El_Cid

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About El_Cid

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  1. 'It's all a giant conspiracy! (To some readers of climate blogs)': http://arstechnica.com/science/2012/09/its-all-a-giant-conspiracy-to-some-readers-of-climate-blogs/
  2. http://arstechnica.com/science/2012/08/antarctic-ice-sheets-may-have-changed-the-planets-heartbeat/ 'Antarctic ice sheets may have changed the planet's heartbeat': "You may have seen them before—the graphs from Antarctic ice cores showing the heartbeat of “ice ages” (or glaciations). If so, you probably noted a cyclical pattern, with each glaciation lasting about 100,000 years before being abruptly interrupted by a relatively brief warm period—the interglacial. Soon, the slow freeze inexorably gripped the planet again. There's a reason for this rhythmic pattern—cycles in Earth’s orbit that subtly alter the sunlight reaching the Earth. But the graphs have long contained a couple head-scratching mysteries to climate scientists, though. First, why is the 100,000 year cycle dominant? There are several orbital cycles—some around 20,000 years long, another about 41,000 years long, and then the 100,000 year cycle. By itself, the 100,000 year cycle changes things the least, yet it drives the glacial heartbeat. There are some good answers to that question, but then there’s the other mystery: once you look back about a million years into the past, the heartbeat changes. Instead of glacial cycles 100,000 years long, a more rapid pulse of 41,000 years becomes the norm. Something happened to change that. Here, too, there are some hypotheses, but the data to test them has been scarce. Enter a new study from researches at the University of Cambridge. The study presents 1.5 million years of climate history recorded in ocean sediments off the eastern shore of New Zealand. As with most ocean cores, the team measured isotopes of oxygen in the calcium carbonate shells of single-celled foraminifera. (The same isotopes are used to extract climate records from ice cores.) While those cores are astonishing libraries of climate history, they are complicated by the fact that the oxygen isotopes in those shells are tracking more than one variable. The amount of water that ends up trapped in ice sheets on the continents (lowering sea level) alters the isotopic ratio in the ocean. This means that changes in the record indicate changes in the volume of ice present on the planet. At the same time, the temperature of the ocean water affects the chemistry of the foraminifera’s shell growth, and this affects the isotopic signature as well. One way to account for this confusion is to find a separate proxy that only records temperature. The ratio of magnesium to calcium (magnesium can take the place of calcium in carbonate shells) does just that. When you subtract the effect of temperature change from the oxygen isotope signal, you’re left with only one thing: ice volume. This isn’t a new technique, but its application to the transition from 41,000 year glacial cycles to 100,000 year ones makes this record very valuable. Researchers studying the transition have mostly had to do so through smudged lenses—using climate records that couldn’t differentiate between temperature change and ice sheet behavior. Existing records generally indicate that the transition was gradual, phasing in over a period of 500,000 years or so as glaciations grew colder. In contrast, this new record shows no trend in temperature and a sudden transition in ice volume, which hit a new maximum 900,000 years ago. Glaciations flipped into a different mode from then on. While the details of this study may be different, it's not the first to provide evidence that ice sheets grew larger during this time. This growth is the best explanation available for the change to 100,000 year glacial cycles. Beyond a certain size, ice sheets become more stable in some ways—the high altitude region of the ice sheet sticks its head into cooler air at higher elevation, for example. Larger ice sheets could withstand the orbital warming nudge that previously ended glaciations after 41,000 years. The most likely candidates for that increase in ice sheet volume have been the Northern Hemisphere ice sheets, but this new study proposes that the critical change may have occurred in Antarctica. The record reflects ocean conditions near Antarctica, whereas the coverage of other ocean sediment cores covering this timeframe have been biased toward the North Atlantic. Since the new record differs from the others, it suggests the Antarctic ice sheet were not marching in step with the Northern Hemisphere ice sheets. And there’s good reason to think that the Antarctic ice sheet could have “gone rogue.” The rise in incoming solar radiation at the end of the 41,000 year period just prior to the increase in ice volume was very weak, which could have allowed the Antarctic ice to skip the usual melt, and then grow to a new maximum size. (Because it’s summer solar radiation that matters, orbital changes for the two hemispheres are not synchronized— only the Southern Hemisphere experienced these unusual conditions.) After skipping that beat, the researchers think this larger Antarctic ice sheet could have guided the climate into the 100,000 year groove. In a perspective published in the same issue of Science, Oregon State’s Peter Clark writes, “Confirmation of these hypotheses will require generation of similar-quality… data sets, which should help to better understand the range of regional variability in deep-ocean temperature and [oxygen isotope signature].” Are there other explanations for the pattern seen in this climate record? Answering that question will require more ice volume records from more locations, each of which will dispel a bit more of the mystery surrounding this pivotal transition in Earth’s climate system." -------------------------------- links and pics in the article proper
  3. 'Australia rallies support for super-trawler vote': http://www.bbc.co.uk/news/world-asia-19566909 "Australia's government is working to rally support for a bill preventing a super-trawler fishing in its waters, after the opposition spoke out against the move. The bill, introduced on Tuesday, aims to stop the vessel from fishing for two years while more research is conducted. Fishermen and environmental groups fear the Dutch-owned trawler will over-fish. But Australia's fishing authority has dismissed these fears, saying the catch will be managed. Its ''robust management of fisheries will ensure that any fishing is sustainable'', the Australian Fisheries Management Authority (AFMA) said. Environment Minister Tony Burke introduced the legislation in parliament on Tuesday and is now looking to independent MPs to support the vote, after the opposition called the law a ''Trojan horse''. "It allows the minister to ban any fishing in Australia of any kind - recreational fishing, charter fishing, commercial fishing - on the basis of the minister deciding it has a 'social impact'," said opposition lawmaker Christopher Pyne. The 9,500-tonne, 143m Abel Tasman super-trawler - formerly named the FV Margiris - is currently docked at Port Lincoln in South Australia. Activists and local fishermen have been protesting for months, citing concerns over over-fishing, by-fishing - whereby other marine life gets swept up in the net - and wider impact on the environment. Given the ''uncertainties'' over the consequences for species such as dolphins and seabirds, Mr Burke said, he would take a cautious stand. "If we get this wrong, there are risks to the environment, to commercial operators and to everyone who loves fishing and they are risks I am not prepared to take," he added. Seafish Tasmania, the company that brought the boat to Australia, had planned to fish in waters from Western Australia to southern Queensland. It had obtained approval from AFMA for a quota of two types of fish. The independent fishing authority has tried to allay fears, saying that it enforces stringent catch limits and strict regulations to ensure sustainability. ''AFMA has found no evidence that larger boats pose a higher risk to either commercial species or broader marine ecosystem when total catches are limited and the limits are enforced,'' said a statement on the AFMA website. Despite this those opposed to the controversial trawler, which would be the biggest boat to fish in Australian waters, remain unconvinced and want more research done. Activist groups want the Australian government to impose a ban on all super-trawlers. "These ships literally vacuum up entire schools of fish. You could fly a jumbo jet through the opening of its net with room to spare," said Greenpeace Australia Pacific oceans campaigner Nathaniel Pelle in a statement. However, AFMA maintains that the net used by the Abel Tasman is ''not at all the biggest net in the current Australian fishing fleet''. It also added that the reason for the vessel's vast size is that it has a factory and freezer on board - two thirds of the trawler are for processing and storage." --------------------------- There are very destructive to the general habitat and fish stocks, you really don't want these super trawlers near your fishing grounds.
  4. 'Milky Way's black hole to eat planet-forming cloud': http://www.bbc.co.uk/news/science-environment-19558443 "A young star and its planet-forming cloud are being pulled towards the huge black hole at the centre of our galaxy, astronomers say. Like other galaxies, the Milky Way hosts a black hole, known as Sagittarius A* (SgrA*), at its centre. SGrA* dislodged the star from its original orbit within a ring of young suns circling the black hole. The disc of gas and dust will be devoured before it can evolve into a solar system. The research by a team at the Harvard-Smithsonian Center for Astrophysics in Cambridge, US, is published in Nature Communications journal. Earlier this year, researchers reported seeing a cloud of ionised gas and dust falling in towards SgrA*. They suggested that it formed when gas streaming from two nearby stars collided, like wind-blown sand gathering into a dune. Astronomers Ruth Murray-Clay and Abraham Loeb have come up with a different explanation: that the cloud is a proto-planetary disc surrounding a low-mass star. Newborn stars retain a surrounding disc of gas and dust for millions of years. If one such star were to dive toward our galaxy's central black hole, radiation and gravitational tides would rip apart the surrounding matter in just a few years. The star is now hurtling towards the black hole on an elliptical orbit. While the star itself is too small to be directly observed, the proto-planetary dust cloud accompanying it is being disrupted on the way, and it is this debris that the researchers were able to detect. "This unfortunate star got tossed toward the central black hole. Now it's on the ride of its life," said Dr Murray-Clay. As the young sun continues to plummet towards the black hole over the next year, more of the disc's outer material will be torn away. The stripped gas will swirl into the yawning black hole. Friction will heat it to high enough temperatures that it will glow in X-rays. But while the planetary cloud is heading for destruction, the star is likely to survive. "The tidal forces from the black hole are strong enough to strip gas away from the star but not strong enough to pull the star itself apart," Dr Murray-Clay told BBC News. "The same sort of forces that generate ocean tides are at work here. Ocean tides happen when the oceans are pulled away from the Earth a little bit by the Moon. In our case, the black hole is generating such strong tidal forces that they pull a large fraction of the disc entirely away from the star. "The inner portion of the disc will survive - gas close to the young star is held more tightly since it is deeper in the star's gravitational well." The results are interesting because the centre of the Milky Way should be a very inhospitable place to try to form a planet. Stars crowd each other as they zip through space while exploding stars unleash shock waves and bathe the region in intense radiation. The powerful gravitational forces from a supermassive black hole twist and warp the fabric of space itself. The research suggests, contrary to received wisdom, that planets can still form in this cosmic war zone. Although this protoplanetary disc is being destroyed, the stars that remain in the ring can hold onto their planet-forming clouds. This means they could form planets despite the hostile surroundings. "It's fascinating to think about planets forming so close to a black hole," said Abraham Loeb." ----------------------------------
  5. He is not a communist. He may be a marxist. Is that possible to compute? And funny how your first response was, "It was only 30 years ago where an outspoken communist would be locked up and tortured. Now it seems the world is full of them. Such a shame.". That speaks volumes about you (and is not the first time you've pulled this 'shame we can't kill them for their different view from mine' thing). So i've come to hard decision. In the same way we have come to find out that kind of character Brad Wardell really is, i've come to that situation with yourself Dale. So, sorry, but your not the guy i thought you were once, not one i wish to talk to much as your clearly 'near fascist' personality comes to the fore, your ugly and i'm done talking with you, so please carry on without expecting any input from me in your 'debates'(which is one sided insults most of the time) etc. Your not worth my time. --------------------------------------- But for others that feel there may be a different way to run the world other than let a tiny minority steal our rights away from us (as outlined in those video's i posted, before Dale resorted to moving attention away from the content to character insults etc), here is another very good Chomsky video from 2011: There are options out there, we do not have to become slaves to the minority.
  6. And to counter balance my more serious postings, something to make everything fine 'David Icke Awesome NEW Interview June 18, 2012': (personally, i'd pay more attention to the other stuff i post )
  7. he is not a Communist, infact he has serious misgivings about various communist like systems (venezula) etc, he studied communism through marxs works, and found it interesting in the wider topic of why the world currently works as it does. Infact there is a longer +1 hour video that goes into more detail, but i figure the 'lite' version was probably as much as need be given here. This is another interesting video (not related other than on the same kind of topics), not so sure on everything as it is very american-centric, but it seems legit enough:
  8. 'More planets could harbour life': http://www.bbc.co.uk/news/science-environment-19545186 "New computer models suggest there could be many more habitable planets out there than previously thought. Scientists have developed models to help them identify planets in far-away solar systems that are capable of supporting life. Estimates of habitable planet numbers have been based on the likelihood of them having surface water. But a new model allows scientists to identify planets with underground water kept liquid by planetary heat. The research was presented at the British Science Festival in Aberdeen. Water is fundamental for life as we know it. Planets too close to their sun lose surface water to the atmosphere through evaporation. Surface water on planets located in the more frigid distant reaches from their sun is locked away as ice. The dogma was, for water to exist in its life-giving liquid form, a planet had to be the right distance from its sun - in the habitable zone. As Sean McMahon, the PhD student from Aberdeen University who is carrying out the work explained: "It's the idea of a range of distances from a star within which the surface of an Earth-like planet is not too hot or too cold for water to be liquid. "So traditionally people have said that if a planet is in this Goldilocks zone - not too hot and not too cold - then it can have liquid water on its surface and be a habitable planet" But researchers are starting to think that the Goldilocks theory is far too simple. Planets can receive two sources of heat - heat direct from the star and heat generated deep inside the planet. As you descend through the crust of the Earth, the temperature gets higher and higher. Even when the surface is frozen, water can exist below ground. Immense quantities of water in fact - teeming with primitive life. As Prof John Parnell, also from Aberdeen University said: "There is a significant habitat for microorganisms below the surface of the Earth, extending down several kilometres. "And some workers believe that the bulk of life on Earth could even reside in this deep biosphere." So the Aberdeen team are developing models to predict which far-flung planets might harbour underground reservoirs of liquid water with the possibility of alien life. Explaining their rationale, Mr McMahon said: "If you take into account the possibility of deep biospheres, then you have a problem reconciling that with the idea of a narrow habitable zone defined only by conditions at the surface." As you move away from the star the amount of heat a planet receives from the star decreases and the surface water freezes - but any water held deep inside will stay liquid if the internal heat is high enough - and that water could support life. Even a planet so far from the star that it receives almost no solar heat could still maintain underground liquid water. According to Mr McMahon, "There will be several times more [habitable] planets"." --------------------------------------- +
  9. This is quite a nice shortish (30 odd minutes) youtube lecture from David Harvey, looking at the financial crash and capitalism: I just came across it and feel there is some merit in his critique, worth consideration at any rate, and this is his bio: http://en.wikipedia.org/wiki/David_Harvey_%28geographer%29 He is an expert of Marxism, and while i'm not into that as a whole, it gives his critique a nice different perspective.
  10. And all she was doing was giving due warning that she is likely going to decide to do this. That was the point of her speech.
  11. No. She made a choice. Rather than let her lay-about siblings get their inheritance their parents wanted them to get, she 'judged' them not worthy and blocked it. Does that sound about the long and short of it?
  12. 'Desert regions growing due to climate change' - google: http://thinkprogress.org/climate/2011/03/20/207725/population-flight-from-growing-desert-of-central-texas/?mobile=nc https://webcache.googleusercontent.com/search?q=cache:I5wGHVx9YO8J:http://www.unep.org/geo/gdoutlook/045.asp%2BDesert+regions+growing+due+to+climate+change&oe=utf-8&rls=org.mozilla%3Aen-GB%3Aofficial&client=firefox-a&gbv=1&sei=g7NNUL_IHq-U0QWLooCAAQ&hl=en&ct=clnk http://www.worldpreservationfoundation.org/topic.php?cat=climateChange&vid=23 http://dsc.discovery.com/news/2009/08/19/desert-expansion.html etc etc. I know one of your tactics is to paint me as a fringe lunatic, but erm.......pot kettle much? Now we can debate the science on wether under climate change that is currently warming (that even the sceptic scientists admit is true) Deserts are increasing or not, or likely to etc. But the idea, the cause and effect, is not purely insane and i'm not the only person to mention it, or the first to have thought about it, the internet tells that story quite well ----------------------------------------- 'Caribbean coral reefs face collapse': http://www.guardian.co.uk/environment/2012/sep/10/caribbean-coral-reefs-collapse-environment " Caribbean coral reefs – which make up one of the world's most colourful, vivid and productive ecosystems – are on the verge of collapse, with less than 10% of the reef area showing live coral cover. With so little growth left, the reefs are in danger of utter devastation unless urgent action is taken, conservationists warned. They said the drastic loss was the result of severe environmental problems, including over-exploitation, pollution from agricultural run-off and other sources, and climate change. The decline of the reefs has been rapid: in the 1970s, more than 50% showed live coral cover, compared with 8% in the newly completed survey. The scientists who carried it out warned there was no sign of the rate of coral death slowing. Coral reefs are a particularly valuable part of the marine ecosystem because they act as nurseries for younger fish, providing food sources and protection from predators until the fish have grown large enough to fend better for themselves. They are also a source of revenue from tourism and leisure. Carl Gustaf Lundin, director of the global marine and polar programme at the International Union for Conservation of Nature (IUCN), which published the research, said: "The major causes of coral decline are well known and include overfishing, pollution, disease and bleaching caused by rising temperatures resulting from the burning of fossil fuels. Looking forward, there is an urgent need to immediately and drastically reduce all human impacts [in the area] if coral reefs and the vitally important fisheries that depend on them are to survive in the decades to come." Warnings over the poor state of the world's coral reefs have become more frequent in the past decades as pollution, increasing pressure on fish stocks, and the effects of global warming on the marine environment – in the form of higher sea temperatures and slightly elevated levels of acidity in the ocean – have taken their toll. Last year, scientists estimated that 75% of the Caribbean's coral reefs were in danger, along with 95% of those in south-east Asia. That research, from the World Resources Institute, predicted that by 2050 virtually all of the world's coral reefs would be in danger. This decline is likely to have severe impacts on coastal villages, particularly in developing countries, where many people depend on the reefs for fishing and tourism. Globally, about 275 million people live within 19 miles of a reef. IUCN, which is holding its quadrennial World Conservation Congress on Jeju island in South Korea this week, said swift action was vital. The organisation called for catch quotas to limit fishing, more marine-protected areas where fishing would be banned, and measures that would halt the run-off of fertilisers from farmland around the coast. To save reefs around the world, moves to stave off global warming would also be needed, the group said. On a few of the more remote Caribbean reefs, the situation is less dire. In the Netherlands Antilles, Cayman Islands and a few other places, the die-off has been slower, with up to 30% coverage of live coral still remaining. The scientists noted that these reefs were in areas less exposed to human impact from fishing and pollution, as well as to natural disasters such as hurricanes. The report – compiled by 36 scientists from 18 countries – was the work of the IUCN-coordinated Global Coral Reef Monitoring Network." -------------------------- links in the article proper I should just add that not ALL links in the gaurdian articles are directly related to the topic, they seem to use some of that 'key word' linking thing that will just take you to something not related to the article, so you have to work out which are 'info' links on the topic, and which are 'advert(?)' links.
  13. 'Don't give climate change heretics an easy ride': http://www.guardian.co.uk/commentisfree/2012/aug/31/climate-change-heretics-media-easy-ride " No one would want a novelist to perform brain surgery with her biro. No one would want a man with a PhD in political science to then write textbooks claiming that those misadventures are best medical practice. Society understands the architecture of academia and knows there are relevant qualifications in different fields, and the media accepts the idea of specialisations and accords greater respect to those with greater expertise. With one exception: climate science. When it comes to this academic discipline, it seems that if you are a specialist in public sector food-poisoning surveillance or possess a zoology doctorate on sexual selection in pheasants, editors will seek your contrarian views more avidly than if you have qualifications in climate science and a lifetime's professional expertise. The press is further littered with climate "heretics" almost all of whom have academic backgrounds in history, literature, and the classics with a diploma in media studies. (All these examples are true.) One botanist trying to argue that glaciers were advancing took his data (described as simply false by the World Glacier Monitoring Service) from a former architect. I recently watched a debate between a climate scientist and that pheasant-expert-turned-journalist. An audience member asked: "Please could you explain how it is that you are 'right' while all climate scientists are 'wrong'?" He could not. I almost felt sorry for him. I know that he has lectured publicly on scientific heresy. I think that he wants to be Galileo. Contrary to the beliefs of some contrarians, academia welcomes the Galileos and encourages scepticism. It wants its hypotheses robustly tested precisely because it wants to pass those tests. Its stern system of peer review is judicious and conscientious. One more thing is required of academia: to play its role right at the heart of democracy. Being adequately informed is a democratic duty, just as the vote is a democratic right. A misinformed electorate, voting without knowledge, is not a true democracy. Society needs the expertise of academics in the most important issues: climate science above all. A democracy then needs the press to disseminate academia's knowledge and to do so with integrity. But the media's ambition to be entertaining and provocative too often overrules its respect for intellectual rigour. Journalists cannot hold degrees in every subject they report on, but their job is not to claim they know the science better than the experts, or to practise that consummate deception of pretending there is controversy when the consensus is overwhelming. But a controversy is more fun, and the media – skedaddling towards infotainment – is losing sight of the core purpose of its activity: to be a truthful messenger, in this case between the world of academia and the public. I would propose a system of certification for media articles in which there is a clear issue of social responsibility – a kitemark of quality assurance. It would be awarded by teams of academics, and be given to the article, not the journalist, recognising the facts, not the sometimes spurious credibility of being a "personality". It would be awarded when the article is accurate, using reliable sources and peer reviewed studies. There already exists the Climate Science Rapid Response Team, which answers journalists' questions to help them achieve accuracy. The formality of certification is necessary, though, for the reader to know whether to trust an article. Accuracy must not only be achieved, but be seen to have been achieved. The certification should be voluntary. I'm not against entertainment: if someone wants to read nonsense-mongers, let them, but I resent the appearance of parity between two articles on an issue as serious as climate change when one article is actually gibberish masked in pseudoscience and the other is well informed and accurate. When the pheasant expert proffered his climate-heretic views in a hugely popular book, the New Scientist gave his work to a handful of specialists. According to them, the author "completely ignores the mainstream scientific literature", "has a very poor understanding of the core issues", and "introduces confusion". He "cherry-picked evidence to form opinions which are unsupported by the bulk of scientific evidence". His work was "misleading", and an "ideological account". So, no certification there, then. The author has fallen victim to the Galileo fallacy. Just because Galileo was a heretic doesn't make every heretic a Galileo." ----------------------------- links in the article proper @Dale, i'm glad you are trying to get your kid to eat carrots :b: tell him it will make his eye sight excellent/super-human. That trick worked with me, and after a lifetime of reading and staring at computer screens, my eyes are 100% (beyond average). I think my mum used to say 'super-man always eats his vegetables, that is why he is so strong', something like that.
  14. I kind of don't like wifi, i prefer a direct line, but for sure that can be lots of extra work with wiring etc --------------------------------------------------------------------------------- 'Clays in Pacific lavas back drier early Mars': http://www.bbc.co.uk/news/science-environment-19525421 "A study of rocks at an old A-bomb test site in the Pacific has led a team of scientists to conclude that early Mars was not so warm and wet, as many argue. The rocks at Mururoa Atoll in French Polynesia contain clay minerals that look like those seen on the Red Planet. But whereas the Martian clays are taken to be the products of weathering of rocks by liquid water, the atoll's clays have a very different origin. These were precipitated directly from water-rich molten rock as it cooled. The research is published in Nature Geoscience by Prof Alain Meunier from the University of Poitiers, France, and colleagues. It is interesting because it strikes at the heart of the notion that the Red Planet was awash with water, perhaps at its surface, more than 3.75 billion years ago - an idea that has been put forward to explain the great abundance of some clay deposits observed from orbit by satellites. However, the process of clay production at Mururoa, if replicated and widespread on early Mars, would remove the need for such large volumes of water, and with it possibly a more benign environment for life to establish itself on the planet. "Mars was not as warm and wet in its earliest time as some have suggested. I do not believe in an early ocean on Mars," Prof Meunier told BBC News. But [The Mururoa process] explains only the earliest generation of clays on Mars, in the early Noachian period. In later periods, liquid water has existed on Mars' surface; that is undoubtedly the case." The atoll was the site of French nuclear testing from the 1960s to the 1990s. A lot of rock was drilled from the island as part of that programme and is now available for study. Prof Meunier's team shows that clays in these volcanic samples were formed directly in place, in the spaces that sometimes arise between cooling rock crystals. They were not the product of later alteration of the rock through long-term contact with water - the more familiar route to these minerals. "Inside the basaltic rock as the lava is cooling, the crystals are separated sometimes by free spaces in which the residual fluids are concentrated," Prof Meunier explained. "These fluids contain all the components that have not been consumed in the high-temperature crystals like pyroxene, olivine and plagioclase; and among these components, of course, there is water. "As the temperature decreases, these fluids are supersaturated with a lot of phases that consume water and all the remaining elements. And this favours the formation of clay minerals." What is more, when the team examined the infrared reflectance of the Mururoan lavas, they found the signal to be very similar to the observational data obtained by the Mars orbiters that have mapped the Red Planet's clay deposits. Prof John Mustard, of Brown University, Rhodes Island, US, has studied the satellite clay data extensively since its first acquisition in 2005. He said the new research was a welcome addition to the debate about the early environmental conditions on the planet but that he was not convinced the Mururoan lavas could explain the great abundance of clays seen in some regions of the Red Planet. "The question is: how do you generate thick sequences of this stuff? Their model cannot, I don't think, explain a Mawrth Vallis and other thick sections where we can quite clearly demonstrate many hundreds of metres, if not more, of clay formation. Mawrth Vallis has far too much clay to be produced by this process. The amount of clays produced by this degassing process is a relatively small amount." Prof Mustard himself prefers the idea that many of the clays were produced sub-surface at Mars, where warm water could interact with rocks for long periods - such as in hydrothermal systems. Only later were these buried clays excavated into view by impacts or through the erosion of overlying ground by short-lived bursts of flowing surface water. To maintain stable water on the surface of the planet for extended durations would have needed a thick atmosphere - something which is quite hard to reproduce in the climate models of early Mars, explained Prof Mustard. "We make the clear argument that a good chunk of the clays were subsurface," he told BBC News. "I think it's abundantly clear that surface hydrologic systems were probably responsible for a subset of the clay occurrences that we see - but not the dominance. There's very good evidence for there having been interconnected rivers and lakes, but they're very immature. This fluvial renaissance of Mars was very short-lived." The debate is about to get lot more interesting thanks to the imminent first direct measurements of clay minerals on Mars. Nasa has two operational rovers on the planet currently, and both should encounter the deposits. The Opportunity vehicle is heading to the rim of a big crater known as Endeavour where clays have been sighted from orbit. And the Curiosity robot, which has just landed in Gale Crater, will be commanded to drive to the base of a mountain where, again, clays have been detected by satellite." ---------------------------------------------