earth science, amazon

Over the course of the Earth’s history, the planet has witnessed five mass extinctions. One of these was the result of a giant asteroid hitting the Yucatán Peninsula. This event triggered an extinction at the end of the Cretaceous period, killing off the dinosaurs. Far more common, however, are extinction events triggered by extensive volcanic activity.   

But how does rampant volcanism actually cause a mass extinction? The link between volcanic activity and climate is not so straightforward. Finding this connection was the goal of an international team of scientists led by Kunio Kaiho from Japan’s Tohoku University. The researchers studied the volcanic event that led to a mass extinction at the end of the Triassic Period. They recently published their findings in the journal Earth and Planetary Science Letters.

Volcanoes made way for the dinosaurs

About 200 million years ago, the end-Triassic extinction killed off about three-fourths of the world’s marine and land life. This was the end of trilobites, ammonoids, and gigantic crocodile-like animals called phytosaurs — fearful predators that could reach lengths of 12 meters. After phytosaurs disappeared, a niche was left open for dinosaurs, who survived the extinction and rose to dominance. 

Subscribe for counterintuitive, surprising, and impactful stories delivered to your inbox every Thursday

The end-Triassic extinction is normally thought to be connected to a huge eruption of the Central Atlantic Magmatic Province. This broad volcanic region developed the rift that split Pangea down the middle, separating the present-day Amazon from Western Africa, and North America’s Atlantic seaboard from Europe. 

The volcanic eruptions we see today are trivial in comparison. “Supercontinent rift-related volcanism [can] trigger this level of volcanic activity,” Kaiho told Big Think. As the supercontinent broke apart, four large surges of volcanism released huge amounts of gasses and lava. 

Yet how exactly volcanism relates to the extinction has remained unclear.  

How volcanism changes the atmosphere

To understand how widespread volcanic activity changes the climate, Kaiho’s team took samples of limestone and mudstone from strata corresponding to the end-Triassic period in present-day England and Austria. In the lab, they heated the stone to temperatures ranging from 350 to 1100 degrees Celsius, attempting to understand what happens when hot magma comes into contact with sedimentary rocks containing hydrocarbons and sulfur.

What they saw was surprising.

“Low-temperature heating formed [sulfur dioxide] from sulfide,” Kaiho explained. In the atmosphere, sulfur dioxide creates acid rain. It also blocks radiation from the sun, leading to global cooling in the short term (for about a decade). 

When they heated rock to higher temperatures, the team saw something else.  At these temperatures, carbon dioxide formed from hydrocarbons in the rocks. Carbon dioxide affects the environment for a much longer period of time, and unlike sulfur dioxide, it heats the Earth.

How does this relate to what actually happened?

Traces set in stone

Four major surges of volcanism marked the first 300,000 years of the end-of-Triassic extinction. The temperature of magma can be tracked, in a way, using a polycyclic aromatic hydrocarbon, or PAH, called coronene. This PAH needs high temperatures to form, so its presence can serve as a way to trace magma temperatures.

Looking at their samples, the team was able to measure coronene abundance and how it changed during the surges of volcanic activity. 

The first volcanic event corresponded to a low coronene index within the rock. This is consistent with low-temperature heating of magma over the course of about 100 to 300 years. These eruptions caused forest fires, soil erosion, and the first surge of marine extinction. Because of the low-temperature magma heating, sulfur dioxide was released, cooling the atmosphere. Overall, the globe could have cooled by 8° C, devastating life both on land and in the sea. 

After the second volcanic event, the world’s animals and plants began to recover. However, shortly later, the third and fourth volcanic surge occurred. The last three events all correspond to higher coronene indexes, indicating that the magma was much hotter. It released carbon dioxide and led to global warming.

These results show that the effect of volcanism on the environment is not always straightforward. It can lead to planetary-scale heating, but also to cooling.  


Companies have a simple and legal way to help their workers living in anti-abortion states—expanding paid time off

Credit: Unsplash/CC0 Public Domain Employers looking for ways to support their workers seeking abortions in states where it’s now illegal or soon will be don’t have it easy. From an employer’s standpoint, abortion is considered a type of health care benefit—and the rules that apply to that benefit are ...

View more: Companies have a simple and legal way to help their workers living in anti-abortion states—expanding paid time off

Scientists decipher, catalog the diverse origins of Earth's minerals

Nature has used 21 different ways over the last 4.5 billion years to create pyrite (aka Fool’s Gold) — the mineral world’s champion of diverse origins. Pyrite forms at high temperature and low, with and without water, with the help of microbes and in harsh environments where life plays ...

View more: Scientists decipher, catalog the diverse origins of Earth's minerals

Surprise 'fossil galaxy' spotted near mighty Andromeda

The smudge in the sky is a hint of what early galaxies looked like.

View more: Surprise 'fossil galaxy' spotted near mighty Andromeda

Life Helps Make Almost Half of Earth’s Minerals

A new origins-based system for classifying minerals reveals the huge geochemical imprint that life has left on Earth. It could help us identify other worlds with life too.

View more: Life Helps Make Almost Half of Earth’s Minerals

Diverse Origins of Earth’s Minerals: Helping Find New Minerals, Habitable Planets, and Extraterrestrial Life

A newly completed 15-year study details the origins and diversity of every known mineral on Earth. An innovative new perspective on mineralogy, findings rank amongst the field’s most important in the last century. Scientists decipher and catalog the diverse origins of Earth’s minerals; will inform models of life’s history, ...

View more: Diverse Origins of Earth’s Minerals: Helping Find New Minerals, Habitable Planets, and Extraterrestrial Life

How to find marker genes in cell clusters

Graphical abstract. Credit: Journal of Molecular Biology (2022). DOI: 10.1016/j.jmb.2022.167525 Which genes are specific for a certain cell type, i.e., “mark” their identity? With the increasing size of datasets nowadays, answering this question is often challenging. Often, marker genes are simply genes that have been found in specific cell ...

View more: How to find marker genes in cell clusters

Best early Amazon Prime Day PS5 deals 2022

Amazon Prime Day doesn’t officially start until 12th July, but you can already land some fantastic early deals, including discounts on popular PS5 games and PS5 accessories. Although we haven’t seen savings on the PS5 console itself, we have spotted some early offers on games, DualSense controllers (Amazon UK), ...

View more: Best early Amazon Prime Day PS5 deals 2022

Here are the most effective things you can do to fight climate change

The first three charts show, in descending order, how effective different behaviours are at cutting emissions. Credit: Max Callaghan, Author provided Limiting global warming to 1.5℃ above pre-industrial levels requires reaching net zero emissions by the middle of this century. This means that, in less than three decades, we ...

View more: Here are the most effective things you can do to fight climate change

How reindeer eyes transform in winter to give them twilight vision

Decrease in CO2 emissions during pandemic shutdown shows it is possible to reach Paris Agreement goals

Characterizing the materials for next-generation quantum computers with nonlinear optical spectroscopy

Chrysler Pacifica Hybrid vs. Toyota Sienna: Hybrid Minivan Showdown!

Waiting for the sun to set to find a rare bird

Research reveals the complexity of loneliness during lockdown

How old of a MacBook is still good for a student?

Saint Seiya: Legend of Justice celebrates achieving 1.5 million registrations with a series of giveaway events

Scientists unravel working principles of a promising material for fast-charging batteries

The Terminal List: Limited Series Review

123mkv Movie Download: Is it safe & legal to download movies from 123mkv?

Lung cancer: When radiation does not work


Top Car News Car News