Clare Kenyon
2022 was a rockin’ good year for geology.
From mysteries deep within the Earth’s interior to a future supercontinent, here are five ways geology rocked our world this year.
Looking deep down into history
How do you look into Earth’s past?
You look down.
Deeper.
Right down into the bowels of Earth, where seismic waves stutter to a crawling pace.
New research using seismological and mathematical geophysical methods shows these “ultra-low velocity zones” (ULVZs) have a composition starkly different to the surrounding material.
This may hint at a violent event in Earth’s nascent history, more than 4.4 billion years ago, when a Mars-sized object smashed into Earth, creating a magma ocean which eventually cooled, sinking deep into the Earth and carrying rocks, gasses and crystals with it.
Chicken and the egg: oxygen or photosynthesis?
If we fast forward a few hundred million years after the birth of the Earth, we arrive at the sudden (geologically-speaking) introduction of oxygen as a key component of our atmosphere.
Traditionally, the production of oxygen has been linked to the evolution of plants and bacteria, but new research now suggests oxygen was being produced in large amounts well before photosynthesising life forms appeared.
By investigating how crushed basalt, granite and peridotite produce hydrogen peroxide when exposed to water in an oxygen-free environment, researchers at Newcastle University have shown oxygen may have been produced inorganically without the need for plant life, thanks to Earth’s tectonic activities.
The study also suggests oxygen-loving hyperthermophilic bacteria may have had a great role in the evolution of life than previously thought.
Reading the rocks to find the Best Australian Science Writing 2021.
The winner of Best Australian Science Writing 2021, Lauren Fuge, shows how a deep connection with the rocks of the Flinders Ranges in South Australia can unearth geological secrets of climates and tectonic times gone by.
Images of buckled mountains and how they mirror similar strata in far-off continents like North America, are compelling reminders of just how powerful and ancient the forces of Earth are and how little time we humans have spent in it – and how little time we may have left.
Golden Spike to mark the Anthropocene
Having announced its intention to mark the ‘Anthropocene’ in the geological record two years ago, the Anthropocene Working Group (AWG) has nominated the Flinders Reef in Moreton Bay, Queensland, as one of the nine contenders for a Golden Spike.
If chosen, this location will be the second in Australia and the second (out of a total of 81) for the Southern Hemisphere chosen to host a Golden Spike, which traditionally mark the boundaries of different geological layers.
Annual bands incorporated into the coral structures in Flinders Reef trace the surrounding environment (and humankind’s impact on it) right back to the 1700s.
The AWG will be hoping to decide on a location for the Golden Spike to mark the beginning of the Anthropocene by the end of 2022, although a majority of at least 60% will be required.
A future supercontinent
Every 600 million years or so, the Earth’s continents collide to form a supercontinent.
An alien visiting Earth around 200-300 million years ago would see a very different view of the planet from above, with the supercontinent, Pangaea, dominating the surrounding oceans.
In the next 200-300 years, new supercomputer research suggests the weaker oceanic plates of the Pacific Ocean will yield to the creep of continents, closing the Pacific Ocean and forming the next supercontinent.
Dubbed Amasia, the supercontinent will likely have an extremely arid interior with high temperature ranges, while the sea level will be considerably lower.