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.

On Sunday, Goulburn got colder than the BOM thought was possible (and a raw data record was “adjusted”)

by JoNova, July 2017

The BOM got caught this week auto-adjusting cold extremes to be less cold. Lance Pidgeon of the unofficial BOM audit team noticed that the thermometer at Goulburn airport recorded – 10.4°C at 6.17am on Sunday morning, but the official BOM climate records said it was -10.0°C. (What’s the point of that decimal place?) Either way this was a new record for Goulburn in July. (The previous  coldest ever July morning was -9.1°C. The oldest day in Goulburn was in August 1994 when it reached -10.9°C).

Coal Boom: 1600 new plants in 62 countries around the world – increasing 43%

by JoNova, July 2017

“End-Coal” Global Coal Tracker  does a magnificent job of showing how essential coal is around the world, and which countries are pathetically backwards in developing new coal plants. It’s probably not what the “CoalSwarm” team was hoping to achieve, but this map is a real asset to those of us who want to show how tiny Australia’s coal fired assets are compared to the rest of the world

Fungi are key players of the deep biosphere

by Linnaeus University, July 4, 2017

In addition to the life on the surface of the Earth and in its oceans, ecosystems have evolved deep under us in a realm coined the “deep biosphere” which stretches several kilometers down into the bedrock. Down there, the conditions are harsh and life is forced to adjust to a lifestyle that we at the surface would call extreme. One major difference to surface conditions is the lack of oxygen; a compound we take for granted and consider to be a prerequisite for survival but which subsurface life has to cope without.

Original article here (Nature Communication)

Geologic forces fueling West Antarctica’s Larsen Ice Shelf Cracks

by James Kamis, July 4, 2017 in ClimateChangeDispatch

Geological heat flow is fueling bottom melting and associated cracks across West Antarctica’s Larsen Ice Shelf, having little to do with man-made global warming. Significant amounts of high-quality data and relevant geological observations support this revelation, given historical and current geological mapping efforts done in Antarctica.

                                       see here, image credit NASA

See also here (in French)

Skillful prediction of northern climate provided by the ocean

by M. Arthur et al., June 20, 2017, in Nature Communication

We show that variations in ocean temperature in the high latitude North Atlantic and Nordic Seas are reflected in the climate of northwestern Europe and in winter Arctic sea ice extent. Statistical regression models show that a significant part of northern climate variability thus can be skillfully predicted up to a decade in advance based on the state of the ocean. Particularly, we predict that Norwegian air temperature will decrease over the coming years, although staying above the long-term (1981–2010) average. Winter Arctic sea ice extent will remain low but with a general increase towards 2020.

Pronounced differences between observed and CMIP5-simulated multidecadal climate variability in the twentieth century

by Sergey Kravtsov, June 15, 2017

The observed internal variability so estimated exhibits a pronounced multidecadal mode with a distinctive spatiotemporal signature, which is altogether absent in model simulations. This single mode explains a major fraction of model-data differences over the entire climate index network considered; it may reflect either biases in the models’ forced response or models’ lack of requisite internal dynamics, or a combination of both.

‘Perfect storm’ led to 2016 Great Barrier Reef bleaching

by James Cook University and Université Catholique de Louvain, July 3, 2017, in ScienceDaily

Professor Wolanski said the study was subjective to the extent that there was a lack of oceanographic field data in the Great Barrier Reef itself for the 2016 el Nino event. By contrast, the amount of oceanographic field data in the Torres Strait and the northern Coral Sea was very good.

“What we presented is our best-informed attempt to reveal the mechanisms involved in causing the event, based on the available oceanographic data combined with the existing body of knowledge on the water circulation in and around the Torres Strait/Northern Great Barrier Reef region.”

…Importance of CO2…

by Donn Dears, July 2017

Here is a summary of the graph’s salient points:

  • The CO2 safe limit for US Navy submarines is 8,000 ppm (Dotted red line)
  • The CO2 safe limit for the space station is 5,000 ppm (Dotted blue line)
  • A line depicting the gradual doubling of CO2 is near the bottom of the graph
  • The minimum atmospheric CO2 requirements to sustain plant growth is 150 ppm (Dotted green line)

In addition, atmospheric CO2 has been as high as 7,000 ppm approximately 550 million years ago, and as high as 2,000 ppm as recently as 150 million years ago. (Also here in French)

What the graph clearly shows is how close mankind came to extinction when atmospheric CO2 levels dropped to 183 ppm during the last ice age.

China Met Office Confirms Global Warming Hiatus

by Dr David Whitehouse, July 4, 2017 in GWPF

The China Meteorological Administration (CMA) has recently developed a new global monthly land-surface air temperature data set called CMA GLSAT. Using it researchers from the administration reanalysed the change in global annual mean land-surface air temperature during three time periods (1901–2014, 1979–2014 and 1998–2014) to see if there was any evidence of a hiatus or pause in recent surface global warming.

The researchers find very clear evidence for the recent warming hiatus. Their results show linear trends of 0.104 °C per decade, 0.247 °C per decade and 0.098 °C per decade for the three periods, respectively. The trends were statistically significant except for the period 1998–2014, the period that is also known as the ‘‘warming hiatus”.