Category Archives: End of year summaries, general musings

Field studies – real or virtual?

Every evening’s TV schedules include either an ad for some kind of ‘virtual reality’ (VR) device or a ‘techie’ programme in which one appears. As well as massively multiplayer online role-playing games, commercial VR offers 3-D encounters with charging rhinoceroses, surfing, wingsuit flying and other ‘experiences’ that are either life threatening or viciously expensive. Second Life, the online virtual world (but not yet compatible with VR goggles), appeared as long ago as 2003 and at present has about a million regular users and many more have passed through its portal, eventually to tire of its cheesiness. Yet, Second Life no longer seems to be a topic of normal conversation; maybe aficionados don’t go out very often. The development software, the speed and resolution of computers, the peripheral technologies and the visual quality of immersive VR seem to be following something like Moore’s law – the observation that the number of transistors in a dense integrated circuit doubles approximately every two years. And VR gaming is clearly very profitable with revenues likely to rise from about US$17 million in 2014 to over US$ 20 billion by 2020.

Douglas McCauley writes in Science (Insights 20 October 2017) about the potential of digital games and simulation for expanding the reach of STEM education, particularly in his own field ecology (McCauley, D.J. 2017. Digital nature: Are field trips a thing of the past? Science, v.  359, p. 298-300; doi: 10.1126/science.aao1919). His view is partly positive, as they match the thirst for armchair experiences and the growing digital expertise of the billion or more gamers and many more whose culture is dominated by electronic media, skewed strongly to the under-24s. For instance, children in the US spend on average 7 hours per day online, but only 4 to 7 minutes of unstructured outdoor play. There are obvious opportunities to familiarise and enthuse young people with the staggering richness of the natural world, which none of us will ever be able to witness first hand. At a time when the UK National Trust reports, for instance, that only a third of British children can recognise a magpie (a distinctive and common European member of the crow family) whereas 9 out of 10 easily recognise a Dalek alien cyborg, there is clearly a need. Sixty years ago David Attenborough’s early monochrome Zoo Quest series on BBC TV definitely drew me into natural science as it did millions of others, and I for one am deeply grateful for his then somewhat awkward efforts. So it would be stupid to condemn the potential of VR and more plain-vanilla gaming methods as they could do much the same and probably a great deal more. But can it really teach the field skills needed by any potential observational scientist rather than just make people more interested?

McCauley is less certain on that front, and so am I. Studies have shown that virtual field trip participants perform no better than their peers who engaged only in conventional illustrated lectures. ‘Immersive’ experiences can simulate some, but not all aspects of real terrain, ecosystems and geological features.  My own geological ventures have involved a ‘virtual’ aspect provided by remote sensing and image interpretation. Those now pretty aged technologies show ‘the big picture’ – with some zoom-in capacity – and provide insights into regional and, with Google Earth, local geological structures and relationships. By capturing imagery outside the humanly visible wavelength range they add a great deal about rock composition that would otherwise require large sample collections, petrographic interpretation of thin sections and some basic geochemistry. A stereoscopic 3-D view and the use of terrain in creating perspective oblique images also permit estimates of dip and strike of strata. But it is all a bit inhuman and alien, much the same as ‘doing’ geology on Mars without the opportunity to behave as a curious being would if actually on the surface. Any field scientist has real experience imprinted for years in much the same way as would her hunter-gatherer forbears, while it has been shown that virtual experiences may persist for a mere few weeks. My view is that often uncomfortable, total immersion in field reality, literally step-by-step and day after day fosters continual reflection during and for a long time after the experience. Much of science in general is about ‘mulling over’ observations at every level of detail; the more detail and the more repetition the deeper the insight and the more profound the breaks through.

As higher education continues along its path of commodification the more supposedly ‘immersive’ virtual experiences are likely to supplant field work, largely for cost reasons – both for students and institutions. In my former institution, to which I am still tenuously attached, a decision was taken 17 years ago to make residential field studies optional, and in 2011 to abandon them almost entirely in favour of ‘virtual’ experiences of one kind or another. The results have been dramatic: enrollment in geoscientific courses has fallen to a third of the pre-2000 level; retention has declined by up to 10% and pass rates have dropped significantly. The bottom line is that what we used to call Earth sciences has become increasingly marginalised as regards the range of courses on offer.

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Human genetic archaeology round-up

English: Vindija cave near Varazdin in Croatia...

Vindija cave near Varazdin in Croatia. (credit: Wikipedia)

Work on Neanderthal genomes continues, as expected. The latest news comes from remains of a Croatian female, whose genome has been determined by a team led by members of the Max Planck Institute for Evolutionary Anthropology in Leipzig (Prüfer, K. and 35 others 2017. A high-coverage Neandertal genome from Vindija Cave in Croatia. Science, online; doi:10.1126/science.aao1887). Her full genome is of higher quality than those previously published for Neanderthals. Dated at around 52 ka, her genetics is likely to be closer to those who mated with the ancestors of modern Eurasians. Kay Prüfer and his colleagues suggest that Neanderthals passed on to modern Eurasians genes associated with plasma levels of LDL cholesterol and vitamin D (mainly produced by skin exposure to sunlight, Vitamin D is essential for healthy bones and supports the immune system), together with risk factors for eating disorders, accumulation of visceral fat, rheumatoid arthritis and schizophrenia. Two other interesting possibilities stem from reconsidering genetic data from other Neanderthals, in the light of the new Croatian analysis. Ancestors of an older Neanderthal (122 ka) from the Altai region of Siberia had interbred with genetically modern humans as long ago as 130 ka. Yet the genomes of the Altai and Croatian Neanderthals are surprisingly similar, suggesting that both lived in isolated small groups around three thousand strong (Gibbons, A. 2017. Neanderthal genome reveals greater legacy in the living. Science, v. 358 p. 21).

Also published on-line by Science is a study of the genomes of 7 individual anatomically modern humans from KwaZulu-Natal in South Africa (Schlebusch, C.M. and 11 others 2017. Southern African ancient genomes estimate modern human divergence to 350,000 to 260,000 years ago. Science online; doi: 10.1126/science.aao6266). They are three 2000 year-old hunter-gatherers (probably San) and four Iron Age farmers, similar to modern Bantu speakers, from 300 to 500 years ago. Although genomes from modern Khoe-San suggest up to 30% admixture from East Africans and Eurasians, comparison between the two ancient groups suggest a very old divergence among African anatomically modern human (AMH) populations, of the order of 350 to 260 ka ago. This is long before the remains from Ethiopia, widely accepted as the oldest known AMH (190 ka), but roughly the same as recently described fossils from Jebel Irhoud in Morocco (325 to 286 ka) reckoned to be early AMH. The Moroccan humans and now the genetic analysis from much more recent South African skeletons point to a pan-African early evolution of modern people rather than some kind of ‘cradle of humanity’.

English: Man in an Upper Paleolithic burial in...

Adult male in an Upper Paleolithic (28-30 ka) burial at Sunghir, Russia. (credit: Wikipedia)

More ancient AMH hunter-gatherers (~28 to 30 ka) occur at Sunghir, about 200 km east of Moscow, a settlement that includes several burials – one of which contained a boy and a girl – many with abundant, ornate grave goods. It seems likely that all the interred individuals were related and so an excellent target for DNA analysis. Four individuals with roughly the same 14C age did yield enough for genome sequencing (Sikora, M. and 26 others 2017. Science, online; doi: 10.1126/science.aao1807). It turned out from their mtDNA that none were more closely related than first-cousins or great-grandchildren. The data suggested a relatively small breeding population (~300) that avoided inbreeding and its often negative consequences, possibly through exogamy (a wide mating network) as practiced by living hunter-gatherers. Remarkably, the data also hinted at relationship with earlier (36 ka) individuals from Kostenki about 300 km to the south-west. DNA from several Siberian Neanderthal individuals do suggest that inbreeding had been an issue. Had it been widespread among Neanderthals – risky to infer from such scanty information – that may account for their lack of competitiveness with AMH and eventual demise.

Some observations on scientific publication

For most scientists research brings many pleasures: exercising curiosity and ingenuity; the moment of discovery, sometimes an esprit de corps; showing that you were right, and so on. Anthropologists might say that it is a form of playfulness, the ‘scientific method’ being the rules of the game. Telling people about your results at conferences also has its bright moments: showing off; making new acquaintances and renewing old ones; a wider esprit de corps; globetrotting, all expenses paid. Communicating data and discussing results formally before that part of the academic world that you inhabit is a pain by comparison, even for the most gifted writer.  Have all avenues of enquiry and interpretation been exhausted? Is your paper a model of clarity, and will/can anyone read it? Is what you have to recount actually new and/or important? Have you missed something that has already been published? Have you committed plagiarism unconsciously. Are your references bang up to date? The anonymous peer-review system can be merciless, and so can journal editors. Writing up and awaiting reviews are among the most stressful periods in the professional lives of most researchers, because so many boxes have to be ticked to glide effortlessly into print.

The greatest of all literary bugbears is tailoring the style of your list of references to that of the target journal. Very, very occasionally the publisher will employ kindly sub-editors who make sure that all is well in this the most arcane of all academic rituals. The problem is that every academic publishing house and even different journals that each produces have subtly different rules for references cited, in the text and in the list at the end. There are so many permutations and combinations: a comma before the year; v. before volume number, including the issue or not, bold or plain font; journal name in full or one of several kinds of abbreviation; each author’s initials separated by a space or not (the former for the Journal of Geology if you have been wondering – ‘Their given names in full are separated by a space, so it is only polite’!). And there is much, much more in each journal’s ‘Information for Authors’. Quanmin Guo of the University of Birmingham (Correspondence, Nature, v. 540 22/29 December 2016, p. 525) makes the obvious point that every journal should conform to a uniform style – within vividly distinctive bindings what is the need for arcane house rules?

But there is another, more serious grouse about the vast majority of journals. If your institution or you as an individual cannot afford to subscribe to a journal you will inevitably come up against the ‘paywall’ when you try to read an article on line ($10 – 50 per article) even at a time when well-heeled academics are paying for their papers to be open-access (in most cases still behind the paywall for 6 months following publication). The irony is that less well-off researchers also cannot afford to make their work available to all.  Alexandra Elbakyan of Alamaty, Kazakhstan, set out to circumvent the paywall barrier to scholarly exchange, and succeeded in the foundation of Sci-Hub (Van Noorden, R. 2016. Paper pirate. Nature, v. 540, p. 512-513), which hosts about 60 million papers and encompassed about 3% of all PDF downloads in the last year (simply by pasting in a paper’s DOI. Alexandra has been widely praised and thanked, served with a writ for breach of copyright (by Elsevier), had Sci-Hub shut down by order of a US judge (there are proxies), and is currently incommunicado (except for encrypted e-mail) for fear of a demand for multi-million dollar damages. Chances are that she has opened a floodgate to future universal open access. In the meantime, unless I am hopelessly mistaken, there is a perfectly legal work around for you to get must-read papers shortly after they appear at no cost. Email the corresponding author (usually in the free online Abstract in a journals latest issue list of contents) and ask for an offprint in the form of a PDF ‘for the purpose of scholarly exchange’.

Geoscience academic under threat

While she was US Secretary of State from 2009 to 2013, Hilary Clinton the 2016 Democrat candidate for presidential office habitually used her private email server to send and receive messages, both personal and concerning affairs of state. She did not activate a state.gov email account for the official stuff, saying that it was ‘for convenience’ as her Blackberry smartphone could only access on account. More than 30 thousand undeleted e-mails were hacked by ‘persons unknown’ and appeared on Wikileaks in early 2016, with more in late October 2016, to become one of several issues central to the 2016 US presidential campaign. This practice was twice exonerated by the FBI, despite her account proving to be insecure and the risk to state secrets.

Hans Thybo, President of the European Geophysical Union and a widely esteemed professor of seismology at the University of Copenhagen, was not so lucky. He was fired by the University authorities, allegedly for using his private email account for work-related issues and advising a postdoctoral fellow that criticising the University’s management was ‘legitimate’. More than 1000 academic colleagues have petitioned the University of Copenhagen to reverse its decision and reinstate Thybo, and his case was central to the lead editorial A creeping corporate culture in Nature of 15 December 2016.

Anyone connected for more than a few years with academic life in probably every university on the planet will be conscious of the spread of a culture of bureaucratic control, corporatism and commodification in what formerly were largely self-governing institutions of higher education and research. The trend is in line with increasing, omnidirectional economic pressures stemming from the aftermath of the 2007-8 global financial crisis. But it is not entirely new. My own experience suggests it is partly a logical outcome of leading academics becoming increasingly prone to saying ‘Yes’; at best simply disengaging from dispute with a growing managerial caste within education and research, at worst by opportunistically joining it. A serious disjuncture has developed between teachers and researchers and the managers and business administrators in institutions of higher education. Symptomatic of this kind of schism was the recent passing of a motion of no confidence in the Vice Chancellors Executive of Britain’s Open University by its unionised academic and academic-related staff, following disastrous bungling of a new means of tuition of its entirely non-residential undergraduates in the current academic year. Those who were to implement the measures were inadequately consulted by the leading managers, most of whom had little experience of how the OU had functioned successfully since it received its Charter in 1969.

In Britain, checks and balances on the requirements of management and faculty historically centred on their Senate, once the primary academic authority of universities, in which all members of both academic and non-academic sectors freely debated and passed judgement on new directions and the abandonment of practices that had been found wanting. In most institutions, the Senate has been reduced since the mid 1980s to a mere fraction of staff, who, after nomination, are elected by the various components of the institution, together with unelected, ex officio, members of senior management. In practice, Senates now generally act as a ‘rubber stamp’ for decisions of the top echelons, much in the manner of business corporations.

Part of the new culture attempts to regulate electronic communications. An example of such an IT regulation states that the institution ‘… may monitor all data, systems and network traffic at any time …’, i.e. it claims ownership of work-related communication. No wonder Hans Thybo fell foul of his university. Should outside pressure persuade the authorities of the University of Copenhagen to reinstate him, that would be a significant blow against what has become an unwholesome aspect of learning and scholarship.

A challenge to the concept of species

Comparison of DNA from ancient hominin fossils with that obtained from a broad spectrum of living people showed that on the road out of Africa in the last 130 thousand years some anatomically modern humans successfully interbred with Neanderthals and Denisovans to produce fertile offspring. All non-African people contain a trace of those liaisons and include fertile hybrids in their ancestry, whereas Africans do not. Using quick, low-cost and sensitive genomic analyses these discoveries made similar searches for hybridisation among other supposedly distinct species a popular and fruitful line of research (Pennisi, E. 2016. Shaking up the tree of life. Science, v. 354, p. 817-820; doi: 10.1126/science.354.6314.817). They also challenge the long-held view that individual species are incapable of fertile interbreeding with others. Yet fertile hybrids have long been known among plants and butterflies without recourse to genomics. Now that it is a basic tool, it has been shown that up to 10% of known plant species have arisen from hybrids and examples are quickly being found among birds, insects, fish and mammals, including the famous Galapagos finches. Hybridisation introduces genetic variation more quickly than does mutation, potentially a major advantage in adaptive radiation.

Page from Darwin's notebooks around July 1837 ...

Page from Darwin’s notebooks around July 1837 showing his first sketch of an evolutionary tree. (credit: Wikipedia)

Of course, the concept of ‘species’ is arbitrarily based on biological ‘form and function’, and in the same fashion as discoveries about epigenetics have shown genetic determinism to have an air of dogma, so hybridisation suggests that a ‘web’ is more apt as shorthand for the progress of evolution than is Darwin’s ‘tree’ or even a tangled ‘bush’. Another welcome outcome spurred by the pioneers of hominin comparative genetics is a powerful challenge to the dominant philosophies of reductionism and dualism among scientists; legacies of René Descartes bound up with the ‘scientific method’ – especially among physical scientists – and ideas such as ‘nature versus nurture’. A major revolution is in progress, from which the seekers for a Theory of Everything, from quantum mechanists through particle physicists to cosmologists need to draw some sharp and perhaps embarrassing lessons.

It is appropriate that the driving agency lies within anthropology, and thrilling too, for everyone can quickly learn a new way of approaching the world by contemplating their own origins. They would be hard-pressed to do that by pondering on the early nanoseconds of the cosmos …

The nearest Earth-like planet

What could be more exciting for exobiologists and planetary scientists than to discover that a nearby star is orbited by a planet approximately the same mass as the Earth that may support liquid water: a world in the ‘Goldilocks zone’? It seems that Proxima Centauri, the Sun’s closest companion star (4.2 light years distant), might have such a planet (Anglada-Escudé, G. And 30 others 2016. A terrestrial planet candidate in a temperate orbit around Proxima Centauri. Nature, v. 536, p. 437-440).  It is one of 34 candidates found to date with various levels of likelihood for having the potential to produce life and support it. To fit the bill a planet first has to orbit a star at a distance where the stellar energy output is unlikely to vapourise any surface water yet is sufficient to keep it at a temperature above freezing point, i.e. the ‘Goldilocks’ or circumstellar habitable zone is closer to a cool star than to a hot one. Note that the liquid-water criterion requires that the planet also has an atmosphere with sufficient pressure to maintain liquid water. It also needs to have a mass close to that of the Earth (between 0.1 to 5 Earth masses) and a similar density, i.e. a candidate needs to be dominated by silicates so that it has a solid surface rather than being made mainly of gases and liquids.

The location of Alpha Centauri A and B, Proxim...

The location of Alpha Centauri A and B, Proxima Centauri and the Sun in the Hertzsprung-Russell (HR) diagram. (credit: Wikipedia)

Proxima Centauri b, as the planet is called, was not discovered by the Kepler space telescope using the transit method (drops in a star’s brightness as a planet transits across its disk) but by terrestrial telescopes that measure the Doppler shifts in starlight as it wobbles because of the gravitational affect of an orbiting planet. As well as being close, Proxima Centauri is much smaller than the Sun so such effects are more pronounced, especially by planets orbiting close to it. The planet that has excited great interest has an orbital period of only 11.2 Earth days so is much closer to its star and may have a surface temperature (without any greenhouse effect) of 234 K (21 degrees less than that of Earth). The wobble suggests a mass and radius are likely to be 1.3  and between 0.8 to 1.4 times those of Earth, respectively. So Proxima Centauri b is probably a silicate-rich world. But, of course, such limited information gives no guarantee whatever of the presence of liquid water and an atmosphere that can support it. Neither is it possible to suggest a day length. In fact, such a close orbit may have resulted in the planet tidally locked in synchrony with its orbit, in the manner of the Moon showing only one face to the Earth. Moreover, its star is a red dwarf and is known to produce a prodigious X-ray flux, frequent flares and probably a stream of energetic particles, from which only a planet with a magnetic field is shielded. All red dwarfs seem to have such characteristics, and the list of possible Earth-like planets show them to be the most common hosts.

It is too early to get overexcited as technologies for astronomical detection of atmospheres and surface composition are about a decade off at the earliest. Being so close makes it tempting for some space agency to plan sending tiny probes (around 1 gram) using a laser propulsion system that is under development. Anything as substantial as existing planetary probes and certainly a crewed mission is unthinkable with current propulsion systems – a one-way trip of 80 thousand years and stupendous amounts of fuel.

China’s legendary great flood did happen

The Biblical Flood is one of several legendary catastrophes that over the millennia have made their way into popular mythology. Indeed, Baron Georges Cuvier explained his stratigraphy of the Paris Basin and fossil evidence for extinctions of animals as the results of repeated inundations. His opinions and those of other scientists of the catastrophist school reflect the philosophical transition that began with the Enlightenment of the 18th century: curiosity and observation set against medieval dogma. It seems that transition is incomplete as there are still people who seek remains of Noah’s Ark and propose alien beings as the constructors of the huge geoglyphs of the Nazka Desert in Peru. On the other hand, Walter Pitman – one of the pioneers of plate tectonics – and his colleague William Ryan sought a rational explanation for the Flood, based in part on a more detailed description of a flodd in the Near East in one of the oldest written documents, the Epic of Gilgamesh (~2150-1400 BCE). In 1996 they published a hypothesis that such flood legends may have arisen from oral accounts of the flooding of the previously cut-off Black Sea basin through the Bosphorus as global sea level rose about 7600 years ago.

Chinese mythology too contains graphic descriptions of catastrophic flooding in the legend of Emperor Yu, first written down at the start of the first millennium BCE. Rather than being a victim or a survivor of catastrophe, Yu is credited with relieving the aftermath of the supposed flood by instigating ingenious systems of dredging and rechanneling the responsible river, and instigating the start of Chinese civilisation and the Xia Dynasty. Such detail conveys a greater air of veracity than a substantial boat containing male and female representatives of all animal species ending up on top of a mountain once Flood waters subsided! Recent research by Quinglong Wu of the School of Archeology at Peking University, together with other Chinese and US colleagues along the Yellow River has nailed the truth of the legend to events in the headwaters of the Yellow River (Wu, Q. and 15 others 2016. Outburst flood at 1920 BCE supports historicity of China’s Great Flood and the Xia dynasty. Science, v. 353, p. 579-582).

Map of the Yellow River

Map of the Yellow River from the Qing Dynasty. (Photo credit: Wikipedia)

The team discovered evidence for a huge landslide in a terrace of the Yellow River where it flows through the Jishi Gorge. Probably dislodged by an earthquake, the slide blocked the gorge so that a large lake formed above it. The lake also left sedimentary evidence on the flanks of the gorge, which suggest that it may have been as much as 200 m deep and impounded 12 to 17 km3 of water. Downstream of the gorge sediments of the Guanting Basin contain chaotic sediments characteristic of outburst floods, probably deposited once the landslide dam was breached. 14C dates of charcoal from the outburst flood sediments give a likely age for the massive event of 1922±28 BCE. Astonishingly, remains of three children from a cave near the Yellow River are buried in the flood deposits and provided an age within error of that of the flood: they were victims. Sediments extending to the coast in the North China Plain are the repositories of much of the archaeological evidence for the evolution of Chinese culture along with signs of rates of sedimentation. The definite signs of a catastrophic flood upstream coincides with the transition from Neolithic to Bronze Age artefacts in the Yellow River flood plain.

Stepping Stones relaunch on-line

In 2000 I was approached by Ian Francis, then a commissioning editor at Blackwell Science if I would like to write a series of news items on advances in Earth Science for the publishers’ new website Earth-Pages. The invitation stemmed from his having read my recently published book Stepping Stones: The Making of Our Home World, which threaded a similar path through developments in the science that I helped to teach through the Open University. Ian’s initiative led to my learning a great deal by sifting through leading scientific journals, which became a weekly discipline. Much of what I commented on covered the eclectic spread of Stepping Stones, but I did not think of authoring a revised edition of the book until just a few years before I retired from the Open University in 2011. As they say; ‘what with one thing or another’ it took me another 7 or 8 years to galvanise myself for such a task. If you would like to have a look at the revised edition, it is now on-line at https://earthstep.wordpress.com/.

The famous 3.6 Ma old hominin footsteps at Laetoli in Tanzania – Stepping Stones emblematic image. (Credit: Mary Leakey)

The famous 3.6 Ma old hominin footsteps at Laetoli in Tanzania – Stepping Stones emblematic image. (Credit: Mary Leakey)

Deciding to produce it in electronic form it occurred to me to make it a possible means of geoscience self-teaching by various devices, such as suggesting key words and phrases to find more in-depth material through a web browser and, equally important, to find useful images. Fifteen years of working on over 800 posts for Earth-Pages and the publications that they were about made revising Stepping Stones a quicker task than I had anticipated. Then it dawned on me that I had written a lot more on various topics for Earth-Pages than I had in the new project. So the Earth-Pages archive is a possibly valuable learning resource, if you can navigate through it, which is not always easy. Being the source for most of the new additions to the book’s Further Reading in, inserting links from each reference to the appropriate post in the Earth-Pages archive was easy.

Oh, and another thing, so few published science authors gain satisfaction from royalties, I decided Stepping Stones v.2.0 should be free!

A ‘proper’ stratigraphic view of the ‘Anthropocene’

Readers may recall my occasional rants over the years against the growing bandwagoning for an  ‘Anthropocene‘ epoch at the top of the stratigraphic column. I , for one, was delighted to find in the latest issue of GSA Today a more sober assessment of the campaign by two stratigraphers who are well placed to have a real say in whether or not the ‘Anthropocene’ is acceptable, one serving on the International Commission on Stratigraphy, the other on the North American Commission on Stratigraphic Nomenclature (Finney, S.C. & Edwards, L.E. 2016. The “Anthropocene” epoch: Scientific decision or political statement? GSA Today, v. 26 (3–4).

Focus on glaciation…and avoid physics envy

About 1.3 billion years ago two small black holes, each weighing in at about 30 solar masses, ran into one another and fused. At that time Earthly life forms had neither mouths nor anuses, nor even a nervous system, and they were not much bigger than a sand grain. The distant collision involved  rapid acceleration of considerable masses. A century ago Albert Einstein predicted that the movement of any matter in the universe should perturb space-time in a wave-like form that travels at the same speed as light. Well, he was right for, at 9:50:45 universal time on 14 September 2015, four exquisitely engineered mirrors deployed in the two set-ups of a Laser Interferometer Gravitational-Wave Observatory (LIGO) in Louisiana and Washington states in the US minutely shuddered, first in the Deep South and 0.007 seconds later in the Pacific Northwest. The signal lasted 0.25 seconds and, when rendered as sound, comprised a sort of chirrup starting at 35 Hz and rising to 250 Hz before an abrupt end. Five months later, and silent internationally shared theoretical verification, the story was released to the back slapping, stamping and pawing the air that we have come to expect from clever, ambitious and persuasive people who have spent a great deal of our money and have something to show for it. So now we know that the universe is probably throbbing – albeit very, very, very quietly – with gravitational waves generated by every single motion that has taken place in the whole of ‘recorded’ history since the Big Bang. Indeed, it is claimed, LIGO-like machines may one day detect the big wave itself if, that is, it hasn’t already passed through the solar system. Recall, 13.7 billion years ago the Big Bang didn’t take much longer than this comparatively mundane collision at 1.3 Ga . Physicists are going to have a lot to ponder on now they have a lever to get yet greater funds. To put all this in perspective, the detected chirrup had been traveling for 1.3 Ga, and so too must the actual place in the universe where it took place: I guess we will never know where it is now or what damage or otherwise may have been visited upon planetary systems in its vicinity, if indeed it had even the slightest recognisable geological or ecological consequence.

So, onto the mundane world of glaciology and climate change.

Tibet is the third greatest repository of glacial ice on the surface of the Earth’s continents. It is the focus of one of the planet’s greatest climatic system, the South Asian. While much of the Plateau hasn’t borne glaciers continuously throughout even the last glacial cycle, it is becoming clear that its western margin has remained cold enough to retain ice throughout an even longer period. In the Kunlun mountains is a 200 km2 ice cap known as the Guliya. At the start of detailed glacial stratigraphic ventures in 1990s, focused mainly on Greenland and Antarctica, analysis of a core from the Guliya ice cap yielded dates extending back to 130 ka, before the start if the last interglacial. This section lies above ice that at the time could not be dated reliably other than to show that it may be older than about 750 ka. This stemmed from its lack of the radioactive 36Cl formed, similarly to 14C, by cosmic-ray interactions with stable 35Cl in atmospheric salt aerosols: such cosmogenic chlorine can be used for radiometric dating of ice younger than 750 ka.

A News Feature in the 29 January issue of Science (Qiu, J. 2016. Tibet’s primeval ice. Science, v. 351, p. 436-439) focused on the preliminary results of an expedition, led by Yao Tandong of the Institute of Tibetan Plateau Research, Beijing and Lonnie Thompson of Ohio State University, Columbus, to drill a further five ice cores at Guliya in September 2015, one of which penetrated ove 300 m of glacial ice. It is now possible to date ice layers back to a million years using argon isotopes. Combined with stable isotope and other measurements through the cores, the dating should provide a huge amount of new information on the evolution of the monsoon, which is currently understood only vaguely. Such information would sharpen models of how the monsoon system works and even hint at how it might change during a period of anthropogenic warming. An estimated 1.4 billion people – a fifth of humanity – who live in the Indian subcontinent, China and SE Asia depend for their food-production on the monsoon.

With less humanitarian urgency but equally fascinating is the discovery that, as well as sea-ice, the central Arctic Ocean once hosted vast ice shelves during the last-but-one glacial episode (Jakobsson, M. and 24 others 2016. Evidence for an ice shelf covering the central Arctic Ocean during the penultimate glaciations. Nature Communications, v. 7, doi:10.1038/ncomms10365. Clues emerged from multibeam sonar bathymetry that created detailed images of topography on the floor of the Arctic Ocean. These revealed sets of parallel ridges on the shallowest parts of the polar basin, thought to have formed when moving ice shelves grounded. The depths of the grooved areas indicate ice thicknesses up to and exceeding 1 km. The grooves look very similar to the large-scale lineaments that formed on the surface of the Canadian Shield when the Laurentide ice sheet ground its way from zones of glacial accumulation. Grounding of an ice shelf would have resulted in its thickening in the upflow direction as a result of plastic deformation of the ice, tending to lock the flow and direct ice escape over the deeper parts of the Arctic basin.

Antarctic Ice Shelf

Antarctic Ice Shelf (credit: Wikipedia)

Back-tracking the grooves defines the ice shelf’s source regions in the northern Canadian islands, north Scandinavia and the lowlands of eastern Siberia as well as regional flow patterns and the extent of floating continental ice. The last is a major surprise: at over 4 million km2 it was four times larger than all modern Antarctic ice shelves. The ice moved to ‘escape’ to the North Atlantic Ocean through the Fram Strait between East Greenland and Svalbard (Spitzbergen). Dating sediment stratigraphy in the grooved areas using magnetic and fossil data shows that the ice shelves existed between 160 and 140 ka during the penultimate glacial maximum. For such a mass of glacial ice to be expelled into the Arctic Ocean implies that a great deal more snow fell on its fringes then than during the last glacial maximum. Another possibility is that the huge mass of floating ice regulated the salinity and density of the upper Atlantic in a different way from the periodic iceberg ‘armadas’ that characterized the last glacial epoch and help account for a whole number of sudden warming and cooling events.

Domack, E. 2016. A great Arctic ice shelf. Nature, v. 530, p. 163-164.