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.

Puerto Rico’s Hurricane History

by P.  Homewood, September 22, 2017 in NotaLotofPeopleKnowThat


As Hurricane Maria heads north as a Cat 3 storm, much is being made of the fact that it is the strongest hurricane to hit Puerto Rico since 1928. The implication is that Maria must have been exceptionally strong.

But the reality is that Puerto Rico is little more than a speck in the vastness of the Atlantic Ocean. The odds of the eye of a major hurricane, often just 10 or 20 miles wide, making a direct hit on Puerto Rico are probably hundreds to one, given that there are thousands of miles of ocean through which hurricanes can commonly travel.

See also here

Study: plants are globally getting more efficient thanks to rising carbon dioxide

by University of California, September 12, 2017 in WUWT


A trend toward greater discrimination under higher CO2 levels is broadly consistent with tree ring studies over the past century, with field and chamber experiments, and with geological records of C3 plants at times of altered atmospheric CO2, but increasing discrimination has not previously been included in studies of long-term atmospheric 13C/12C measurements. We further show that the inferred discrimination increase of 0.014 ± 0.007‰ ppm−1 is largely explained by photorespiratory and mesophyll effects.

Diamonds show Earth still capable of ‘superhot’ surprises

by Europlanet Media Centre, September 21, 2017 in ScienceDaily


Diamonds may be ‘forever’ but some may have formed more recently than geologists thought. A study of 26 diamonds, formed under extreme melting conditions in the Earth’s mantle, found two populations, one of which has geologically ‘young’ ages. The results show that certain volcanic events on Earth may still be able to create super-heated conditions previously thought to have only existed early in the planet’s history before it cooled. The findings may have implications for diamond prospecting.

See also here

In times of climate change: What a lake’s color can tell about its condition

by Forschungsverbund Berlin e.V. (FVB), September 21, in ScienceDaily


With the help of satellite observations from 188 lakes worldwide, scientists have shown that the warming of large lakes amplifies their color. Lakes which are green due to their high phytoplankton content tend to become greener in warm years as phytoplankton content increases. Clear, blue lakes with little phytoplankton, on the other hand, tend to become even bluer in warm years caused by declines in phytoplankton. Thus, contrary to previous assumptions, the warming of lakes tends to amplify their richness or poverty of phytoplankton.

See also here

Are the glaciers in Glacier National Park growing? Lysander Spooner University investigates climate claims

by Lysander Spooner University, September 2017


(…) Upon our return to the Hotel after visiting the Glacier, we noticed that our brand-new photos appear to show that the Grinnell Glacier has grown slightly from the 2008 images that are displayed on the Hotel walls. There has been no reporting of this in any newspaper or broadcast that we know of. (In fact, all news coverage reports the precise opposite.) The smaller Gem Glacier—which is visible from the valley miles below—also appears to be slightly larger than it is shown in 2008 pictures on display.

See also here

Trends In Atlantic Hurricanes

by Paul Homewood, September 20, 2017 in NotaLotof PeopleKnowThat


It is worth re-emphasising these points:

  • Many storms were missed over the open ocean prior to hurricane hunter aircraft in 1944.

  • Even then half of the Atlantic basin was not covered.

  • Satellite coverage began to improve matters in 1966.

  • But even then monitoring has considerably improved since 1966, particularly regarding short lived storms.

    See also herehere and here

Is the world warming to clean coal?

by Sebastien Laye, September 18, 2017 in NotaLotofPeopleKnowThat


Those voices are the impetus behind what Subramanian calls a “green and clean coal coalition” spanning both the developed and developing worlds. Emerging markets in Asia and Africa will continue to build new coal-fired power stations for at least the next two decades. In that timeframe, coal-fired solutions are indispensable to meeting their demands for electrification and growth. As clean coal solutions emerge, new plants in the developing world can and should be far cleaner than previous generations of coal-fired plants in Europe and America.

CLIMATE CHANGE WILL TAKE LONGER, SAY SCIENTISTS

by Dr David Whitehouse, September 19, 2017 in GWPF


The study is published in the journal Nature Geoscience by a team of scientists led by Richard Millar of the University of Oxford. It has recalculated the carbon budget for limiting the Earth’s warming to 1.5 degrees Celsius above temperatures seen in the late 19th century. It had been widely assumed that this stringent target would prove unachievable, but the new study would appear to give us much more time to act if we want to stay below it.

See also here and  here

The Correlation of Seismic Activity and Recent Global Warming

by Arthur Viterio, 2016, in  J Earth Science Climate Change


Earth’s climate is a remarkably “noisy” system, driven by scores of oscillators, feedback mechanisms, and radiative forcings. Amidst all this noise, identifying a solitary input to the system (i.e., HGFA MAG4/6 seismic activity as a proxy for geothermal heat flux) that explains 62% of the variation in the earth’s surface temperature is a significant finding.

See also here

Irma : un record de rumeurs

by Cédric Moro, 18 septembre 2017 in Mythes,Mancies&Mathématiques


Que n’a-t-on pas entendu dans une partie de la presse et dans les déclarations à chaud de scientifiques et d’experts du climat sur l’uragan Irma. C’était du jamais vu, du jamais mesuré, d’une puissance inégalée, Europe 1 allant jusqu’à parler « du plus important de l’histoire climatologique ». Des eaux extraordinairement chaudes devaient expliquer son intensité effroyable (sous-entendu :  Irma, c’est la faute au réchauffement), ses vents destructeurs records, son diamètre exceptionnel, ses pluies diluviennes, son raz de marée démesuré, son intensification inouïe ou ses dégâts hors normes…

La revanche des pétroles de schiste

by Connaissance des Energies, 18 septembre 2017


Après avoir vu leur production tripler entre 2010 et 2014, les « light tight oil » américains (LTO), fréquemment appelés « pétroles de schiste », ont fait preuve d’une résilience étonnante lors de la chute des prix. Ils surprennent aujourd’hui à nouveau les marchés et pourraient contrarier la stratégie de l’OPEP.

Dans cette étude publiée par le Centre Énergie de l’Ifri, Sylvie Cornot-Gandolphe (voir le .pdf ci-dessous) présente les grands changements du secteur des LTO américains au cours des dernières années en expliquant leur résilience lors de la chute des cours et leurs perspectives de croissance.

 

Egalement ce .pdf fort complet

Nature Unbound V – The elusive 1500-year Holocene cycle

by Javier,  September 15, 2017, in Judith Curry Climate Etc.


The existence of a 1500-year climatic cycle during the Holocene, related to the glacial Dansgaard-Oeschger cycle, is a matter of intense debate. However, by introducing precise timing requirements it can be shown that the 1500-year cycle displayed in Northern Hemisphere glacial records is also observed in Holocene records from all over the world.

The cycle is most prominently displayed in oceanic subsurface water temperatures, Arctic atmospheric circulation, wind deposits, Arctic drift ice, and storminess records.