Earth Archives

January 8, 2021January 8, 2021 by Evan Gough

These Bizarre Cloud Patterns are von Kármán’s Vortices, Caused by the air Wrapping Around Tall Islands

Three peaks in Cape Verde form von Kármán vortex streets when wind conditions are right. Image Credit: Lauren Dauphin, using MODIS data from NASA EOSDIS/LANCE and GIBS/Worldview.

This is an image of some of the islands that make up the nation of Cape Verde. While most in that group of ten islands are flat, some are very tall: Fogo, Santa Antão, and São Nicolau. Those three stand well above their compatriots, with Fogo reaching an altitude of 2,829 metres (9,281 feet).

The three tall volcanic islands sometimes interact with the wind to create von Kármán vortices, also called von Kármán vortex streets.

December 7, 2020December 7, 2020 by Evan Gough

Iceberg A-68A is Turning. Will it Miss South Georgia Island After All?

The iceberg A-68A floating in open waters about 1050 km from its birthplace. It's been floating for three years. Image Credit: contains modified Copernicus Sentinel data (2020), processed by ESA, CC BY-SA 3.0 IGO

A massive iceberg named A-68A is on a long journey through the seas near Antarctica. Though largely empty, those waters do host some islands, most notably South Georgia Island. In recent weeks satellite images showed the iceberg heading right for South Georgia.

That upcoming collision could have devastating consequences for wildlife that congregates on the island. But now, it looks like the collision might not happen.

November 19, 2020November 19, 2020 by Evan Gough

There Might Be Water On All Rocky Planets

Artist’s impression of a massive asteroid belt in orbit around a star. Earth's water may not have all come from asteroids and comets, so maybe that's true for exoplanets. Credit: NASA-JPL / Caltech / T. Pyle (SSC)

If you asked someone who was reasonably scientifically literate how Earth got its water, they’d likely tell you it came from asteroids—or maybe comets and planetesimals, too—that crashed into our planet in its early days. There’s detail, nuance, and uncertainty around that idea, but it’s widely believed to be the most likely reason that Earth has so much water.

But a new explanation for Earth’s water is emerging. It says that the water comes along for the ride when Earth formed out of the solar nebula.

If that’s correct, it means that most rocky planets might have water for at least a portion of their lives.

November 18, 2020November 18, 2020 by Evan Gough

An Iceberg the Size of South Georgia Island is on a Collision Course with… South Georgia Island

Back in July 2017, satellites watched as an enormous iceberg broke free from Antarctica’s Larsen C ice shelf on the Antarctic Peninsula. The trillion-ton behemoth has been drifting for over three years now. While it stayed close to its parent ice shelf for the first couple of years, it’s now heading directly for a collision with South Georgia Island.

It could be a slow-motion collision, but a collision nonetheless. If it does collide with the island and its shallow sea-floor, it won’t be the first iceberg to do so. And if the first one was any indication, wildlife could suffer.

November 18, 2020November 18, 2020 by Evan Gough

There’s a Vast Microbial Ecosystem Underneath the Crater that Wiped Out the Dinosaurs

A three-dimensional cross-section of the hydrothermal system in the Chicxulub impact crater and its seafloor vents. The system has the potential for harboring microbial life. Illustration by Victor O. Leshyk for the Lunar and Planetary Institute.

How did life arise on Earth? How did it survive the Hadean eon, a time when repeated massive impacts excavated craters thousands of kilometres in diameter into the Earth’s surface? Those impacts turned the Earth into a hellish place, where the oceans turned to steam, and the atmosphere was filled with rock vapour. How could any living thing have survived?

Ironically, those same devastating impacts may have created a vast subterranean haven for Earth’s early life. Down amongst all those chambers and pathways, pumped full of mineral-rich water, primitive life found the shelter and the energy needed to keep life on Earth going. And the evidence comes from the most well-known extinction event on Earth: the Chicxulub impact event.

October 27, 2020October 27, 2020 by Evan Gough

Scientists in Japan Have Found a Detailed Record of the Earth’s Last Magnetic Reversal, 773,000 Years Ago

Earth Observation has come a long way. But if satellites could orbit closer to Earth, in VLEO, then our observations would be a lot better. Image Credit: NASA Earth Observatory.

Every 200,000 to 300,000 years Earth’s magnetic poles reverse. What was once the north pole becomes the south, and vice versa. It’s a time of invisible upheaval.

The last reversal was unusual because it was so long ago. For some reason, the poles have remained oriented the way they are now for about three-quarters of a million years. A new study has revealed some of the detail of that reversal.

October 23, 2020October 23, 2020 by Evan Gough

Geologists Have Found the Earth’s Missing Tectonic Plate

This image shows plate tectonic reconstruction of western North America 60 million years ago showing subduction of three key tectonic plates, Kula, Farallon and Resurrection. Image Credit: Wu and Fuston 2020.

Northern Canada has been keeping a secret from the rest of the world. It’s home to “Resurrection,” a tectonic plate that has been much theorized but never found until now. A team of researchers used what amounts to a CAT scan of northern Canada and the mantle underneath it to find the missing plate.

Finding it could lead to better hazard prediction and also to finding mineral and hydrocarbon deposits. But better than that, it’s helping scientists piece together Earth’s history.

October 22, 2020October 22, 2020 by Evan Gough

Scientists Think They Know What Caused the Deadliest Mass Extinction in the History of the Earth

This illustration shows the percentage of marine animals that went extinct during Earth's worst extinction at the end of the Permian era by latitude, from the model (black line) and from the fossil record (blue dots).A greater percentage of marine animals survived in the tropics than at the poles. The color of the water shows the temperature change, with red being most severe warming and yellow less warming. At the top is the supercontinent Pangaea, with massive volcanic eruptions emitting carbon dioxide. The images below the line represent some of the 96 percent of marine species that died during the event. [Includes fossil drawings by Ernst Haeckel/Wikimedia; Blue crab photo by Wendy Kaveney/Flickr; Atlantic cod photo by Hans-Petter Fjeld/Wikimedia; Chambered nautilus photo by John White/CalPhotos.]Justin Penn and Curtis Deutsch/University of Washington

Humanity can have a love/hate relationship with itself, but there’s no denying that we’re the pinnacle of evolution on Earth as things stand now. But it took an awfully long time for evolution to produce beings such as we. Several times, life had to drag itself back from near annihilation.

The largest extinction setback was the Permian-Triassic extinction, also called the “Great Dying,” some 252 million years ago. Up to 96% of all marine species and 70% of terrestrial vertebrate species went extinct.

What happened?

October 17, 2020October 17, 2020 by Nancy Atkinson

Great Barrier Reef Has Lost Half of its Coral Over the Last 25 Years

Great Barrier Reef, Queensland, Australia August 1992

A new study found that warmer ocean temperatures driven by climate change have caused Australia’s Great Barrier Reef to lose more than half of its corals since 1995. The researchers say virtually all coral populations along the Great Barrier Reef have declined due to repeated “bleaching events” in the past 25 years. They said the devastation of the coral will continue unless action is taken to mitigate the causes of a warming climate.

October 2, 2020October 2, 2020 by Evan Gough

A Supernova Exploded Dangerously Close to Earth 2.5 Million Years Ago

Visible, infrared, and X-ray light image of Kepler's supernova remnant (SN 1604) located about 13,000 light-years away. Credit: NASA, ESA, R. Sankrit and W. Blair (Johns Hopkins University).

In its 4.5 billion year history, Earth has had to run the gauntlet. Numerous catastrophes have imperilled the planet, from massive impacts, to volcanic conflagrations, to frigid episodes of snowball Earth. Yet life persists.

Among all of the hazards that threaten a planet, the most potentially calamitous might be a nearby star exploding as a supernova.