by changes in the intensity, duration, frequency, and geographic extent of weather and climate extremes.

The CCSP report was co-chaired by Tom Karl, director of NOAA’s National Climate Data Center in Asheville, North Carolina, and NCAR senior scientist Gerald Meehl.

“This report addresses one of the most frequently asked questions about global warming: What will happen to weather and climate extremes? This synthesis and assessment product examines this question across North America and concludes that we are now witnessing and will increasingly experience more extreme weather and climate events,” says Karl.

“We will continue to see some of the biggest impacts of global warming coming from changes in weather and climate extremes,” says Meehl. “This report focuses for the first time on changes of extremes specifically over North America.”

Other authors of the report include NCAR scientists Gregory Holland and Linda Mearns. Holland was among the lead authors of Chapter 2 on “Observed changes of weather and climate extremes.” He and Mearns were also on the team of lead authors for Chapter 3 on “How well do we understand the causes of observed changes in extremes, and what are the projected future changes?”

The Intergovernmental Panel on Climate Change previously evaluated extreme weather and climate events on a global basis in this same context. However, there has not been a specific assessment across North America prior to this report.

The full CCSP 3.3 report, Weather and Climate Extremes in a Changing Climate, and a summary FAQ brochure are available online from the U.S. Climate Change Science Program.

Ice cores map dynamics of sudden climate changes

Ice core drilling NorthGRIP Greenland - Credit: Niels Bohr Institute, University of Copenhagen
Ice core drilling NorthGRIP Greenland – Credit: Niels Bohr Institute, University of Copenhagen

New, extremely detailed data from investigations of ice cores from Greenland show that the climate shifted very suddenly and changed fundamentally during quite few years when the ice age ended. Researchers from the Niels Bohr Institute of University of Copenhagen have together with an international team analysed the ice cores from the NorthGRIP drilling through the Greenland ice cap, and the epoch-making new results have been published in the highly esteemed scientific journal Science and in Science Express.

The ice in Greenland has been formed by snow that stays year after year and is gradually compressed into a thick ice cap. The annual layers inform us about the climate during the years when the snow was falling so the ice is a record of the climate of the past, and ice core drillings through the three km thick ice cap show the climate 125,000 years back in time.

In the Northern Hemisphere the last glacial ended in strong variations of temperature, which consisted of two warming periods interrupted by a cold period. The first sudden warming happened 14,700 years ago. The temperature in Greenland increased by more than 10 degrees, and in the milder climate, called the Bølling period, the first people of the Stone Age went towards Northern Europe and Scandinavia. But joy did not last long. 12,900 years ago the ice age stroke once more with a new severely cold period, which lasted until 11,700 years ago, at which time the ice age ended ultimately. The ice cores from Greenland, which reflect the climate in the Northern Hemisphere, show that tremendously fast climatic changes were involved.

The ice age ended in one year

“We have analysed the transition from the last glacial till our present warm interglacial period, and the climatic shifts are happening so suddenly as if somebody had pushed a button”, says Dorthe Dahl-Jensen, Professor at the Centre for Ice and Climate at the Niels Bohr Institute of the University of Copenhagen.

The new data from the ice cores show that the climate shifted from one year to the next. The annual layers of the ice have been analysed in a very high resolution for a number of components that in their own way tell us about the climate.

Dust. The amount of dust has been measured. The colder the climate is, the more dust is available in the atmosphere of the Earth, and the more dust is blowing over the land settling on the ice cap.

Oxygen. The amount of the special oxygen-isotope O-18 has been measured, and tells about the temperature where the atmospheric precipitation is formed. The higher the content of the oxygen-isotope O-18, the warmer is the climate locally in the place of atmospheric precipitation.

Hydrogen. Also the amount of the special hydrogen-isotope deuterium has been measured. Excess of deuterium reflects the temperature at the places where the precipitation vapour originally comes from. The air masses are circulating around the earth, and the greater excess of deuterium, the warmer was the climate in the original area.

By comparing the content of dust, oxygen and hydrogen in the annual layers of the ice cores the researchers can now investigate how a climatic shift develops year by year.

At first the dust content begins to change and decreases to one tenth over some decades. As the dust in the ice derives from Asia the researchers conclude that there have been climatic changes far from Greenland.

“Some years later the atmospheric precipitation starts to change. Our measurements show that the excess of deuterium in relation to O-18 changes in quite few years. This means that the vapour coming to Greenland changes source areas. The conclusion is that extremely fast and dramatical changes of the weather systems have taken place over the Atlantic”, says Sune Olander Rasmussen, ice core researcher at the Centre for Ice and Climate at the Niels Bohr Institute.

The new results help mapping out how climatic shifts happen, and which climatic processes are the most important during these changes.

“Even though the climatic changes at the end of the ice age are seen most violently in the Northern Atlantic regions our measurements suggest that they are initiated by changes in the tropical areas. We can also see that when abrupt climate change is going on, it is the atmospheric circulation that has changed fundamentally”, concludes Dorthe Dahl-Jensen.

The new information about the climate of the past is important knowledge for the improvement of the climate models used for predicting the climate of the future.

Iron Isotope Composition in Lava Lake Points to Possible Ways to Trace Planetary Origins

This view from the present-day Kilauea Iki overlook shows lava flowing into what is now known as the Kilauea iki lava lake. Researchers determined that samples from the lake have differences in the iron isotope composition that point to new ways of studying the origins of the earth and other planets.
This view from the present-day Kilauea Iki overlook shows lava flowing into what is now known as the Kilauea iki lava lake. Researchers determined that samples from the lake have differences in the iron isotope composition that point to new ways of studying the origins of the earth and other planets.

A University of Arkansas researcher and his colleagues have found differences in the iron isotope composition of basalts from a lava lake in Hawaii that point to new ways of studying the origins of the earth and other planets.

Fang-Zhen Teng, assistant professor of geosciences and a member of the Arkansas Center for Space and Planetary Sciences, Nicholas Dauphas of the department of geophysical sciences and a member of the Enrico Fermi Institute at the University of Chicago, and Rosalind T. Helz of the U.S. Geological Survey report their findings in the June 20 issue of the journal Science.

The researchers examined iron isotopes in basalt samples from the Kilauea Iki lava lake on the main island of Hawaii. Isotopes have the same chemical properties but different weights, so some processes cause what looks like the same material to behave differently – often separating the two. Such separation can tell scientists something about how the material containing the isotopes formed.

However, until now scientists thought that such isotope fractionation only occurred at low temperatures and with elements of low molecular weight. Because of the heat and iron’s molecular weight, scientists thought that the process that formed basalts did not separate iron isotopes.

“There is a huge dispute on this topic,” Teng said. “Our research shows that there is clearly fractionation.”

Teng likens the change in iron isotopic composition in basalts to the baking of a cake: With a cake, you start out with certain ingredients, but the baking process changes the ingredients and their proportions within the cake. In the same way, the process that makes basalt magma through partial melting of the mantle peridotites, or rocks, changes the iron isotope compositions.

Past studies have examined basalts, but found little or no separation of iron isotopes. However, no one was studying the individual minerals found within a basaltic rock.

“We analyzed not only the whole rocks, but the separate minerals,” Teng said. The minerals examined showed a significant separation of iron isotopes, in contrast to the whole rocks. The researchers looked at olivine crystals, better known as peridot in the jewelry world, which formed and sank as the lava lake cooled.

“This research gives scientists a new tool to investigate the question of planetary differentiation,” said Dauphas. If basalts from the moon or Mars have similar iron isotope separation, it suggests that they formed through heat processes similar to those on Earth. However, if rocks from these planetary bodies do not have iron isotope separation, it suggests that they were formed in a different way.

The next project by Teng, who teaches in the J. William Fulbright College of Arts and Sciences, will be to study the isotopic composition of iron in lunar basalts returned by the Apollo missions.

Active submarine volcanoes found near Fiji

A multibeam sonar three-dimensional image of the recently discovered volcano named Lobster - Photo by: Richard Arculus, Australian National University
A multibeam sonar three-dimensional image of the recently discovered volcano named Lobster – Photo by: Richard Arculus, Australian National University

Several huge active submarine volcanoes, spreading ridges and rift zones have been discovered northeast of Fiji by a team of Australian and American scientists aboard the Marine National Facility Research Vessel, Southern Surveyor.

On the hunt for subsea volcanic and hot-spring activity, the team of geologists located the volcanoes while mapping previously uncharted areas. Using high-tech multi-beam sonar mapping equipment, digital images of the seafloor revealed the formerly unknown features.

The summits of two of the volcanoes, named ‘Dugong’, and ‘Lobster’, are dominated by large calderas at depths of 1100 and 1500 metres.

During the six-week research expedition in the Pacific Ocean, scientists from The Australian National University (ANU), CSIRO Exploration & Mining and the USA, collaborated to survey the topography of the seafloor, analysing rock types and formation, and monitoring deep-sea hot spring activity around an area known as the North Lau Basin, 400 kilometres northeast of Fiji.

The voyage’s Chief Scientist, ANU Professor Richard Arculus describes the terrain – the result of extreme volcanic and tectonic activity – as spectacular. “Some of the features look like the volcanic blisters seen on the surface of Venus,” he says.

“These active volcanoes are modern day evidence of mineral deposition such as copper, zinc, and lead and give an insight into the geological make-up of Australia,” he says.

“It provides a model of what happened millions of years ago to explain the formation of the deposits of precious minerals that are currently exploited at places like Broken Hill and Mt Isa. It may also provide exploration geologists with clues about new undiscovered mineral deposits in Australia.

“These deep-sea features are important in understanding the influences that have shaped not only our unique continent but indeed the whole planet,” Professor Arculus says.

Such discoveries highlighted man’s lack of knowledge about the world’s oceans. “We know more about the surface of Mars than we know about the ocean seafloor,” Professor Arculus says.

CSIRO’s Director of Research Vessels, Captain Fred Stein, says the expedition was a humbling experience. “It was a reminder that at the beginning of the 21st century it is still possible – on what is often regarded as a thoroughly explored planet – to discover a previously unknown massif larger than Mt Kosciuszko,” he says.

“We are fortunate that we can offer the scientific capability of the Southern Surveyor to Australian scientists. It’s the only Australian research vessel that can provide the opportunity to conduct such valuable research to make these kinds of discoveries possible.”