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.

The Antarctic Centennial Oscillation: A Natural Paleoclimate Cycle in the Southern Hemisphere That Influences Global Temperature

by W.J. Davis et al., January 8, 2018 in Climate

We report a previously-unexplored natural temperature cycle recorded in ice cores from Antarctica—the Antarctic Centennial Oscillation (ACO)—that has oscillated for at least the last 226 millennia. Here we document the properties of the ACO and provide an initial assessment of its role in global climate.

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New Study Identifies Thermometer for the Past Global Ocean

by UC San Diego, January 4, 2018

There is a new way to measure the average temperature of the ocean thanks to researchers at Scripps Institution of Oceanography at the University of California San Diego. In an article published in the Jan. 4, 2018, issue of the journal Nature, geoscientist Jeff Severinghaus and colleagues at Scripps Oceanography and institutions in Switzerland and Japan detailed their ground-breaking approach.

Study: Climate models underestimate cooling effect of daily cloud cycle

by Princeton University, January 10, 2018 in WUWT

Princeton University researchers have found that the climate models scientists use to project future conditions on our planet underestimate the cooling effect that clouds have on a daily — and even hourly — basis, particularly over land.

The researchers report in the journal Nature Communications Dec. 22 that models tend to factor in too much of the sun’s daily heat, which results in warmer, drier conditions than might actually occur. The researchers found that inaccuracies in accounting for the diurnal, or daily, cloud cycle did not seem to invalidate climate projections, but they did increase the margin of error for a crucial tool scientists use to understand how climate change will affect us.


by Dr David Whitehouse, January 17, 2018 in GWPF

It is clear that 2017 was a very warm year. Tomorrow, NOAA, NASA and the UK Met Office will announce by how much. It won’t be a record-breaker, but it will be in the top five, and that has already started comments about why it has been so hot. After all, the record-setting El Niño temperatures of the 2015-16 are over – so why did it remain so hot? The reason, according to some, is clear: the resurgence of global warming. The year 2017 is the hottest non-El Niño year ever and therefore signifies a dramatic increase of global warming after 20-years or so when the global temperature hasn’t done very much.

Earth’s Rotation Is Mysteriously Slowing Down: Experts Predict Uptick In 2018 Earthquakes

by Tevor Nace, November 20, 2017 in WhoaScience

Scientists have found strong evidence that 2018 will see a big uptick in the number of large earthquakes globally. Earth’s rotation, as with many things, is cyclical, slowing down by a few milliseconds per day then speeding up again.

You and I will never notice this very slight variation in the rotational speed of Earth. However, we will certainly notice the result, an increase in the number of severe earthquakes.

Geophysicists are able to measure the rotational speed of Earth extremely precisely, calculating slight variations on the order of milliseconds. Now, scientists believe a slowdown of the Earth’s rotation is the link to an observed cyclical increase in earthquakes.

Seafloor Volcano Pulses May Alter Climate

by Columbia University, February 5, 2015

Vast ranges of volcanoes hidden under the oceans are presumed by scientists to be the gentle giants of the planet, oozing lava at slow, steady rates along mid-ocean ridges. But a new study shows that they flare up on strikingly regular cycles, ranging from two weeks to 100,000 years—and, that they erupt almost exclusively during the first six months of each year. The pulses—apparently tied to short- and long-term changes in earth’s orbit, and to sea levels–may help trigger natural climate swings. Scientists have already speculated that volcanic cycles on land emitting large amounts of carbon dioxide might influence climate; but up to now there was no evidence from submarine volcanoes. The findings suggest that models of earth’s natural climate dynamics, and by extension human-influenced climate change, may have to be adjusted

Further proof El Ninos are fueled by deep-sea geological heat flow

by Janes E Kamis, January, 27 in CliateChangeDispatch

The 2014-2017 El Nino “warm blob” was likely created, maintained, and partially recharged on two separate occasions by massive pulses of super-heated and chemically charged seawater from deep-sea geological features in the western North Pacific Ocean. This strongly supports the theory all El Ninos are naturally occurring and geological in origin. Climate change / global warming had nothing to do with generating, rewarming, intensifying, or increasing the frequency of the 2014-2017 El Nino or any previous El Nino.

If proven correct, this would revolutionize climatology and key aspects of many interrelated sciences such as oceanography, marine biology, glaciology, biogeochemistry, and most importantly meteorology. Information supporting a geological origin of El Ninos is diverse, reliable, and can be placed into five general categories as follows: (…)

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