Science: tiny crystals can make volcanoes explode, eruptions and natural temperature variability, Australian Maliwawa rock art scenes, a supernova explosion in the Earth’s proximity

Tavurvur volcano, New guinea on June 07, 2009. Photo: Taro Taylor / <a href="https://commons.wikimedia.org/"target="_blank">Wikimedia Commons</a>, <a href=" https://en.wikipedia.org/wiki/Creative_Commons_license"target="_blank">Creative Commons License</a>

Recent discoveries about our planet, its rocks and other “stone” topics

Tiny crystals, ten thousand times thinner than a human hair, can cause explosive volcanic eruptions: They increase the viscosity of the underground magma, and as a result, the build-up of rising gases may finally be set free in a massive eruption.
http://www.bristol.ac.uk/news/2020/september/nanolites.html
 

Driftwood in Siberia. Photo: University of CambridgeTestimony of trees: Over the past 2,000 years, volcanoes have played a larger role in natural temperature variability than previously thought, and their climatic effects may have contributed to past societal and economic change. Researchers used samples from more than 9000 living and dead trees to obtain a precise yearly record of summer temperatures in North America and Eurasia, dating back to the year 1 CE. The revealed colder and warmer periods coincide with records of very large volcanic eruptions as well as major historical events.
https://www.cam.ac.uk/research/news/the-testimony-of-trees-how-volcanic-eruptions-shaped-2000-years-of-world-history
 

Maliwawa human figures from an Awunbarna siteAustralian Maliwawa rock art scenes were not just simple depictions of everyday life, but also communicate aspects of the artists‘ cultural beliefs, with an emphasis on important animals and interactions between humans and other humans or animals. Newly discovered examples of this Australian rock art from 6000 to 9400 B.C. painted in various shades of red “open a window to the past“, researches say.
https://newsroom.taylorandfrancisgroup.com/arnhem-land-maliwawa-rock-art-opens-window-to-past/
 

This manganese crust started to grow about 20 million years ago. In layers that are around 2.5 million years old, the researchers found iron-60 and elevated levels of manganese-53 giving evidence of a near-Earth supernova 2.5 million years ago. Photo: Dominik Koll / TUMWhen the brightness of the star Betelgeuse dropped dramatically a few months ago, some observers suspected an impending supernova – a stellar explosion far away that could cause damage on Earth. While Betelgeuse has returned to normal, physicists from the Technical University of Munich (TUM) have found evidence of such an event 2,5 million years ago (1, 2, 3).

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(10.10.2020)