Tous les articles par Alain Préat

Full-time professor at the Free University of Brussels, Belgium • Department of Earth Sciences and Environment Res. Grp. - Biogeochemistry & Modeling of the Earth System Sedimentology & Basin Analysis • Alumnus, Collège des Alumni, Académie Royale de Sciences, des Lettres et des Beaux Arts de Belgique (mars 2013). • Prof. Invited, Université de Mons-Hainaut (2010-present-day) • Prof. Coordinator and invited to the Royal Academy of Sciences of Belgium (Belgian College) (2009- present day) • Prof. partim to the DEA (third cycle) led by the University of Lille (9 universities from 1999 to 2004) - Prof. partim at the University of Paris-Sud/Orsay, European-Socrates Agreement (1995-1998) • Prof. partim at the University of Louvain, Convention ULB-UCL (1993-2000) • Since 2015 : Member of Comité éditorial de la Revue Géologie de la France • Since 2014 : Regular author of texts for ‘la Revue Science et Pseudosciences’ • Many field works (several weeks to 2 months) (Meso- and Paleozoic carbonates, Paleo- to Neoproterozoic carbonates) in Europe, USA (Nevada), Papouasia (Holocene), North Africa (Algeria, Morrocco, Tunisia), West Africa (Gabon, DRC, Congo-Brazzaville, South Africa, Angola), Iraq... Recently : field works (3 to 5 weeks) Congo- Brazzaville 2012, 2015, 2016 (carbonate Neoproterozoic). Degree in geological sciences at the Free University of Brussels (ULB) in 1974, I went to Algeria for two years teaching mining geology at the University of Constantine. Back in Belgium I worked for two years as an expert for the EEC (European Commission), first on the prospecting of Pb and Zn in carbonate environments, then the uranium exploration in Belgium. Then Assistant at ULB, Department of Geology I got the degree of Doctor of Sciences (Geology) in 1985. My thesis, devoted to the study of the Devonian carbonate sedimentology of northern France and southern Belgium, comprised a significant portion of field work whose interpretation and synthesis conducted to the establishment of model of carbonate platforms and ramps with reefal constructions. I then worked for Petrofina SA and shared a little more than two years in Angola as Director of the Research Laboratory of this oil company. The lab included 22 people (micropaleontology, sedimentology, petrophysics). My main activity was to interpret facies reservoirs from drillings in the Cretaceous, sometimes in the Tertiary. I carried out many studies for oil companies operating in this country. I returned to the ULB in 1988 as First Assistant and was appointed Professor in 1990. I carried out various missions for mining companies in Belgium and oil companies abroad and continued research, particularly through projects of the Scientific Research National Funds (FNRS). My research still concerns sedimentology, geochemistry and diagenesis of carbonate rocks which leads me to travel many countries in Europe or outside Europe, North Africa, Papua New Guinea and the USA, to conduct field missions. Since the late 90's, I expanded my field of research in addressing the problem of mass extinctions of organisms from the Upper Devonian series across Euramerica (from North America to Poland) and I also specialized in microbiological and geochemical analyses of ancient carbonate series developing a sustained collaboration with biologists of my university. We are at the origin of a paleoecological model based on the presence of iron-bacterial microfossils, which led me to travel many countries in Europe and North Africa. This model accounts for the red pigmentation of many marble and ornamental stones used in the world. This research also has implications on the emergence of Life from the earliest stages of formation of Earth, as well as in the field of exobiology or extraterrestrial life ... More recently I invested in the study from the Precambrian series of Gabon and Congo. These works with colleagues from BRGM (Orléans) are as much about the academic side (consequences of the appearance of oxygen in the Paleoproterozoic and study of Neoproterozoic glaciations) that the potential applications in reservoir rocks and source rocks of oil (in collaboration with oil companies). Finally I recently established a close collaboration with the Royal Institute of Natural Sciences of Belgium to study the susceptibility magnetic signal from various European Paleozoic series. All these works allowed me to gain a thorough understanding of carbonate rocks (petrology, micropaleontology, geobiology, geochemistry, sequence stratigraphy, diagenesis) as well in Precambrian (2.2 Ga and 0.6 Ga), Paleozoic (from Silurian to Carboniferous) and Mesozoic (Jurassic and Cretaceous) rocks. Recently (2010) I have established a collaboration with Iraqi Kurdistan as part of a government program to boost scientific research in this country. My research led me to publish about 180 papers in international and national journals and presented more than 170 conference papers. I am a holder of eight courses at the ULB (5 mandatory and 3 optional), excursions and field stages, I taught at the third cycle in several French universities and led or co-managed a score of 20 Doctoral (PhD) and Post-doctoral theses and has been the promotor of more than 50 Masters theses.

Claim: Next 10 years critical for achieving climate change goals

by Anthony Watts, April 13, 2007

Carbon dioxide (CO2) and other greenhouse gases in the atmosphere can be reduce in two ways–by cutting our emissions, or by removing it from the atmosphere, for example through plants, the ocean, and soil.

The historic Paris Agreement set a target of limiting future global average temperature increase to well below 2°C and pursue efforts to even further limit the average increase to 1.5°C above pre-industrial levels. Yet the timing and details of these efforts were left to individual countries.

Methane seeps in the Canadian high Arctic

by Geological Society of America, April 13, 2017

in ScienceDaily

Cretaceous climate warming led to a significant methane release from the seafloor, indicating potential for similar destabilization of gas hydrates under modern global warming. A field campaign on the remote Ellef Ringnes Island, Canadian High Arctic, discovered an astounding number of methane seep mounds in Cretaceous age sediments.

Afrique du Sud : les enjeux du gaz de schiste

by Professeur François Lafargue, Avril 2017

in Connaissance des Energies

La puissance économique et industrielle de l’Afrique du Sud classe naturellement ce pays au premier rang des consommateurs d’énergie en Afrique. L’Afrique du Sud consomme 30 % de l’énergie primaire et 37 % de l’électricité produites sur le continent africain. Les fréquents dysfonctionnements des infrastructures d’électricité constatés ces dernières années ont placé la question de l’énergie au centre des débats publics.

Questions on the rate of global carbon dioxide increase

by Robert Balic, April 7, 2017

Its also a stretch to assume perfect correlation of the real values, especially since its claimed that CO2 levels have increased due to human emissions and the latter have been at a steady rate for the last three years. There is also the question of why such a good correlation with SH sea-surface temperatures and not NH, and why should the correlation be so perfect when things like changes in ocean currents should have a large effect on how much is sequestered into the depths of the oceans.

Incredible images show how Newfoundland town is digging itself out of more than two metres of snow

by Caitrin Pilkington, April 6, 2017

Extraordinary images are now coming from the Newfoundland and Labrador town, where the snow is high enough to cover doors and windows completely. More than 135 cm of snow has fallen on the town of Gander, Nfld., over the past week after it was hit with two back-to-back Nor’easters.

To put that precipitation in perspective, Torontonians can expect around 115 cm of snow in an entire year.

First macrobiota biomineralization was environmentally triggered

by Rachel Wood et al., March 29, 2017

All known Ediacaran skeletal biota produced either aragonite or high-Mg calcite: carbonate polymorphs interpreted to have been favoured by ambient seawater chemistry. Indeed all known Ediacaran skeletal taxa were immobile benthos found exclusively in shallow marine carbonate settings. Finally, we note that Ediacaran skeletal taxa are of diverse affinity, and some possessed a non-mineralized, organic, counterpart, as detailed below


The art of green deception . . . about those record temperatures in Antarctica

by Warren Blair, April 7, 2017

The unusually high Esperanza temperature is likely the result of a strong jet stream that brought a strong ridge of high pressure over the Antarctic Peninsula, allowing warm air from South America to push southwards over Antarctica. Antarctic sea ice was at record-highs in 2014 and again in 2015 when modern records were shattered.

La situation énergétique américaine en chiffres

par Connaissances des Energies, 7 avril 2017

L’EIA américaine a publié récemment ses données officielles relatives à la consommation et à la production d’énergie aux États-Unis en 2016. Elle constate entre autres un recul du charbon dans le mix électrique américain. État des lieux.

Énergies fossiles : 81% de la consommation américaine d’énergie

La consommation d’énergie primaire des États-Unis a été quasiment stable en 2016  (+ 0,1% par rapport à 2015). Les énergies fossiles ont encore compté l’an dernier pour près de 81% de cette consommation (contre 86% en 2005). Le pays a consommé davantage de produits pétroliers dans les transports en 2016, de gaz pour la production d’électricité et dans le secteur industriel mais significativement moins de charbon (- 9%) pour la troisième année consécutive.

Influence of high-latitude atmospheric circulation changes on summertime Arctic sea ice

by Q. Ding et al., March 13, 2017, Nature Climate Change

The Arctic has seen rapid sea-ice decline in the past three decades, whilst warming at about twice the global average rate. Yet the relationship between Arctic warming and sea-ice loss is not well understood. Here, we present evidence that trends in summertime atmospheric circulation may have contributed as much as 60% to the September sea-ice extent decline since 1979.

Egalement : Recul de la banquise arctique: 30% à 50% lié à la variabilité naturelle de l’atmosphère

China’s Hunger For Cars

by Dyfed Loesche , 


With soaring car sales in China in mind, U.S. President Donald Trump might want to sway his Chinese counterpart Xi Jinping to grant American manufacturers easy access to the Chinese market. In 2008, sales in China caught up with those in the United States (at 6.7 million units). In 2016, sales stood at a whopping 24.4 million and counting. Sales of cars in other big manufacturing nations are almost stagnant.


Learning from the climate’s history: the Arctic heat waves of the 1930s and 40s

by Dr. Sebastian Lüning and Prof. Fritz Vahrenholt [German text translated/edited by P Gosselin] , April 1, 2017

Now let’s extend the time scale and look back 100 years. What a surprise: In the 1930s and 1940s there were two heat decades in the Arctic which were almost as warm as today (Fig. 2). This is just a small fact that went missing in the WMO press release and in the article.

Global Warming and Hurricanes – NOAA says no measurable effect yet

by Anthony  Watts, April 5, 2017

From NOAA’s Geophysical Fluid Dynamics Laboratory, March  17, 2017

Two frequently asked questions on global warming and hurricanes are the following:

Have humans already caused a detectable increase in Atlantic hurricane activity or global tropical cyclone activity?
What changes in hurricane activity are expected for the late 21st century, given the pronounced global warming scenarios from current IPCC models?

Quelles énergies dans le monde pour 2050 ?

by  Jean-Louis Schilansky, Président du Centre Hydrocarbures Non Conventionnels, 3 Avril 2017

Le début du XXIe siècle connaît une période inédite d’abondance et de diversité énergétique, marquée par d’importantes avancées technologiques dans la production d’énergie. Les développements les plus notables concernent l’essor des énergies renouvelables et des ressources d’hydrocarbures non conventionnels, en particulier de pétrole et de gaz de schiste en Amérique du Nord

When will Earth lose its oceans?

by J.  Lecomte et al., CNRS, December 16, 2013

The natural increase in solar luminosity — a very slow process unrelated to current climate warming — will cause the Earth’s temperatures to rise over the next few hundred million years. This will result in the complete evaporation of the oceans. The first three-dimensional climate model able to simulate the phenomenon predicts that liquid water will disappear on Earth in approximately one billion years, extending previous estimates by several hundred million years.

Jérémy Leconte, Francois Forget, Benjamin Charnay, Robin Wordsworth, Alizée Pottier. Increased insolation threshold for runaway greenhouse processes on Earth-like planetsNature, 2013; 504 (7479): 268 DOI: 10.1038/nature12827


China and Pakistan Join Forces For World’s Biggest Brown Coal Programme

by Dr. Benny Peiser, April 3, 2017

Chinese engineer and inventor Feng Weizhong has an easy ­answer to how China plans to keep slashing coal use and power-­station emissions while relying on coal to provide at least 55 per cent of its massive energy demand for decades to come. The effervescent Professor Feng, who is also general manager of a large Shanghai power plant, explained to The Australian how the country can contrive to do both at the same time. “Simple! It’s clean coal!”

Une mine de charbon allemande bientôt reconvertie en site de stockage ?

by Connaissance des Energies, 22 mars 2017

Des chercheurs allemands étudient la possibilité de transformer dans la région de la Ruhr une mine de charbon en un site de stockage hydroélectrique. En Rhénanie-du-Nord-Westphalie (ouest de l’Allemagne), l’extraction au sein de la mine de charbon de Prosper-Haniel a débuté en 1863. Une procédure de fermeture de cette mine, qui fournit encore près de 2,5 millions de tonnes de charbon par an(1), devrait être engagée fin 2018. Mais l’activité ne devrait pas s’arrêter sur le site : il est prévu que la mine soit transformée en une station de transfert d’énergie par pompage (STEP).