Archives par mot-clé : Geology

Flourishing ocean drives the end-Permian marine mass extinction

by Martin Schobben et al., July 2014,


The Permian geologic period that ended the Paleozoic era climaxed around 252 million years ago with a sweeping global mass extinction event in which 90 to 95 percent of marine life became extinct. It would take 30 million years for planetary biodiversity to recover. Understanding the contributing factors of the end-Permian mass extinction is critical to understanding and perhaps mitigating the current anthropogenic climate change.

Engineers have dispelled a 100-year-old scientific law used to describe how fluid flows through rocks

by Imperial College London, July 17, 2017, in ScienceDaily


The discovery by researchers from Imperial could lead to a range of improvements including advances in Carbon Capture and Storage (CCS). This is where industrial emissions will be captured by CCS technology, before reaching the atmosphere, and safely stored in rock deep underground.

See also here

Ancient plankton-like microfossils span two continents

by Penn State, July 13, 2017 in ScienceDaily


Large, robust, lens-shaped microfossils from the approximately 3.4 billion-year-old Kromberg Formation of the Kaapvaal Craton in eastern South Africa are not only among the oldest elaborate microorganisms known, but are also related to other intricate microfossils of the same age found in the Pilbara Craton of Australia, according to an international team of scientists.

…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.

Life on Earth was nearly doomed by too little CO2

by  Dennis T. Avery, June 30, 2017 in WUWT


Carbon dioxide truly is “the gas of life.” The plants that feed us and wildlife can’t live without inhaling CO2, and then they exhale the oxygen that lets humans and animals keep breathing.

Our crop plants evolved about 400 million years ago, when CO2 in the atmosphere was about 5000 parts per million! Our evergreen trees and shrubs evolved about 360 million years ago, with CO2 levels at about 4,000 ppm. When our deciduous trees evolved about 160 million years ago, the CO2 level was about 2,200 ppm – still five times the current level.

See also here (in French)

‘Bulges’ in volcanoes could be used to predict eruptions

by University of Cambridge, June 28, 2017 in ScienceDaily


Using a technique called ‘seismic noise interferometry’ combined with geophysical measurements, the researchers measured the energy moving through a volcano. They found that there is a good correlation between the speed at which the energy travelled and the amount of bulging and shrinking observed in the rock. The technique could be used to predict more accurately when a volcano will erupt. Their results are reported in the journal Science Advances.

A map that fills a 500-million year gap in Earth’s history

by Prof.  A. Collins and PhD A. Merdith, June 27, 2017


Earth is estimated to be around 4.5 billion years old, with life first appearing around 3 billion years ago.

To unravel this incredible history, scientists use a range of different techniques to determine when and where continents moved, how life evolved, how climate changed over time, when our oceans rose and fell, and how land was shaped. Tectonic plates – the huge, constantly moving slabs of rock that make up the outermost layer of the Earth, the crust – are central to all these studies.

Along with our colleagues, we have published the first whole-Earth plate tectonic map of half a billion years of Earth history, from 1,000 million years ago to 520 million years ago.

See also here  and here (in French)

Norway offers oil firms record number of Arctic blocks

by AFP/UKnews, June 21, 2017


Norway on Wednesday proposed to open up a record number of blocks in the Barents Sea to oil exploration despite protests from environmentalists and others fearing possible damage to the Arctic region.

The Norwegian oil and energy ministry offered oil companies 93 blocks in the Barents Sea and nine others in the Norwegian Sea, all located beyond the Arctic Circle.