The BBC News over the weekend had one of those hushed thrall like monologues on the subject of supervolcanoes on Mars – in response to a press blurb released on the publication of a paper in the journal Nature – see www.bbc.co.uk/news/science-environment-24392559 and www.bbc.co.uk/news/science-environment-24348673
The reverence and wonderment of the journalist concerned was quite amusing – but he clearly accepted it all without question and even assured us all this paper proved that gases emitted by the hypothetical super volcano had spewed far enough into the sky to create the atmosphere of Mars. The BBC are getting more like Wikipedia by the hour – the place not to go if you want to know the facts.
Actually, the paper and research is rather good, and illustrates how one man noticing an anomaly, and sticking at the problem, can make a big difference. It didn't require a consensus of 95 per cent of anything, just a single brain determined to solve what he saw in images from space of craters in a particular region of Mars. He decided they could not be attributed to asteroid or meteorite strikes, which was the consensus opinion, because they are irregular in shape – and there are several of these crater like depressions. In fact, the term 'depression' is more apt, he decided – and that meant something else was involved. This, we may briefly note, suggests craters are too easily defined as impact related – so are there other anomalies associated with cratering?
The same story is at www.dailymail.co.uk/sciencetech/article-2441761/Did-supervolcanoes-Mars-… .. where you may note a different emphasis, or nuance, on the press release. This link was sent in by Gary and there are some good space shots on view worth looking at just for that. The coverage is quite substantial, and not only that, it has the qualifier, 'could be' attached to it, on several occasions. In other words, the Mail science correspondent was not overawed by the reputation of Nature – which is a good thing. Neither was he critical – which is also a good thing. Gary Gilligan saw this as evidence that Mars was a seething cauldron of fire spitting volcanoes as it churned through space and came close to Earth, and those readers interested in what he has to say can go to www.gks.uk.com/ under section 19, The Egyptian Cobra Goddess Wadjet.
The Mail article begins – Mars may once have been rocked by titanic super volcanic eruptions that would have shaped the planets climate, scientists believe. Looking at the Mail site their science coverage is actually quite good and I have now added this to my list of sites to view on a regular basis, usually once a month as I now have too many to click on to on a weekly basis. The space images were excellent.
The same story is at good old http://phys.org/print299948804.html … which also comes with NASA images of the structures on the surface of Mars. The topography is depicted in colours so a bit of imagination is required. It turns out the researcher was looking at these images, and similar topographical information from NASAs Mars Odyssey, Mars Global Surveyor, and Mars Reconnaissance Orbiter spacecraft and ESAs Mars Express Orbiter. It seems that because a caldera is a depression it can look like a crater – or this is what has been hypothesized. What I found interesting was that there was plenty of evidence of recent volcanoes on Mars but none going back to the early universe period – and this is where the caldera hypothesis has come out trumps. It provides mainstream with the necessary volcanic activity on Mars in the remote past. In addition, the paper also theorises that the magma emitted from the super volcano was loaded with dissolved gases that rose upwards once released, like a bottle of soda that has been shaken (their words) before opening and then bursting out in all directions. The thinking here is that the rapid release of gases would have altered global temperature on Mars, latching on to the idea that greenhouse gases are a warming agent. The depression would have been continued as the caldera subsided, causing the landscape around it to sink at the same time. I'm sure Thunderbolts will have something to say about the cratering – but this is the essence of what has been the big story in this month's Nature journal. The surrounding terrain has been known for impact cratering and the basin concerned naturaly became attached to that kind of interpretation. That is, until the lone researcher saw the anomaly, and kept at it even when others might have abandoned the search for objectivity. Another problem he saw was that he could see no evidence of ejecta – melted glass like shards thrown up by an impact event. He contacted a volcano specialist to seek his opinion and he ended up as the co-author. He said a series of rock ledges in the basin might have been left behind from a lava lake, which had drained, while on the outside of the basin, there are rings of faults and valleys that are similar to those that occur when the ground collapses because of activity below the surface. We may note that none of this precludes a cosmic vector at some stage in the process.