Tous les articles par Alain Préat

Full-time professor at the Free University of Brussels, Belgium apreat@gmail.com apreat@ulb.ac.be • 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). http://www.academieroyale.be/cgi?usr=2a8crwkksq&lg=fr&pag=858&rec=0&frm=0&par=aybabtu&id=4471&flux=8365323 • 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 http://geolfrance.brgm.fr • Since 2014 : Regular author of texts for ‘la Revue Science et Pseudosciences’ http://www.pseudo-sciences.org/ • 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.

Are methane seeps in the Arctic slowing global warming?

by Randall Hayman, May 8, 2017, in Science


Good news about climate change is especially rare in the Arctic. But now comes news that increases in one greenhouse gas—methane—lead to the dramatic decline of another. Research off the coast of Norway’s Svalbard archipelago suggests that where methane gas bubbles up from seafloor seeps, surface waters directly above absorb twice as much carbon dioxide (CO2) as surrounding waters. The findings suggest that methane seeps in isolated spots in the Arctic could lessen the impact of climate change.

A paleo-perspective on ocean heat content: Lessons from the Holocene and Common Era

by Yair Rosenthal et al., January 1, 2017


 

Here we review proxy records of intermediate water temperatures from sediment cores in the equatorial Pacific and northeastern Atlantic Oceans, spanning 10,000 years beyond the instrumental record.

These records suggests that intermediate waters were 1.5–2 °C warmer during the Holocene Thermal Maximum than in the last century.

Intermediate water masses cooled by 0.9 °C from the Medieval Climate Anomaly to the Little Ice Age.

 

Is Murry Salby Right?

by Red Istvan, May 13,2017


The core of Salby’s theory is derived using CO2 data from MLO’s Keeling Curve since 1958, and satellite temperature data since 1979. (His few charts reaching back to 1880 contain acknowledged large uncertainties.) His theory builds off a simple observation, that in ‘official’ estimates of Earth’s carbon cycle budget, anthropogenic CO2 is only a small source compared to large natural sources and sinks.

Shelf sediments reveal climate shifts through the eons

by University of Queensland, May 10, 2017, in DailyScience


Ms Korpanty said global climate underwent significant change about 14 million years ago when the Antarctic ice sheet expanded.

“The new study presents shallow-marine sediment records from the Australian continental shelf, providing the first empirical evidence linking high-altitude cooling around Antarctica to climate change in the subtropics during the Miocene era,” she said.

Earth’s forests just grew 9% in a new satellite survey

by J.F. Bastin et al., May 11, 2017 in ScienceDaily

in Science May 11, 2017

The Age of Exploration may be long past, but even in the 21st century, our maps can still get a major update. Using satellite imagery, a new study has found hidden forests all over the world—almost enough for a second Amazon—in areas with little moisture known as drylands.

 


A new estimate of dryland forests suggests that the global forest cover is at least 9 percent higher than previously thought. The finding will help reduce uncertainties surrounding terrestrial carbon sink estimates.

See also L‘équipe d’un chercheur belge découvre 467 millions d’hectares de forêt passés sous les radars

Dr. Fred Singer on ‘Global Warming Surprises’

by Fred Singer, May 11, 2017


Temp data in dispute can reverse conclusions about human influence on climate.

Exploring some of the intricacies of GW [Global Warming] science can lead to surprising results that have major consequences. In a recent invited talk at the Heartland Institute’s ICCC-12 [Twelfth International Conference on Climate Change], I investigated three important topics:

1. Inconsistencies in the surface temperature record.

2. Their explanation as artifacts arising from the misuse of data.

3. Thereby explaining the failure of IPCC to find credible evidence for anthropogenic global warming (AGW).

S. Fred Singer is professor emeritus at the University of Virginia and a founding director of the Science & Environmental Policy Project; in 2014, after 25 years, he stepped down as president of SEPP.  His specialty is atmospheric and space physics…

Video: analysis of NASA data shows modern temperature trends are not unusual

by Michael Thomas c/o Anthony Watts, May 10, 2017


An important aspect of the climate change debate can be summed up like this: “One position holds that medieval warm temperatures reached levels similar to the late twentieth century and maintained that the LIA was very cold, while another position holds that past variability was less than present extremes and that the temperature rise of recent decades is unmatched”. This video challenges whether the rise of recent decades is unmatched.

Quelles perspectives pour la politique pétrolière américaine ?

by Olivier Appert, Président du Conseil Français de l’Energie

in Connaissance des Energies, 10 mai 2017


Depuis la découverte du colonel Drake en 1859, le pétrole a joué de façon continue un rôle majeur dans la politique économique américaine et sur le plan international, il a été un outil clé du leadership américain. Au fil du temps, cette politique a dû composer avec une modification des rapports de force sur le marché pétrolier. La révolution récente des hydrocarbures non conventionnels a été un game changer majeur. Au fond, la politique pétrolière du nouveau président américain n’est qu’un retour aux sources.