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.

Unanticipated Stability: Latest Polar Conditions Show No Signs Of Global Warming Melting

by P. Gosselin, August 16, 2017 in NoTricksZone


Weather and climate analyst Schneefan here writes of “early frost” in the Arctic and how Greenland snow and ice have grown after being hit by a “snow bomb”. This contradicts the expectations of global warming alarmists.

The polar summer this year appears to have ended prematurely. The mean temperature of the central Arctic above 80°N has remained under the long-term average over the entire summer and even dipped below the freezing point about a week earlier than normal (1958-2002 mean).

Evènements naturels extrêmes : pas d’augmentation

by Uzbek, 7 février 2017, in ClimatoRéalistes


Il se produit en moyenne 300 catastrophes naturelles par an, soit presque une par jour ; nous en sommes informés en temps réel  et la responsabilité du réchauffement est presque systématiquement invoquée. Il se diffuse ainsi dans l’opinion l’idée d’un dérèglement climatique qui irait en s’accentuant sous l’effet du réchauffement. Les différentes sources de données  exploitées dans cet article sont convergentes : il n’y a pas d’augmentation de la fréquence , de l’intensité et de la durée des événements  extrêmes depuis le début de l’ère industrielle, qu’il s’agisse des cyclones et des tempêtes, des inondations, des sécheresses et des vagues de chaleur . Cela est d’ailleurs admis par le GIEC dans son rapport spécial sur les événements extrêmes de 2012, et dans son 5ème rapport d’évaluation de 2013.

Voir également ici, ici et  ici 

Possible hominin footprints from the late Miocene (c. 5.7 Ma) of Crete?

by Gerard D. Gierlinski et al., August 31, 2017 in Proc.Geologist’sAssoc.


We describe late Miocene tetrapod footprints (tracks) from the Trachilos locality in western Crete (Greece), which show hominin-like characteristics. They occur in an emergent horizon within an otherwise marginal marine succession of Messinian age (latest Miocene), dated to approximately 5.7 Ma (million years), just prior to the Messinian Salinity Crisis.

Texas Major Hurricane Intensity Not Related to Gulf Water Temperatures

by Ph.D.  Roy Spencer, August 29th, 2017 in GlobalWarming


As the Houston flood disaster is unfolding, there is considerable debate about whether Hurricane Harvey was influenced by “global warming”. While such an issue matters little to the people of Houston, it does matter for our future infrastructure planning and energy policy.

Let’s review the two basic reasons why the Houston area is experiencing what now looks like a new record amount of total rainfall, at least for a 2-3 day period over an area of tens of thousands of square miles.

Which oil and gas companies are preparing for the future? Executive Summary

by Tarek Soliman et al., November 2019, in CDPinthe pipeline


  • This report introduces CDP’s League Table for oil and gas companies, highlighting company performance across a range of portfolio, emissions and water-related metrics which indicate carbon risk preparedness and highlights earnings risks for oil and gas companies.
  • Highest ranked companies are Statoil, Eni and Total.
  • Lowest ranked companies are Suncor, ExxonMobil and Chevron.

Can Oil Sands Pay Off at Just $50 a Barrel?

by Kevin Orland, August 24, 2017 in BloombergNews


Canada’s tar sands, which contain the planet’s third-largest oil reserves, were a prized possession for global energy companies when crude was trading above $100 a barrel. But since prices fell to $50 in 2015, where they have lingered, Royal Dutch Shell, ConocoPhillips, and Marathon Oil have unloaded their holdings amid concerns that these capital-intensive projects would struggle to turn a profit.

(…) In recent earnings announcements, Suncor and rival Cenovus Energy Inc. said they can now sustain production with oil at $40 a barrel without jeopardizing the dividend they pay shareholders.

Why ‘Hide The Decline’? There Has Been No Net NH Warming Since The 1940s

by Kenneth Richard, August 31, 2017 in NoTricksZone


In the press release for a newly published and controversial  peer-reviewed scientific paper, Australian scientist Dr. Jennifer Marohasy unveiled one of climate science’s better-kept secrets.

She and her colleagues are well aware that the post-1940s Northern Hemisphere (NH)  proxy evidence from tree-rings, bore holes, pollen, etc., consistently fails to affirm sharply rising temperatures from the late 20th century onwards.

Natural Gas Looks Hurricane-Proof, for Now

by Nathaniel Bullard, September 1, 2017 in BloombergView


Since 2005, the U.S. has added more than 120,000 gas wells, mainly in Texas, Pennsylvania, Oklahoma and Colorado. In 2015, there were 555,000 in total.

Those onshore wells have not just made up for declining offshore production, they have handily exceeded it. Offshore gas is now only 4 percent of total U.S. withdrawals. Texas, Pennsylvania, Oklahoma and Colorado are 53 percent of all production.

Evidence for Little Ice Age in Antarctica

by UC Santa Cruz Newscenter, August 31, 2017 in WUWT


Changes in the sources of nitrogen and the composition of the phytoplankton community are more likely to account for the differences seen in the isotope data, Huckstadt said. “It looks more like a shift at the base of the food web, probably related to the transition from the Little Ice Age to current conditions, causing changes in the phytoplankton community,” he said.

See also: “Here we present new data from the Ross Sea, Antarctica, that indicates surface temperatures were ~ 2 °C colder during the LIA, with colder sea surface temperatures in the Southern Ocean and/or increased sea-ice extent, stronger katabatic winds, and decreased snow accumulation.”

A new estimate of biodiversity on Earth

by University of Chicago Press Journals, August 30, 2017 in ScienceDaily


To date, about 1.5 million species have been formally described in the scientific literature, most of them insects. Proportionally, bacteria comprise less than 1% of all described species.

In a new paper published in The Quarterly Review of Biology (September 2017), researchers from the University of Arizona have estimated that there are roughly 2 billion living species on Earth, over a thousand times more than the current number of described species.

The onset of widespread marine red beds and the evolution of ferruginous oceans

by Haijun Song et al., August 2017, in Nature


Banded iron formations were a prevalent feature of marine sedimentation ~3.8–1.8 billion years ago and they provide key evidence for ferruginous oceans. The disappearance of banded iron formations at ~1.8 billion years ago was traditionally taken as evidence for the demise of ferruginous oceans, but recent geochemical studies show that ferruginous conditions persisted throughout the later Precambrian, and were even a feature of Phanerozoic ocean anoxic events.

Soil carbon debt of 12,000 years of human land use

by J. Sanderman et al., July 2017 in PNAS


Human appropriation of land for agriculture has greatly altered the terrestrial carbon balance, creating a large but uncertain car- bon debt in soils. Estimating the size and spatial distribution of soil organic carbon (SOC) loss due to land use and land cover change has been difficult but is a critical step in understand- ing whether SOC sequestration can be an effective climate mitigation strategy.

See also here

Volcanic eruptions drove ancient global warming event

by Marcus Gutjah et al., August 30,  2017 in PhysOrg


A natural global warming event that took place 56 million years ago was triggered almost entirely by volcanic eruptions that occurred as Greenland separated from Europe during the opening of the North Atlantic Ocean,

The amount of carbon released during this time was vast—more than 30 times larger than all the fossil fuels burned to date and equivalent to all the current conventional and unconventional fossil fuel reserves we could feasibly ever extract.” Ridgwell said.

An unexpected finding was that enhanced organic matter burial was important in ultimately sequestering the released carbon and accelerating the recovery of the Earth’s ecosystem without massive extinctions.

See also here

Climate-driven variability in the occurrence of major floods across North America and Europe

by Glenn A. Hodgkins et al., September 2017 in Journal of Hydrology


 

Trends in major-floods from 1204 sites in North America and Europe are assessed.

Trends based on counting exceedances of flood thresholds for groups of gauges.

The number of significant trends was about the number expected due to chance alone.

Changes in the frequency of major floods are dominated by multidecadal variability.

See also here

Texas Major Hurricane Intensity Not Related to Gulf Water Temperatures

by Ph.D. Roy Spencer, August 29, 2017 in GlobalWarming


As the Houston flood disaster is unfolding, there is considerable debate about whether Hurricane Harvey was influenced by “global warming”. While such an issue matters little to the people of Houston, it does matter for our future infrastructure planning and energy policy.

Let’s review the two basic reasons why the Houston area is experiencing what now looks like a new record amount of total rainfall, at least for a 2-3 day period over an area of tens of thousands of square miles.