Archives par mot-clé : Africa

Are We Seeing a New Ocean Starting to Form in Africa?

by Klemetti, E., May 8, 2020 in EOS


Although shallow magma storage at Erta Ale volcano hints at a rift-to-ridge transition, the tectonic future of the Afar region is far from certain.

Standing next to a lava lake at the summit of a massive volcano, Christopher Moore, a Ph.D. candidate at the School of Earth and Environment at the University of Leeds in the United Kingdom, could see the red haze of lava flows a few kilometers away. This might seem like a rare sight, but at Ethiopia’s Erta Ale, it’s business as usual.

Are such behaviors the first signs of a tectonic transition? This question is part of what Moore has been studying at Erta Ale. The entire Afar region in eastern Africa finds itself in the middle of changes that could split the continent, forming a new ocean basin. The magmatism at Erta Ale might be offering signs of this switch by mimicking the characteristics of a mid-ocean ridge.

Satellite image of eastern Africa, with the Red Sea and the Gulf of Aden to the east
The East African Rift valley, the Red Sea, and the Gulf of Aden are clearly visible in this Landsat 8 image, taken on 8 November 2019. Credit: NASA/Erik Klemetti

However, there isn’t agreement about how close the Afar region is to this tectonic transition. The geophysical characteristics of magma storage at Erta Ale could point to the region’s conversion to an incipient oceanic spreading center, but the petrology of the erupting lava might be telling us that we aren’t there yet.

Again Reality Goes In Opposite Direction Of Climate Models…”Confidence In Models Correspondingly Low”

by P. Gosselin, March 27, 2019 in NoTricksZone


Real vegetation development in southern Africa takes a very different course than claimed by climate models

By Die kalte Sonne
(German translated by P Gosselin)

Climate models provide answers to all conceivable questions about the future. Political decision-makers are grateful for this information because they can make their plans accordingly.

But are the forecasts derived from models correct at all?

A research team led by Timm Hoffman has now compared the model projections with real vegetation development in southern Africa using historical photos. The sobering result: Nature has mostly developed quite differently than assumed by the models. In contrast to the model assumptions, no significant long-term trend in precipitation could be observed. Vegetation belts, which were supposed to shrink, ended up expanding. Confidence in the models is correspondingly low.

Political planning or even CO2 damage calculations based on the simulations are not possible. Here is the abstract of the work published in the journal Anthropocene in March 2019:

Southern Africa vegetation expanding, images show. Source: here.

Carbon emissions in African savannas triple previous estimates

by Edinburgh University, August 24, 2018 in ScienceDaily


The findings highlight the extent to which humans are impacting one of the world’s major ecosystems — the Miombo woodlands, which cover 2.5 million square kilometres, across countries including Angola, Zambia, Tanzania and Mozambique.

At the same time, however, the growing number of trees in remote parts of these woodlands is helping to offset the emissions, researchers say.

The study is the first to provide an in-depth analysis of areas gaining carbon while also losing it through degradation — a process where some, but not all, trees are removed, usually as a result of logging and fire.

See original article in Nature

Caught on video: small asteroid hits Earth with force of 500 Tons of TNT

by Anthony Watts, June 4, 2018 in WUWT


A small asteroid hit Earth on Saturday, June 2nd, exploding in the atmosphere over Botswana before it could reach the ground. The Catalina Sky Survey in Arizona had discovered the space rock only hours earlier as it hurtled toward our planet from inside the orbit of the Moon. Sensors used to monitor rogue nuclear explosions detected the asteroid and estimated its yield near ~500 tons of TNT.

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Lake Chad Might Be Shrinking, But It Has Nothing To Do With Climate Change

by P. Homewood, April 1, 2018 in NotaLotofPeopleKnowThat


Lake Chad – a source of water to millions of people in West Africa – has shrunk by nine-tenths due to climate change, population growth and irrigation. But can a scheme dating back to the 1980s save it?

“It’s a ridiculous plan and it will never happen.” That’s the reaction many people have to the idea of trying to fill up Lake Chad and restore it to its former ocean-like glory by diverting water from the Congo river system 2,400km (1,500 miles) away.

Why the seafloor starts moving Marine scientists find possible cause of landslides off Northwest Africa

by Helmholtz Centre for Ocean Research Kiel (GEOMAR), February 13, 2018 in ScienceDaily


When the seabed loses its stability and starts to move, it often happens in much larger dimensions than landslides ashore — and at slopes with very low gradients. At the same time, discplacement of large amounts of sediment under water scan cause devastating tsunamis. However, why and when submarine landslides develop is hardly understood. Marine scientists have now published possible causes based on observations on submarine landslides off the coast of northwest Africa.

Tropical explosive volcanic eruptions can trigger El Niño by cooling tropical Africa

by M. Khodri et al., October 3,  2017 in Nature


Stratospheric aerosols from large tropical explosive volcanic eruptions backscatter shortwave radiation and reduce the global mean surface temperature. Observations suggest that they also favour an El Niño within 2 years following the eruption. Modelling studies have, however, so far reached no consensus on either the sign or physical mechanism of El Niño response to volcanism