CCNet

Faculty of Science, Liverpool John Moores University Tel:- +44 (0)151 231 4338 b.j.peiser@ljmu.ac.uk

CCNet 116/06 – 21 July 2006

GLOBAL WARMING DID NOT CAUSE K/T MASS EXTINCTION, NEW STUDY

We examine the role that flood basalt eruptions may have played during times of mass extinction through the release of volcanic gases. We apply this model of flood basalt volcanism to estimate the potential mass of CO2 and SO2 released during formation of the ~65 Ma Deccan province. The impact of volcanic S gas release is likely to be profound at times of flood basalt volcanism. By contrast, the masses and rate of release of CO2 by individual flood basalt eruptions, and especially the resulting predicted increases in atmospheric concentration, are small in comparison to the normal atmospheric reservoir. Such conclusions conflict with studies that invoke climate change through massive CO2 release during flood basalt province formation and, given the relatively small contribution per eruption to contemporaneous atmospheres, processes other than direct release of volcanogenic CO2 now need to be sought to explain these observations.

--Stephen Self et al., Earth and Planetary Science Letters, Article in Press

After the discovery of a large impact crater in Mexico in 1991, the extinction of the dinosaurs appeared to be a closed case. The American micropalaeontologist Gerta Keller, however, disputes this theory, which is the darling of the Dutch geologist Jan Smit.... According to Keller’s scenario, Chicxulub is only one of the many causes weakening flora and fauna in the period leading up to the K/T boundary. Half a million years before the K/T boundary, a series of very large volcano eruptions started in India, which would continue for about one million years. “These eruptions were accompanied by the emission of large amounts of dust and greenhouse gases. As a consequence, the earth heated up again, three to four degrees in the oceans and eight degrees on the land. This heating up was more damaging than the earlier cooling down. Keller argues that only forms of life which could quickly adapt – so-called ecological opportunists – were able to survive.

--Marcel Crok, Natuurwetenschap & Techniek, July-August 2006

Global catastrophes (events that cause the death of more than a quarter of world population) can credibly be caused through either natural events or human activity. It has been argued that space industrialisation generally offers a response to the risks involved by this class of event and should be the key focus of space infrastructure development. Space power has always been argued as the only energy generating option that avoids depletion of non-renewable resources or pollution induced problems—in particular global warming. However, there are many other potential roles for a solar power capability and the infrastructure associated with it can play in the prevention of global catastrophes and this paper examines this wider application. A very preliminary examination indicates the Solar Power Satellite (SPS) infrastructure can also support strategic defence, Near-Earth Object defence, climate modification, and major resource provision. Combined these may give the capability to deal with all the main threats to human civilisation.

--Mark Hempsell, Acta Astronautica, October 2006

(1) GLOBAL WARMING DID NOT CAUSE K/T MASS EXTINCTION, NEW STUDY SHOWS

Stephen Self et al., Earth and Planetary Science Letters, Article in Press, Corrected Proof

(2) ARGUING OVER THE IMPACT: NEW DOUBTS ABOUT THE 65 MILLION YEAR OLD ECOLOGICAL DISASTER

Marcel Crok, Natuurwetenschap & Techniek, July-August 2006

(3) SPACE POWER AS A RESPONSE TO GLOBAL CATASTROPHES

Mark Hempsell, Acta Astronautica, Volume 59, Issue 7 , October 2006, Pages 524-530

(4) GAZA WILL TAKE LONGER THAN LEBANON

Gunnar Heinsohn <gheins@uni-bremen.de>

(5) SPACE AND SOCIETY CONFERENCE: SPACE OPTIONS FOR THE 21ST CENTURY

David Raitt <david.raitt@esa.int>

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(1) GLOBAL WARMING DID NOT CAUSE K/T MASS EXTINCTION, NEW STUDY SHOWS

Earth and Planetary Science Letters, Article in Press, Corrected Proof

http://tinyurl.com/kvlhc

Volatile fluxes during flood basalt eruptions and potential effects on the global environment: A Deccan perspective

Stephen Self a), Mike Widdowson a), 1 Thorvaldur Thordarson b), 2, and Anne. E. Jay a)

a Volcano Dynamics Group, Department of Earth Sciences, The Open University, Milton Keynes, MK7 6AA, UK

b The School of Geosciences, Grant Institute, The King's Buildings, West Mains Road, Edinburgh, EH9 3JW, UK

Abstract

We examine the role that flood basalt eruptions may have played during times of mass extinction through the release of volcanic gases. Continental flood basalt provinces have formed by numerous eruptions over a short period of geologic time, characteristically a few million years. Within this period, a short-lived climactic phase that lasts about 1 Ma typically emplaces a large proportion of the lava volume. This phase consists of a series of huge eruptions, each yielding 10^3–10^4 km^3 of magma. Each eruption lasted on the order of a decade or more, and built an immense p?hoehoe-dominated lava flow field by eruptive activity along fissures tens to hundreds of km long. High fire-fountains, emanating from vents along the fissures, at times sustained eruption columns that lofted gas and ash into the upper troposphere and lower stratosphere while the lava flows covered huge areas. The combination of large eruption magnitudes, maintained high effusion rates during eruptions, and the repeated nature of the characteristic, large-scale eruptive activity occurs in Earth history only during periods of flood basalt volcanism. Based on recent analogs and determination of volatile contents of ancient flood basalt lavas, we estimate that individual eruptions were capable of releasing 10,000 Tg of SO2, resulting in atmospheric loadings of 1000 Tg a^-1 during a sustained decade-long eruptive event. We apply this model of flood basalt volcanism to estimate the potential mass of CO2 and SO2 released during formation of the ~65 Ma Deccan province. The Deccan lava-pile contains the record of hundreds of enormous p?hoehoe flow-fields erupted within a period of about 1 Ma. Consequently, atmospheric perturbations associated with SO2 emissions from just one of these long-lasting eruptions were likely to have been severe, and constantly augmented over a decade or longer. By contrast, the amounts of CO2 released would have been small compared with the mass already present in the atmosphere, and thus much more limited in effect. Individual eruptions were followed by hiatuses of hundreds to thousands of years during which the gas contributions to the atmosphere would be recycled. It is clear that the nature and potential atmospheric impact of a series of huge-volume, repeated, long-term degassing events requires further investigation in conjunction with appropriate climate models.

1. Introduction

Extinction events are important factors in the history of life on Earth, and many studies suggest catastrophic causes for at least some major mass extinctions. Two types of catastrophic event have been invoked: major impacts by asteroids or comets [1] and episodes of continental flood basalt volcanism [2]. As an example of the first cause, the end-Cretaceous (65 Myr) mass extinction has been correlated with the impact of a 10-km-diameter asteroid with Earth, e.g. [3], which undoubtedly would have had severe environmental consequences [4]. However, apart from that example, convincing evidence of impacts has yet to be found at the times of other major extinction events [5]. In support of the second cause, the apparent coincidence flood basalts volcanism such as that of the Deccan province (India) with the end-Cretaceous mass extinction, the Siberian flood basalt province with the severe end-Permian extinction at 250 Ma ago, and the Central Atlantic Magmatic Province with the end-Triassic extinction event [6] and [7], all suggest that flood basalt eruptions may have significantly contributed to a number of global biotic crises. Several studies have compared the dates of extinction events of various magnitudes with the timing of flood basalt episodes and found strong correlations that support a possible cause-and-effect connection (e.g., [8], [9] and [10]). Thus, extreme events of both terrestrial and extraterrestrial origin may be responsible for many of the ‘punctuation marks’ in the history of life on Earth [11], [12], [13], [14] and [15].

Based on recent analog eruptive activity [16], and determination of volatile contents of ancient flood basalt lavas, it is estimated that individual eruptions were capable of releasing on the order 10,000 Tg of SO2 [17] and [18]. This could have resulted in a sustained atmospheric loading of 1000 Tg yr1 over a 10-yr-long eruption duration, assuming constant effusion rates. Such fluxes of S gas are enormous when compared to even the largest historic eruption, and the impact upon the atmosphere and climate are likely to have been significant.

Here we examine the role that flood basalt eruptions might have played during times of mass extinction, highlighting the Deccan volcanism that occurred at the time of the 65 Myr mass extinction event. We restrict this study to subaerial flood basalt eruptions, and consider only the potential amounts of sulphur (S), as its common gas sulphur dioxide (SO2), and carbon dioxide (CO2) that would have been released to the atmosphere. Estimates of how flood basalt volcanism might affect the atmosphere, climate, and hence the global environment are presented and these general considerations are applied to the Deccan lava succession. We do not include discussion of any explosive activity that may have accompanied, or was associated with, the eruption of the Deccan lavas (e.g., [19] and [20]), apart from that which occurred at the vents. Nevertheless, it is clear that such explosive activity could have significantly augmented the delivery of gases and ash to higher levels of the atmosphere. The aim of this work, therefore, is to provide key information and estimates that will better inform modeling of atmospheric effects, and enable the development of improved simulations of the climatic and environmental impact of flood basalt volcanism [21].

[...]

6. Conclusions

Most flood basalt provinces largely consist of tholeiitic basalt, and the work reviewed herein indicates that most tholeiitic fissure basalt eruptions have similar degassing characteristics. We might assume that flood basalt eruptions follow the same degassing pattern, with at least 75% of the burden of dissolved magmatic S and CO2 released at the vents. In the future it will become increasingly important to determine the volumes erupted in individual flood basalt eruptions if we are to be able to improve on the first-order estimates of gas release outlined here; such information is currently unknown for provinces older than the Columbia River basalts. In this context, knowledge of the length of inter-eruption hiatuses will also become important.

The impact of volcanic S gas release is likely to be profound at times of flood basalt volcanism. By contrast, the masses and rate of release of CO2 by individual flood basalt eruptions, and especially the resulting predicted increases in atmospheric concentration, are small in comparison to the normal atmospheric reservoir; in effect, a typical flood-basalt event might contribute only 11,100–1400 Tg of CO2 over a period of decades. Moreover, whilst the amount of CO2 in atmosphere now is ~3 × 10^6 Tg it was perhaps double this amount at the end-Cretaceous, thus making it even less likely that Deccan-derived volcanic CO2 (or, indeed by other flood basalt provinces erupted during the Phanerozoic) had a direct effect on contemporaneous global warming [40] and [76]. Furthermore, given that flood basalt eruptions were probably spaced many hundreds (at the very least) to thousands of years apart, there would have been ample time to equilibrate this relatively small extra mass of volcanic CO2 within natural short term reservoirs. Conversely, biota affected by the deleterious consequences of sulphate aerosols and S deposition may not have been able to fully recover during these hiatuses. Such conclusions conflict with studies that invoke climate change through massive CO2 release during flood basalt province formation [77] and [78] and, given the relatively small contribution per eruption to contemporaneous atmospheres, processes other than direct release of volcanogenic CO2 now need to be sought to explain these observations.

Regarding the S gases emitted, flood basalt magmas appear to be able to release about 5–7 Tg of SO2 gas per cubic kilometer of lava upon eruption. It is likely during a period of flood basalt volcanism, such as the Deccan, that individual eruptions of 5000 km^3 of lava could release up to 35,000 Tg of SO2. Such masses would be emitted during decade-long eruptions at rates of 3500 Tg yr^-1 for a decade, or 350 Tg yr^-1 over a century. An event like this would be followed by a non-eruptive hiatus, during which biota and climate may begin to recover toward pre-eruptive conditions. Repeated eruptions of this magnitude may well have prevented a complete recovery.

Over the whole period of flood basalt province generation, immense amounts of S gases (mainly as SO2) and other species (e.g., halogens) will be released to the atmosphere on a geologically frequent, but possibly random, basis. This scenario is incomparable in scale to volcanic gas releases at any other times in Earth history. The SO2 would have formed considerable amounts of sulphate aerosols that lasted for a long time and certainly, at least as long as the eruptions persisted. Again, the predicted mass of atmospheric aerosols appears to be unprecedented at any other time in Earth history and its effects require testing with climate and atmospheric models appropriate for the geological era during which the flood volcanism was occurring. Many interesting questions remain to be tackled, including issues such as: “Will volcanic plumes rise higher or lower for a given set of paleo-atmospheric conditions?”; and “What would be the fate of SO2 emissions in a Late Cretaceous atmosphere?” Modelling of dense tropospheric and stratospheric aerosol clouds, and their effects on atmospheric dynamics and chemistry applicable to the scenarios documented in this paper, is now urgently required.

FULL PAPER at http://tinyurl.com/kvlhc

doi:10.1016/j.epsl.2006.05.041

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(2) ARGUING OVER THE IMPACT: NEW DOUBTS ABOUT THE 65 MILLION YEAR OLD ECOLOGICAL DISASTER

Natuurwetenschap & Techniek, July-August 2006

By Marcel Crok

“The simple story of a meteorite that hits the earth and at once wipes out the dinosaurs is great for the cover of Science, but is not consistent with field observations,” Dr Markus Harting, a German geochemist who recently joined the University of Utrecht, states.

Strong evidence in favour of such a meteorite impact was a thin layer of sediment with a relatively high concentration of iridium, shocked minerals, and glass spherules (so-called tektites), which has been found in deposits around the world. The heavy metal iridium occurs in much higher concentrations in meteorites than at the earth’s crust.

“After the discovery of the meteorite crater on the Mexican peninsula of Yucatan in 1991, most researchers thought there was sufficient proof, and the impact theory soon became conventional wisdom. By now it seems that the theory is correct mostly because it is conventional wisdom. It all went too quickly and researchers therefore ignore that there are many gaps in the argumentation.”

Harting was a student of Prof. Doris Stueben in Karlsruhe, who is also a strong opponent of the impact theory. In addition, he worked for half a year in the research group of Gerta Keller, professor in palaeontology at Princeton University. Keller is the world’s best-known opponent of the impact theory, and thus, the adversary of Prof. Jan Smit of the Free University in Amsterdam, who achieved international fame for his research on the meteorite impact and its consequences.

Through the telephone, Keller actually goes one step further. “I believe that organisms would have become extinct anyway, even without an impact. The fauna was already extremely stressed at the end of the Cretaceous. The impact was the straw that broke the camel’s back.”

Most researchers still think this is nonsense. They say that almost everything suggests that the transition from Cretaceous to Tertiary actually occurred very suddenly, and that about sixty to seventy per cent of all organisms became extinct within a period of hundreds or thousands of years (the geological equivalent of a blink of the eye). Moreover, the Cretaceous/Tertiary (K/T) boundary coincides exactly with the cosmic impact in Chixculub, named after the Mexican village that is now located near the centre of the crater.

Censorship

Social anthropologist Benny Peiser (Liverpool John Moores University) states that “Smit and Keller are the two most salient researchers in the K/T debate; they are provocative and often appear in the media. But it is certainly not only an argument between these two. It is a debate between researchers who cling to the idea that changes occur gradually and researchers who are convinced by the evidence for the mass extinction due to an impact.” Ten years ago Peiser initiated the electronic newsletter CCNet, which mostly deals with climate change, but also covers the K/T debate.

“In 1980 the American journal Science published an article by Nobel prize winner Luis Alvarez on the impact hypothesis. At that time the crater had not been discovered yet. However, since then opponents of the impact theory have been systematically barred by Science. I am strongly opposed to such ‘censorship’. This is why CCNet provides much coverage of the K/T debate, and why we offer Keller and her supporters a forum to express their views in addition to their scientific publications.”

Peiser indicates that many scientific controversies are barely noticed. “This one receives so much media attention because it deals with the extinction of dinosaurs, the largest ever animals on earth. The public is fascinated by this. But it is not a major debate in terms of money or manpower. Climate change research annually receives two to three billion dollars in the United States. Thousands of researchers work on this. Perhaps only one hundred researchers around the world really specialize in the K/T boundary.”

Peiser believes that it is nearly impossible for outsiders to evaluate the arguments of specialists. He may be right about this. If you try to go more deeply into this subject, you soon feel yourself going back and forth between the two sides, and the latest person you talked to always seems to be right.

But should we conclude that conventional wisdom should be discarded? Jan Smit seems to be primarily fed up with the debate with Keller. “I have collected an enormous amount of evidence from around the world to complete the picture. As a result, it annoys me that Keller only presents evidence from locations that are relatively close to the crater, such as North East Mexico, Texas, Belize and Guatemala. These areas became very unstable as a result of the impact and the sediments in these areas are consequently very complicated and therefore difficult to interpret. The situation is clearer further away from the crater, but Keller refuses to accept this.”

Deccan Traps

In the case of controversies, it is advisable to look for aspects on which the opponents agree. Keller acknowledges the existence of the Chicxulub crater and the occurrence of a mass extinction of organisms around the K/T boundary, but that is about it. She actually believes that the cosmic impact at Chicxulub does not coincide with the K/T boundary, but occurred in Mexico 300,000 years earlier.

Keller thinks that the layer of iridium, which can be found around the world in oceanic sediments, must be the result of a second impact, which occurred 300,000 years after Chicxulub. Why, then, do we fail to find iridium from this impact? Keller: “The impact near Chicxulub must have been from a comet consisting largely of ice.”

Many researchers believe it is improbable that the two impacts occurred so close to each other, for an asteroid or comet of this size is estimated to hit the earth once every 35 million years on average. But it is not completely impossible. Two large craters, the Popigai crater (diameter of 100 kilometres) in Siberia and the Chesapeake crater (90 kilometres) near the coast of Maryland, have been discovered, both of which date from around 35 million years ago.

According to Keller’s scenario, Chicxulub is only one of the many causes weakening flora and fauna in the period leading up to the K/T boundary. Keller: “In addition, climate changes and volcanism played a large part. It was warm during Cretaceous, and the poles were free of ice. During the last few millions of years of Cretaceous, temperatures dropped considerably. This favoured the ocean’s biodiversity, but the dinosaurs on the land started to struggle as it became drier. The number of dinosaur species decreased.”

Half a million years before the K/T boundary, a series of very large volcano eruptions started in India, which would continue for about one million years. In an area the size of France, about two to three million cubic kilometres of basalt surfaced as lava. This caused the formation of the so-called Deccan traps, a mountain range that still exists in North West India. “These eruptions were accompanied by the emission of large amounts of dust and greenhouse gases. As a consequence, the earth heated up again, three to four degrees in the oceans and eight degrees on the land. This heating up was more damaging than the earlier cooling down. Species tend to be more sensitive to heat than cold. Due to the stress, some species experience dwarfism, reproduce quicker and have shorter life spans.”

Keller argues that only forms of life which could quickly adapt – so-called ecological opportunists – were able to survive. Keller herself specializes in foraminifers, single-celled organisms in seas and oceans. “Planktonic foraminifers are most sensitive to climate change. Prior to the K/T boundary the specialised tropical and subtropical species were particularly weakened. Two thirds of all planktonic foraminifer species became extinct as a result. One third of the species consisted of ecological opportunists. They survived for at least another 100,000 years in the Tertiary.” Keller believes that almost all scientists agree with this. “Maybe Jan Smit doubts it, but this insight is, on the whole, generally accepted.”

But maybe Keller is bluffing. At least, Dr Robert Speijer, like Keller a micropalaeontologist, disagrees. The Dutchman, who has been affiliated with the Catholic University Leuven for three years now, conducted research on the K/T boundary in Tunisia, in an area which is a former sea. “If you look at the sediments in Tunisia, you see one very clear transition at the K/T boundary, which only has a thickness of millimetres or centimetres. Below the boundary you find large amounts of diversely composed foraminifers; above it these amounts decrease dramatically, by a factor of one hundred, and the diversity is minimal. To me this is indisputable evidence of a sudden catastrophe which caused a mass extinction.”

Speijer blames Keller for approaching the data too qualitatively. “Qualitatively the picture will always be muddy. You are looking at a thin layer which used to be the bottom of the sea. Animals disturb the seafloor, and storms and streams also transport foraminifers to other places. So, you will always find foraminifers in the sediments above the K/T boundary, even though they had actually already become extinct. On a centimetre to decimetre scale, you cannot take the occurrence of microfossils too literally, but this is exactly what Keller does.”

Vredefort

Speijer thinks it is nonsense to argue that the impact theory became conventional wisdom too quickly. He still remembers the vehement arguments of palaeontologists in the eighties against the impact theory of Luis Alvaraz and Jan Smit. “During the previous 150 years palaeontologists followed Darwin and Lyell in believing that evolutionary change always occurs slowly. Then Alvarez and Smit told us that meteorites and asteroids can significantly accelerate evolution. In the eighties, publications appeared regularly in Nature and Science discussing the link between extinctions and meteorite impacts. The discovery and dating of the Chicxulub crater considerably reduced the scepticism among palaeontologists.”

“I feel there is a good balance now,” Speijer continues, “The K/T boundary is linked to Chicxulub, but other periods of mass extinctions, such as the transition from the Permian to Triassic, are not generally attributed to meteorite impacts. Changes tend to happen gradually, but impacts are part of the picture.”

The impact crater in Chicxulub is, with its diameter of about 180 kilometers, the third largest discovered on earth. A bit larger are the craters in Sudbury in Canada (about 200 kilometres) and Vredefort in South Africa (about 250 kilometres). But these craters are more than two billion years old.

Given the dimensions of the crater, the amount of iridium and model calculations, we can estimate that a meteorite with a diameter of about ten kilometres and a velocity of 18 kilometres per second (65,000 kilometres per hour) fell down 65 million years ago. The meteorite landed in a shallow sea.

“What happened in the first second after the impact can only be approximately calculated by modellers,” as Jan Smit states while he starts an animation on his computer. The simulation resembles a drop falling in the water. “The impactor at first causes a hole with a depth of twenty kilometres. Then the earth rebounds. Modellers have to assume an ideal fluid to make the calculations manageable.”

The top kilometres of the earth’s surface melt as a result of the meteorite’s pressure. This creates small glass spherules, so-called tektites, which are launched in the air, and which have been found as far away as 7000 kilometres from the impact, for example in Spain. “The impacting object itself then evaporates completely. The subsequent huge explosion can only go in one direction, namely, into the atmosphere. The temperature probably increased to 80,000 degrees. According to the American modeller Jay Melosh, the particles in the centre of the pyroclastic flow had enough speed to be ejected into space – the earth’s escape velocity is eleven kilometres per second.”

“The pyroclastic flow then expands very rapidly, and as with rain clouds, this leads to condensation. At first the gases condensate into small liquid drops, but as soon as the pyroclastic flow cools down further, olivine and clinopyroxene crystals are formed. You find this material all over the world.”

The same pyroclastic flow also contains iridium, high concentrations of which are lacking at the earth’s surface, but are present in meteorites. Before the impact hypothesis, researchers believed that this iridium must have been belched by volcanoes. Nowadays nobody doubts that the iridium originates from a meteorite. “My point in the discussions with Keller is that, if you are far away enough from the crater – so that there is no interference from the landslides and tsunamis which must have occurred at that time – you consistently observe an clear and unambiguous pattern of sediments in the oceans: a clay layer full of iridium and short on foraminifers, which therefore suggests extinction coinciding with the K/T boundary.”

“Keller, however, believes that the iridium layer is the result of what we can call the ‘mystery impact’ and that Chicxulub occurred 300,000 years earlier. I can show you tens of examples of sediment cores in which you can see the iridium layer but absolutely nothing 300,000 years earlier – which we can verify relatively easily assuming typical sedimentation rates of two to four centimetres per thousand years. This is very improbable for a crater with a 180 kilometres diameter. Such a crater would leave behind material all over the world.”

Tsunamis

Keller’s group, however, has strong indications that there must have been some time between Chicxulub and the thin iridium layer. They believe that Smit ignores this evidence. Harting explains: “In North East Mexico, about 1000 kilometres from the crater, the K/T boundary is exposed in various locations. Both Smit and Keller – and myself – have done research there. This area used to be located in the Gulf of Mexico, in rather shallow water. What do we find? A package of sediments of eight to twelve meters, with a layer of glass spherules at the bottom, and the iridium layer all the way on top. My chemical analyses demonstrate that the glass spherules originate from Chicxulub. On top of it we find regular sediment layers. It clearly took a considerable amount of time for these sediments to form: approximately 300,000 years.”

Harting conducted chemical analyses of each layer, and provides a plausible reconstruction. “At the bottom we find the original glass spherules. These are still in a perfect state, as they were quickly covered at the time and have therefore been well conserved. On top of it are layers with and without glass spherules. These spherules also originate from Chicxulub, but have clearly been eroded. At this time the Sierra Madre Oriental mountain range was formed. With each uplift, earth layers with glass spherules were exposed. Thus, these spherules were transported by rivers to the Gulf of Mexico thousands of years after the impact.”

It seems impossible to argue with this, but Smit at the Free University is totally unimpressed. He argues that Harting and Keller completely misunderstand the area’s sedimentology. “ I don’t deny that there is a thick package of sediments between the glass spherules and the iridium layer, but dispute that these are ‘regular’ sediments. We know from the recent tsunami in Indonesia that this is a sort of low and high tide movement rather than a tidal wave. The water moves in one direction for about twenty minutes, and then again in the opposite direction for twenty minutes. Probably as many as eight or nine of such tidal movements occurred in the Gulf of Mexico at that time. You also notice ripples in the layers which indicate strong flows.”

Thus, Smit believes that the whole package of sediments was deposited there within hours or days. “The glass spherules are all over the place. So I don’t at all believe Harting’s claim that there are layers without any glass spherules.”

On this point, Smit receives support from the German geologist Dr Peter Schulte of the University of Erlangen. Schulte plays an interesting role in this debate, because he is actually a ‘defector’. Like Harting, he was a PhD student of Stinnesbeck in Karlsruhe. He worked for several months in Mexico and Texas and did a short internship with Keller. But he disagreed fundamentally with Keller and terminated their collaboration. On the phone, he is relatively gentle: “The collaboration was unsustainable. Keller consistently made changes to my articles and she ignored my data.”

Schulte, who has continued his K/T research during the last years, thinks there were many landslides on the bottom of the sea around the Gulf of Mexico at that time, as a result of which the layer with glass spherules was folded like a tablecloth. “If you then look at a cross section of one location, you will see several layers. But you should not look so locally; you must consider the evidence from localities further away from the Gulf of Mexico, for instance the numerous Ocean Drilling Project localities all over the world, where generally only one layer of spherules with Iridium is present exactly at the K/T boundary. If you do this, you can only conclude that there were landslides in the Gulf of Mexico area.”

Furthermore, Schulte believes that it is very unlikely that the glass spherules could reach the sea from the Sierra Madre Oriental in Mexico after a period of 300.000 years. “The spherules decompose and erode very quickly on land. It is much more plausible that the mm-sized spherules rapidly fell on the sea-floor, where they were covered later by the much finer-grained clay sediments that include the iridium. This explains the occurrence of iridium above the layer with spherules and argues against an additional impact event at the K/T boundary besides Chicxulub.”

Harting, however, regards the analysis by Smit and Schulte as hardly scientific. “I also looked at the sand composition in the various layers. You only find a single grain size, and I don’t think this is consistent with a tsunami. Look at Indonesia. There you find sand, mud, stones, all mixed together.”

In addition, Harting finds holes that suggest habitation by, for example, crabs. But Smit and Schulte argue that Harting cannot provide more than one picture, and invite him to provide more evidence from northeastern Mexico. According to Keller Smit ignores the evidence: “evidence of burrows by crabs, worms and other sea creatures have been documented in several discrete layers within the so-called tsunami deposits of Smit for ten years. Smit has consistently ignored this evidence. These creatures lived on the sea floor during times of normal marine sedimentation, then were wiped out by mass flows of sediments only to recolonize the sea floor thereafter. The presence of these burrows effectively rules out a tsunami.”

Yaxcopoil

In order to end this ‘it does/it doesn’t’ game, drillings were done in the crater itself in 2001, near Yaxcopoil. However, this project also led to serious tensions. Harting accuses Smit of violating the initial agreement (that the core would stay in Mexico) by taking back the crucial part of the core – a layer of 55 cm in which the impact breccia with some glass spherules is at the bottom and the K/T boundary at the top – to Amsterdam.

Then it took months before Smit sent the samples to laboratories around the world. Nature suggested that Smit should have acted sooner. Smit still gets furious when reminded of the Nature piece. “It is full of mistakes and unjustified accusations. The Mexicans had created chaos, and also released the core much too late.”

Instead of clarifying matters, this project fuelled the controversy. Keller and her collaborator Dr. Thierry Adatte, a mineralogist from the University of Neuchatel, Switzerland, analysed the samples provided by Smit and concluded that the 55 cm layer contains five thin layers of glauconite. Keller: “Glauconite is a green mineral that forms over tens of thousands of years around small particles in gently agitated waters that prevents the accumulation of other sediments. There presence therefore indicates long-term deposition. Between the layers of glauconite there are regular carbonate sediments, which represent periods of normal marine sedimentation. The planktic foraminifera in these carbonate layers, the paleomagnetic signals and the carbon isotope signals all indicate that these marine carbonates were deposited during the last 300,000 years before the mass extinction. Therefore, the interval between the Chicxulub impact breccia and the K/T boundary in the crater are also separated by about 300,000 years, similar to the sections in NE Mexico.”

According to Smit, however, the glauconite can also come from the glass spherules. “These can be transformed into glauconite over time.” But according to Keller here again, Smit ignores evidence. “The clay alterations resulting from impact glass have very different geochemical signals from those of glauconite and spherules do not transform into glauconite.”

However, an even stronger argument has developed over the presence of foraminifers in the 55 cm core. Keller has published a picture of her sample next to pictures of foraminifers. She believes that the layer contains various foraminifers from Cretaceous. Smit is really furious about this, because he believes that these are simply dolomite crystals. “A very ordinary type of crystal, which makes up half of Spain.”

Keller mentions on the phone that two of Smit’s ‘friends’, Michèle Carron from Switzerland and José Antonio Arz from Spain (who also received samples from Smit), have confirmed the presence of foraminifers.

Arz notifies by e-mail that he has indeed found foraminifers, but that these have been ‘reworked’. “Some of them are perhaps twenty million years older and must therefore have ended up in the core as a result of redeposition.” This is why he supports Smit.

In principle, Caron does so too, but she hints on the phone that she no longer understands Smit’s attitude. “He was here in March and we discussed the foraminifers for a day. He confirmed at the time my conclusion that there were actually foraminifers, but he has retracted this again later and now insists that they are crystals.”

Smit demands on CCNet that Keller makes her samples available to Caron, so that she can provide a second opinion. Keller, however, does not respond. When asked, Keller notes: “Arz has samples from exactly the same layer as mine. So I don’t understand what the sharing of my samples can add. But my samples are actually available. I don’t have them here at Princeton; they are already in Switzerland with my colleague Thierry Adatte in Neuchâtel.”

Smit is surprised when he hears this. And when Caron hears about it from Natuurwetenschap & Techniek, she immediately sends an e-mail to Adatte. But ten days later she still has no reply. Adatte apologizes on the phone: “Busy, busy and I was in the US for a conference.” But the impression remains that Adatte is also not very keen to release the samples. “I am actually not quite sure if I have these specific samples. I will also first ask Keller if it is okay.” The decision follows a week later: Keller and Adatte do not make the samples available after all.

Paradigm

Observer Benny Peiser, who facilitates the debate on his newsletter CCNet, believes that Smit and Keller’s formulations are sometimes ‘unfortunate’, but doesn’t think their behaviour inhibits scientific progress. “I don’t have a problem with a debate. This is, after all, how science works.”

Peiser doesn’t expect the feud between Smit and Keller to end soon. “Don’t forget that Keller has been a gradualist for twenty years. She is convinced that changes occur gradually as a result of climate change and volcanism. Scientists are often very reluctant to discard their paradigm. The same applies, of course, to Smit, who is so closely tied to the impact theory that there is almost no point of return for him any longer.”

Peiser believes that Keller’s case has become weaker in recent years. “But personally I don’t care who is right. Keller is very active and constantly presents new results. Smit mostly reacts. Even if she isn’t right, it is still important that she points out gaps in the impact theory.”

He considers the probability that Keller will find a second crater very small. “But it is not impossible, and she will have won the debate if it happens.”

Keller, by the way, says that she will not be looking for the crater herself. “This is not my specialization.” She thinks the crater must be located somewhere in the Indian Ocean.

Speijer: “Well, then we are back at the starting point. In the 1980s, scientists also speculated about craters on the bottom of the ocean, which have slid underneath continents by now and are, therefore, no longer visible.”

Smit is currently not doing any research on the K/T boundary. But he does want to go to Indonesia to see the impact of the tsunami on sediments there. Smit also recently thought of a new idea regarding mass extinctions. “There have been five periods of mass extinctions. Only one of these can be attributed to a meteorite impact. However, in all cases the earth was warm, there were no ice caps, and the climate had been constant for a relatively long period of time. Maybe evolution is ‘lulled to sleep’ in these circumstances, and species are subsequently unable to adapt to sudden events such as a meteorite, methane eruptions, volcanism or whatever else. I therefore suspect that a meteorite impact at this very moment would not result in a mass extinction. Species can migrate and in this way adapt to climate changes.”

Speijer, however, is sceptical: “A warm earth was the rule during 90 per cent of the last 540 million years. So this idea is difficult to prove.”

Keller does not appreciate this idea either. “It is utter nonsense. The five major mass extinctions are associated with complex and varied climate regimes, including glaciation. This overly simplistic idea that all are related to warm climate and good times that makes creatures forget how to adapt to stress has no more scientific basis – than calling foraminiferal shells crystals.”

(Translation from Dutch: Pieter van Houten)

=============

(3) SPACE POWER AS A RESPONSE TO GLOBAL CATASTROPHES

Acta Astronautica, Volume 59, Issue 7 , October 2006, Pages 524-530

http://tinyurl.com/sycza

Mark Hempsell

a) University of Bristol, Queens Building, University Walk, Bristol BS8 1TR, UK

Abstract

[...]

4. Conclusions

The assessment of the various options is preliminary and not comprehensive. It does, however, give an indication of the possibilities that would become available if an SPS capability on the scale of the NASA reference system were to be implemented. The conclusion can be drawn that, by serendipity, if mankind can generate power from space on an economic basis then other capabilities and options to address global catastrophe events would be viable.

Table 2 summarises the discussion in the paper and shows that all the systems considered can be constructed from elements that match the reference SPS element size. It follows that the individual elements of the supporting infrastructure would also be adequate for their construction. The overall system size (and by inference the supporting infrastructure capability) are also generally comparable with the reference SPS system of 60 SPS with the exception of systems designed to address global warming which need to be on a considerably larger scale.

In addition to the aspects of size and supporting infrastructure capability in many cases the SPS would also develop some, or all, of the technologies needed for the concept.

While technical feasibility may be demonstrated by the SPS, the financing is far more problematic. The considerable difference for most of these concepts is that, unlike the SPS, they are not commercial and would not generate revenue to pay for their construction and maintenance. Mautner concluded an L1 solar parasol would cost in the order $100 billion to 1 trillion [38], and other proposals will all be in that order. There must be some doubt as to whether systems like the solar reflectors would ever get built given that they have no application except in some global catastrophe situations which happen on average every thousand years. However, microwave warming requires no extra investment and thus would be available as an option.

So, while not only the space response to global scale threats to mankind, space power generation is also one of the most important. This is not only because of the already widely discussed impact on energy generation and global warming, it is also because of the flexible response it provides to a wider range of threats, and also because in establishing a space power system other spin-off capabilities are gained, which also add to the response options available when threats materialise. It is concluded that despite the preliminary nature of this examination the role of SPS in general global catastrophe management is worthy of further detailed attention.

FULL PAPER at http://tinyurl.com/sycza

doi:10.1016/j.actaastro.2006.04.001

======== LETTERS ========

(4) GAZA WILL TAKE LONGER THAN LEBANON

Gunnar Heinsohn <gheins@uni-bremen.de>, 20 July 2006

A Muslim woman praising her son’s martyrdom in front of TV cameras usually has resort to more boys at home. Rare, however, is the mother who wants her only son to be lured into the order of suicide attackers.

The first type of mother belongs to Hamas in Gaza where every woman has an average of six children. Fifteen years ago, it was even eight. The more prudent mother resides in Lebanon where birth rate fell below net reproduction in 2005. With an average of 1.95 – only slightly superseded in the Shiite community – it trails the United States’ total fertility rate of 2.1.

Hamas is a movement. Hezbollah is an army. For Gaza’s superfluous offspring, war offers an appropriate option because it can provide every male with either victory or a hero’s death – as Thomas Hobbes cynically but correctly observed in England’s youth-bulge-driven civil wars of 1642 to 1651. The mature soldiers of Hezbollah, however, are positioned in a system of ranks, promotions and pension funds. They raise their arms if ordered so. Yet, few of them will harbor an urge to get to the frontline or even make it to paradise prematurely.

Because Hezbollah’s Iranian paymaster added a nuclear arms program to its purpose of Israel’s annihilation, Hezbollah’s most recent attack on the Jewish state was not shrugged off or met with a team of behind the scene negotiators. It was answered professionally. The sea, land and air supply lines for more Iranian and Syrian weapons reaching Hezbollah were cut off, and the radars were blinded to start the wearisome aerial elimination of hundreds of hardened missile sites. A quiet northern glacis may help the tiny Jewish state on the day the showdown with Iran can no longer be avoided. Under more than 3.000 sorties of Israel’s bombers some 300 Lebanese civilians lost their lives, every single one a tragedy. And yet, is their a case in the history of aerial warfare with a lower load of collateral damage?

Though Hezbollah is an army, it still tries to present itself as the movement it used to be in the 1980s. Between 1975 and 1990, some 150.000 Lebanese slaughter each other in a hideous civil war. In a comparative internecine killing in the US with a population one hundred times bigger than Lebanon, the death toll would have reached 15 million. It is the fear of reigniting Lebanon’s devastating civil war that has, for one and a half decades, blinded the politicians in Beirut, Jerusalem, Washington and at New York’s UN Plaza. Because of this fear Ehud Barak retreated from Lebanon in 2000 without destroying the still manageable proportions of Hezbollah’s arsenal which, then, quickly grew to 12.000 missiles now raining on Israel. Because of this fear, everybody expected a renewal of bloodshed when Syria’s “peacekeepers” were forced out of Lebanon in 2005. Because of this fear, the country’s legitimate government is afraid to take on the Iranian puppet on its own soil. And it is still the same fear that, today, prophesizes another outbreak of Lebanon’s plague.

Yet, was the bloodshed of 1975 to 1990 really due to pious massacres? Did the small country go through a religious war? It is true that fife Muslim and six Christian communities went against each other. Yet, these denominations existed before and after the killings. Not much love was lost between them before 1975 or after 1990. Yet, they got along.

However, there was in motion one factor before 1975 that did not re-emerge after the peace was sealed fifteen years later. A Lebanese women reaching procreation age between 1950 and 1975 gave birth to an average six children, sometimes closer to seven and sometimes closer to five. It was Lebanon’s youth bulge - 30-40% of the male population in the age bracket 15 to 29 – that carried out the monstrous mutual culling. Hezbollah’s sheikh Nasrallah, born in 1960, grew up as one of nine siblings. For fifteen years, Lebanon’s young males acted like today’s Gazans who would plunge even more frequently into Fatah-Hamas shootouts if there were no “guilty” Jews around on whom to blame their unrealizable ambitions.

As early as 1995, Lebanon’s total fertility rate had dropped from 6 to 2.8. The decisive cause of the mutual slaughter, thus, was no longer procured. That is why, after Hezbollah’s defeat, its militias can effectively be disarmed by an international force. Of course, there will be some skirmishes. Yet, the movement of angry young males to feed another civil war will not be available again. The “Arab Switzerland” may well return to its traditional position.

Because Jerusalem did not understand the long gone causes of its neighbour’s civil war it lost six years in which it would have been possible to nib Hezbollah’s armament in the bud. It pays dearly now. Of course, the world public would have turned against Israel’s Jews and not against its mortal enemies. Yet it would not only have been the right thing to do. It would have saved a lot of life too. Instead, Israel’s leaders embraced Arafat in the Oslo peace process. Soon after, feeling betrayed and enraged, they have the bullets and blown up buses of the Second Intifada in their faces.

What had happened? In the Norwegian year of hope 1995, Israel, for the last time, nearly matched the number of Palestinian males between 15 and 29 years of age (610,000 against 690.000). Yet, in 2005, 1,1 million Palestinian males under the age of 15 are prepared for battle against 640.000 Jewish boys. Israel is no longer a David merely against the Pan-Islamic Goliath but even on its own turf.

Peace would first and foremost have required demographic disarmament on the Palestinian side. Yet, another decade went by in which, through UNRWA, the world community put every child born in Gaza on the international dole. Whilst other terror stricken Arab nations returned to calm after they had retreated from six to less than two children per woman – examples given, Algeria to 1.9 and Tunisia even to 1.7 – Gaza’s delivery clinics continued to work at full capacity with hardly anybody providing careers for their able bodied output

Who – like for South Lebanon – now demands an international peace force for Gaza too, will only see progress if simultaneously its total fertility rate is brought down to Lebanese or Tunisian levels. Yet, even if anyone would succeed with such a policy the boys under fifteen growing up with two or three brothers right now, will still turn into angry young men that look for their fight to pick.

Since it is not Israel but the pool of disposable males that lies at the core of the Islamist problem, Israel is in no position to solve it. However, the country has always alleviated this problem in its own surroundings because it does not approach the enemy with random massacres but with targeted killings. Therefore, under all major bloody conflicts since 1960, the Israeli-Palestinian strife ranks – with less than 8.000 dead - so far down at position 46.

In Algeria, however, exploding from 6 to 26 million inhabitants in the half century from 1951 to 1991, nobody could seriously blame the mutual bloodletting between good Muslims and extreme ones on any Jew. Because in that Maghreb state both sides acted without any restraint, more than 150.000 corpses lined the road in just one decade.

It gets dangerous for Israel when its outspoken enemies blame it for the Muslim wars. The country is in mortal danger, however, when even in the West major powers seriously believe that harmony can be achieved by letting down that brave country. In the end one would have sacrificed the Jews only to be exposed to butcheries à la Algérienne between the youth bulges of “liberated” Palestine.

----------

Gunnar Heisohn is Director of the Raphael Lempkin Research Institute on Xenophobia and Genocide, University of Bremen, Germany

============

(5) SPACE AND SOCIETY CONFERENCE: SPACE OPTIONS FOR THE 21ST CENTURY

David Raitt <david.raitt@esa.int>

Dear Colleague,

You are cordially invited to participate in the 2nd Space and Society Conference “Space Options for the 21st Century”, which will be held at ESTEC, Noordwijk, The Netherlands from 27 February – 1 March 2007.

The first announcement and call for papers can be found on the European Space Agency's Conference Web site: http://www.congrex.nl/06a12/

We would be grateful if you would forward this announcement to any colleagues you believe might be interested to also attend.

With kind regards,

The Conference Secretariat

E-mail: Esa.Conference.Bureau@esa.int

****************************

ESA Conference Bureau

European Space Agency - ESA/ESTEC

Postbus 299, 2200 AG Noordwijk, The Netherlands

Telephone: +31 71 565 5005

Fax: +31 71 565 5658

Email: esa.conference.bureau@esa.int

CCNet is a scholarly electronic network edited by Benny Peiser. To subscribe, send an e-mail to listserver@livjm.ac.uk (“subscribe cambridge-conference”). Information circulated on this network is for scholarly and educational use only. The attached information may not be copied or reproduced for any other purposes without prior permission of the copyright holders. DISCLAIMER: The opinions, beliefs and viewpoints expressed in the articles and texts and in other CCNet contributions do not necessarily reflect the opinions, beliefs and viewpoints of the editor.

http://www.staff.livjm.ac.uk/spsbpeis/