Getting to Grips With the Sixth Mass Extinction

Featured Image: It is well-understood that the Earth’s biodiversity is in severe decline. However, it is less clear if this decline can now be called a mass extinction. Public domain image via. The Wilderness Society.

Paper: The Sixth Mass Extinction: fact, fiction, or speculation?

Authors: Robert H Cowie, Philippe Bouchet & Benoît Fontaine

Human-driven emissions and land use changes have impacted Earth’s biosphere greatly, causing global extinction rates to climb fast. However, does the current undeniable biodiversity crisis meet the requirements to be called a mass extinction? 

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Chicxulub’s small sibling

Featuring image: 66 million years ago, a giant meteorite impact ended the age of the dinosaurs. Artist impression of the impact. Painting by Donald E. Davis, Public Domain (C0)

Paper: The Nadir Crater offshore West Africa: A candidate Cretaceous-Paleogene impact structure

Authors: U. Nicholson, V. J. Bray, S. P. S. Gulick, B. Aduomahor

The appearance of a flaming, 10 km wide meteorite over the Gulf of Mexico must have been striking, literally. But could the meteorite, which killed the dinosaurs, have had a small sibling or even a whole family of smaller space rocks hurtling towards Earth?

The massive meteorite impact at Chicxulub in the Gulf of Mexico ended the era of the dinosaurs 66 million years ago. Now, only a few thousand km apart from it, researchers might have found another, smaller crater of a similar age. And it might show that the Chicxulub meteorite was not alone but part of a cluster of meteorites, bombarding the Earth at the end of the Cretaceous period.

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The rise of Sponges

Featuring image: Venus flower basket glass sponges (Euplectella aspergillum) in the Gulf of Mexico. NOAA Okeanos Explorer Program – Gulf of Mexico 2012 Expedition, CC-BY-2.0

Paper: Palaeoecological Implications of Lower-Middle Triassic Stromatolites and Microbe-Metazoan Build-Ups in the Germanic Basin: Insights into the Aftermath of the Permian–Triassic Crisis

Authors: Y. Pei, H. Hagdorn, T. Voigt, J.-P. Duda, J. Reitner

The Permian-Triassic crisis was the greatest mass extinction in Earth’s history. But an unlikely animal might have benefited from this cataclysm: the sponge.

Microbial mats like stromatolites represent the lithified remains of different slimy accumulations of microorganisms. While there are many different types, Pei and co-workers investigated a special type of microbial mats with a very different internal structure, called microbial-metazoan build-up, mainly consisting of sponges. By comparing these fossil structures to common stromatolites from the Permian-Triassic boundary, the researcher team could show that sponges profited from the mass extinction with the aid of bacteria.

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One Sailors’ Legend Down, Many More To Go – Multiple Milky Sea Events Detected by Satellite

Processed satellite images showing a milky sea event in Java, 2019.

Featured image: Processed satellite images showing a milky sea event and its components in Java, 2019. From Miller et al, 2021 (figure 5).

Paper: Miller, S.D., Haddock, S.H.D., Straka, W.C. et al. Honing in on bioluminescent milky seas from space. Sci Rep 11, 15443 (2021). https://doi.org/10.1038/s41598-021-94823-z

Sailors see a lot of, well, stuff while they’re far from land. And they’re known for telling unbelievable tales, some of which later turn out to be more or less true. Milky seas are one of those: a horizon-to-horizon sea that glows white like the snow in the moonlight. In a 2021 paper, Dr. Steven Miller of Colorado State University and colleagues used satellites to look for these systems in hopes of understanding how and why these glowing patches form.

The first satellite detection of a milky sea event was also the work of Dr. Miller, in a 2005 paper that detected just a single event by combing ships’ logs and satellite archives from the preceding decade. Now, Miller’s research team has refined the algorithm that he’d previously developed for modern satellite records. Today’s satellite technology is better able to ‘see’ these events due to higher resolution of their images and can pick out the bioluminescent glow of microbes in the ocean better than the last generation of satellites.

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Understanding highly explosive basaltic eruptions using simulations

Featured image: A fissure cone of Kīlauea (Hawaii) erupting during the 2018 eruptive episode. via Wikimedia commons (Public domain)

Paper: Role of volatiles in highly explosive basaltic eruptions.

Authors: Giuseppe La Spina, Fabio Arzilli, Mike R. Burton, Margherita Polacci, Amanda B. Clarke

When we think of Hawaii or Iceland, the first thing that comes to mind is volcanoes. Lava fountains spew out basaltic lava, which silently meanders its way to the ocean. The notion that basaltic eruptions are always less explosive compared to other types like rhyolitic and andesitic eruptions is not entirely true. For example, Mount Etna in Italy has produced highly explosive basaltic eruptions such as the 122 BCE Plinian Eruption and another in 1669. Because highly explosive basaltic eruptions are not very common, they’re not fully understood leaving scientists wondering “What could be the reason behind this erratic behaviour?”

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What Makes a Supervolcano “Super”?

Featured Image: Yellowstone National Park attracts millions of people a year and has been a major focal point for discussions about supervolcanoes in recent decades. Public domain image via pixabay.

Paper: Capturing the Extreme in Volcanology: The Case for the Term “Supervolcano”

Authors: S. De Silva & S. Self

The earth sciences can be challenging to communicate. Definitions change over time and, in some cases, become widely reported in the media and often without a formal definition. A recent paper by Shanaka de Silva and Stephen Self addresses these issues surrounding the popular word “supervolcano.” The authors discuss the variables used to distinguish between these extreme events and regular eruptions. They then suggest a new working definition for researchers to use moving forward, clearing up much confusion that surrounds the word. The concept of supereruptions exploded in popularity after the 2005 Discovery TV/BBC documentary Supervolcano, promoted with the by-line “Is Yellowstone Overdue?

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Is geothermal energy fit for megacities?

Featured image: Steam rising from Nesjavellir Geothermal Power Station in Iceland via Wikimedia commons. Public Domain.

Article: Geothermal energy as a means to decarbonize the energy mix of megacities

Authors: Carlos A. Vargas, Luca Caracciolo, Philip Ball

As the world grapples with climate change, the transition to renewable energy has become a necessity. Governments are investing heavily in solar and wind power to reduce the dependence on fossil fuels. Another non-conventional source of energy that’s still understudied is geothermal energy. But what is geothermal energy? Geo means earth, thermal means heat. The internal heat of Earth is harnessed to heat water and produce power. An advantage of using geothermal energy over solar and wind is that, it doesn’t rely on weather to produce electricity. It provides clean, constant, stable and predictable supply of power. The question is, can geothermal energy cater to the demand of megacities where a large chunk of the world’s population resides?

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Our enduring fascination with groundwater springs

Landscape with mountains in the distance and trees, rocks, and a path in the foreground

Featured Image: The middle zone of the Gerecse Mountains in Hungary via Wikimedia Commons. Public Domain.

Article: Springs regarded as hydraulic features and interpreted in the context of basin-scale groundwater flow
Authors:
Tóth, Á., Kovács, S., Kovács, J., & Mádl-Szőnyi, J.

O Fount Bandusia, brighter than crystal,
worthy of sweet wine and flowers,
tomorrow shalt thou be honoured with
a firstling of the flock whose brow,

with horns just budding, foretokens love
and strife. Alas! in vain; for this
offspring of the sportive flock shall
dye thy cool waters with its own red blood.

Thee the fierce season of the blazing
dog-star cannot touch; to bullocks wearied
of the ploughshare and to the roaming flock
thou dost offer gracious coolness.

Thou, too, shalt be numbered among the
far-famed fountains, through the song I
sing of the oak planted o’er the grotto
whence thy babbling waters leap.

Horace (56BC-8BC) Ode 3.13

This ode by the Roman poet Horace is part of a long tradition of art and literature honoring groundwater springs, called ‘founts’ or ‘fountains’ in this translation. It is no wonder why: they can provide high-quality water that continues to flow even in the heat of a Mediterranean summer, “the fierce season of the blazing dog-star,” when surface water is often not available. But where does this water come from? Is it from large underground lakes, as the Romans suspected? Some of the same characteristics Horace names in this poem can help scientists figure this out.

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Ice from fire – When volcanos let it snow

Featuring image: Erruption of the Raikoke Volcano on June 22, 2019. Volcanos can exhaust a large amount of gases and dust during eruptions. Is this enough to create an atmosphere on the Moon? NASA’s Earth Observatory, public domain (CC0).

Paper: Polar Ice Accumulation from Volcanically Induced Transient Atmospheres on the Moon

Authors: A. X. Wilcoski, P. O. Hayne and M. E. Landis

The Moon is a silent and dry, yet beautiful desert. Where it comes from and how much ice exits is still a mystery. It can be found in the darkness of its pole regions as ice. Surprisingly, the eruptions of volcanos might have helped the Moon to keep its water.

The gas that is set free during a volcano eruption contains different volatile molecules, including water. On small celestial objects without an atmosphere like the moon, most of the gases are released to space. A new study suggests that not all water vapour from such eruptions escaped from the Moon during its history. Instead, local and short-lived atmospheres might have formed during eruptions, allowing a part of the water vapour to cool down and deposit as snow and ice.

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How Machine Learning Helps in the Fight Against Climate Change

Featured Image: Machine Learning has proven itself to be an effective tool in interdisciplinary research, but how can it be useful in understanding climate change? CC BY-NC 4.0, via. Dean Long

Paper: Tackling Climate Change with Machine Learning (Chapter 8)

Authors: David Rolnick et al.

Machine Learning (ML) gives researchers extremely valuable ways of revealing patterns within enormous datasets, and making predictions. Climate change research is one of many fields that is beginning to explore ML approaches. There are three major areas of interest: (1) climate prediction/modeling, (2) assessing impacts, and (3) exploring solutions as we attempt to decarbonize energy production. Rolnick and his coworkers explored the merit of machine learning in climate research and where it can support scientists best. The authors also call for greater collaboration between researchers of different backgrounds to advance our understanding of such a complex issue.

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