October 2021 – Geobites

October 28, 2021October 28, 2021

Ancient Explosive Volcanoes on Mars

Featured image: a mushroom shaped volcanic plume arising from the explosive activity of Redoubt volcano, Alaska in 1990. Credit: R. Clucas.

Paper: Caldera Collapse and Volcanic Resurfacing in Arabia Terra Provide Hints of Vast Under-Recognized Early Martian Volcanism

Authors: Yin Yau Yoyo Chu, Joseph R. Michalski, Shawn P. Wright, A. Alexander G. Webb.

Mars is a planet of extreme highs and lows containing the solar system’s largest volcano – Olympus Mons – and the largest canyon system – Valles Marineris. Tharsis and Elysium, the planet’s two largest volcanic provinces, are young surface features that were built by basaltic volcanism throughout the Amazonian, the most recent geological era on Mars.

October 19, 2021October 18, 2021

What can a delta’s history tell us about groundwater’s future?

Feature image: Mosiac of the the Ganges Delta in false color created with imagery from the Sentinal 2 satilite. CC-By Annamaria Luongo, via Wikimedia Commons

Article: Linking the Surface and Subsurface in River Deltas—Part 2: Relating Subsurface Geometry to Groundwater Flow Behavior
Authors: Xu, Z., Hariharan, J., Passalacqua, P., Steel, E., Paola, C., & Michael, H. A.

Deltas are striking features on Earth’s surface, where rivers meet large water bodies. Their flow spreads out into many channels, depositing the sediment they have been carrying, potentially since their headwaters. This sediment creates and sustains the delta, which can be hundreds of miles across. Beyond being mesmerizing, deltas are essential to human civilization, past and present. Nearly half a billion people live on deltas around the world, where the deposited sediment hosts some of the most fertile agricultural land available.

October 13, 2021October 26, 2021

ExxonMobil and Climate Change Communications: A Case Study in Propaganda

Feature image from Pixabay

Article: Rhetoric and Frame Analysis of ExxonMobil’s Climate Change Communications

Authors: Geoffrey Supran & Naomi Oreskes

It’s no secret that ExxonMobil is a major architect of the climate crisis. The oil giants have allocated incredible amounts of time and resources to undermining climate science while continuing to pollute the planet. Now, a recent One Earth publication by Geoffrey Supran and Naomi Oreskes unpacks the way Exxon has so successfully spread propaganda while borrowing techniques from another destructive industry: that of tobacco. Exxon and other oil companies (often supported by powerful right-wing think tanks) have embarked on a propaganda campaign that has morphed from outright denial into a campaign aimed at distracting us, dividing political opinion, and convincing us that climate action is hopeless. Supran and Oreskes delve into the evolution of Exxon’s harmful contribution to this narrative.

October 12, 2021October 12, 2021

Ancient trees tell the story of modern climate change

Featured Image: Larch trees. Image courtesy North Cascades National Park, used with permission.

Paper: Spring arctic oscillation as a trigger of summer drought in Siberian subarctic over the past 1494 years

Authors: Olga V. Churakova Sidorova, Rolf T. W. Siegwolf, Marina V. Fonti, Eugene A. Vaganov, Matthias Saurer

Seemingly straight out of a fairytale, ancient trees are able to convey details about Earth’s complex history to the scientists willing and able to listen. Deep in the Siberian Arctic lie the secrets of past weather events, ocean currents, and droughts that occurred thousands of years ago, locked away in petrified wood and in the oldest living larch trees. We often hear in the news how the Siberian forest is victim to extreme drought and fire—something that is new as of the recent century. But how “new” are these events, and what exactly is perpetuating this new cycle?

October 8, 2021October 8, 2021

Call of Cthulhu — Can we uncover the secret of Pluto’s red spots?

Featuring image: Pluto is an icy object in the outer solar system. Its surface it not only covered by ice, but also by an unidentified red material. The largest of these red areas is the Cthulhu region in the southern hemisphere. NASA/JHUAPL/SwRI, public domain (CC0)

Paper: Testing tholins as analogues of the dark reddish material covering Pluto’s Cthulhu region

Authors: M. Fayolle, E. Quirico, B. Schmitt, L. Jovanovic, T. Gautier, N. Carrasco, W. Grundy, V. Vuitton, O. Poch, S. Protopapa, L. Young, D. Cruikshank, C. Dalle Ore, T. Bertrand, A. Stern

Pluto is an icy object beyond Neptune. Its surface is not only covered by innocent pale ice, but also by mysterious dark-red fields. What lurks in these hellish regions and where do they come from?

Far behind Neptune’s orbit, the icy body Pluto orbits our Sun. Pluto got a lot of attention in 2006, when it lost its status as a planet. Since then, it remained as a trans neptunian objects (TNO) of major interest. In 2015, Pluto presented itself in high resolution pictures for the first time in history, when NASA’s space probe New Horizons explored the outer regions of our solar system. What the pictures showed, was not the expected icy desert, but multiple areas of deep red all over Pluto’s surface. The largest of them is located on the southern hemisphere. As a homage to the master of subtle horror, H. P. Lovecraft, the area is called Cthulhu region, because some of the most mysterious and powerful beings in Lovecraft’s world originate from Pluto (in Lovecraft’s stories called Yuggoth). Fayolle and co-workers tried to better understand the origin of these red materials by using laboratory experiments and numerical modelling in comparison with the data recorded by the New Horizons space probe.