Earth has a 27.5-million-year 'pulse' of major geological events, says study

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This week:

• Earth has a 27.5-million-year 'pulse' of major geological events, says study
• The worldwide demand for sand
• Maritime startup invents Lego-style bricks made from recycled plastic

Earth has a 27.5-million-year 'pulse' of major geological events, says study

The Earth behaves cyclically, and major geologic events like earthquakes and volcanic eruptions that could lead to extinctions cluster in cycles, a new study has found.

The research team, led by Michael Rampino, a professor in New York University's department of biology, even has a special name for it.

"All of these things, when you add them all together, seem to occur in pulses," said Rampino. "Not at random, but in pulses."

Rampino and his colleagues looked at recently published data about a period of 89 geological events in the past 260 million years in order to identify peaks in which they occurred.

These so-called pulses have a cycle of happening roughly every 27.5 million years.

"It means that there's an ongoing cycle running through all of these various and seemingly unrelated geological events," said Rampino.

The research team analyzed mass geological episodes, such as fluctuations in the global sea level caused by changes in sea-floor spreading rates, that affected sea and land organisms. The extinction of dinosaurs dating back 66 million years or three cycles ago was one of the events the researchers looked at to find a pattern.

The research notes how many of these catastrophic events seem to happen during the same period. Giant earthquakes and volcanic eruptions still happen outside these peaks, and scientists are still unsure what is causing them.

According to the study, the most recent cluster of disastrous geological episodes was about seven to 10 million years ago, so it is safe to say that Earth is at least 15 million years away from experiencing this series of catastrophic events that will likely wipe out most, if not all, humankind.

If you were wondering, human-induced climate change is separate from these cycles, but anything we do to damage the environment will continue to affect our living conditions.

"I don't know what we could do 20 million years from now," said Rampino. "But for now, these cycles don't seem to be in the control of human beings."

Even if humans survive and develop the technology to deal with these events millions of years from now, Rampino said the Earth's pulse will keep on beating.

The geologist said that for a long time, scientists lacked accurate enough age data to make co-ordinated, statistics-based calculations about these geological events.

"Back in the early 20th century, no one had very good evidence to show whether they were cycles or not," said Rampino. "And many or most geologists thought that these cycles were random."

Other research studies have proposed cycles for various geological occurrences on a global scale, like volcanic activity, leading to climate changes.

Rampino himself published studies in the past that looked at the cycle of some of these events separately. In September 2020, his team found the same interval of 27.5 million years in a study about the mass extinction cycle of four-legged land animals.

It was difficult for scientists to perform any quantitative investigations until a couple of years ago. With the improvement of radio-isotope dating techniques and updates in the geologic timescale, new data has been compiled that makes it possible to search for correlations in these events accurately.

Geologists want to know how the Earth behaves, and this evidence shows that the Earth has behaved in a cyclical way for a long time, according to Rampino.

The researcher said this is an important finding because the question isn't why, but how these things happen.

"You need to know the age of these events very precisely," said Rampino. "Now [we] can see there's a periodicity."

Thas Grandisoli

Reader feedback

In response to Emily Chung's story on Canadian swimsuit designers using recycled plastic, Mark Hambridge wrote:

"Of course, the whole swimsuit problem goes away if you use the swimwear we are born with: fits perfectly, lightweight, colour matched so no tan lines, drip, sun or air dry, can be washed with household soap (dry cleaning especially forbidden). Unfortunately, social issues make it difficult to use in urban areas."

Daniel Zung, meanwhile, addressed Colin Butler's story on helium balloons ending up in the Great Lakes. "It is probably best not to be inflating balloons with helium to be released. While apparently the shortage of helium has decreased over the past year, potentially due to fewer parties, once more balloons are demanded, helium prices might rise as demand for the gas returns. Best to keep helium for science and manufacturing where as a society we might have better use of the gas rather than polluting the environment by using balloons (in general)."

Write us atwhatonearth@cbc.ca.

Old issues of What on Earth? are right here.

There's also a radio show and podcast!Protests against old-growth logging in British Columbia have drawn international attention to the importance of ancient forests. This week, What on Earth guest host Lisa Johnson hears about the role these trees play in fighting climate change.What on EarthairsSunday at 12:30 p.m., 1 p.m. in Newfoundland. Subscribe on your favourite podcast app or hear it on demand at CBC Listen.

The Big Picture:Sand mining

In response to a recent story we did on the push to make more environmentally friendly concrete, several readers pointed out the ecological impact of one of concrete's biggest ingredients: sand. Fact: no commodity is mined more than sand. No mineral or metal comes close. Its greatest use is in concrete, but sand can also be found in everything from glass to toothpaste. As countries continue to urbanize, sand use is only expected to go up. While we have deserts that would seem to contain more than enough of the grainy stuff, the sand found in places like the Sahara is so weathered and dry that it is unusable for applications like concrete. Prime sand is found along shorelines (such as the Congo River near Brazzaville, Republic of Congo, as in the photo below). But in meeting the global demand for sand, mining operations are eroding coastlines and destroying ecosystems.

Hot and bothered: Provocative ideas from around the web

• "Heat domes," like the one preying on Western Canada and the U.S., are made more intense by climate change, says this essay in the New York Times.

• Trees play an essential role in regulating the heat in U.S. cities like Houston, where temperatures can reach up to 38 C in the summer. Rich areas have considerably more trees than low-income areas in Houston and other cities. A 2020 study found that neighbourhoods where Black people previously lived and were "redlined" that is, where banks refused to provide loans are at least 3 C warmer today than non-redlined areas.

• The popularity of electric cars in China continues to grow quickly, with sales increasing by 177 per cent this year. The country's best-selling electric car isn't a Tesla, which costs more than $35,000 US there, but rather the domestically made Hong Guang Mini, which starts at around $4,500 US, can reach top speeds of 100 km/h and has a battery range of up to 168 kilometres.

Maritime startup invents Lego-style bricks made from recycled plastic

In a social media video shot in a shipping container in his backyard, Dustin Bowers can be seen wearing protective goggles and throwing plastic garbage into a funnel that grinds it up into shreds.

From these shreds, the Hampstead, N.B.-based founder and product developer of PLAEX Building Systems Inc. has created a no-cut, mortarless and reusable system of interconnecting bricks and finish panels basically Lego for real-life structures.

Bowers is a carpenter from a family of tradespeople. But after a few years managing multimillion-dollar construction projects out west, he said he could no longer ignore the "insane" amount of waste it generates.

"If we keep doing this, there ain't going to be a planet for our kids."

Producing PLAEX uses less energy than current recycling methods and very little water, all of which helps lessen its ecological impact, said Bowers.

He first came up with the idea in 2017 and has developed a prototype that is being tested for Canadian Standards Association (CSA) approval and should be ready for purchase orders by August.

Although the product will initially only be certified for use in non-occupied structures such as retaining walls, flood walls, garages and sheds eventually he hopes to have it approved for building houses.

When it came to securing a reliable source of plastic waste, Bowers saw another problem he could tackle. He has experience in market gardening and knows how integral plastic is in even the most eco-conscious farm and garden practices.

"A lot of farmers have to bribe their garbage man to get rid of it," he said. "It's a problem."

He reached out to David Wolpin, who runs a farm supply company in Bloomfield, N.B.

Wolpin supplies farms with plastic for row cover, ground cover, insect netting, greenhouses and irrigation, among other things.

"I said, 'Well, actually, I can help you set up your whole supply chain,'" said Wolpin. "'Basically, if you take all the stuff that I sell a few years after I sell it, you're in business.'"

Raised by "recovering hippies," Wolpin said the fact that he sells tonnes of plastic every year weighs on his conscience. Most of that plastic is used for between three and 10 years.

Ultimately, he said, he feels great about supporting local producers they help reduce carbon emissions from importing food and keep food dollars in the local economy. The plastic he sells helps them extend the local growing season and reduces the use of toxic pesticides by discouraging weed growth and pest damage.

Wolpin is working with Bowers on a Maritime-wide plastic waste collection service for farmers.

Green building expert Keith Robertson of Solterre Design in Halifax thinks PLAEX is innovative in a Canadian context, and likes that it tackles waste in two ways.

First, he said, it diverts plastic from the landfill, where it has been a big problem for municipal waste management.

Secondly, if the Lego-like, no-cut system can eliminate or even greatly reduce construction waste, "it's a big plus."

Rose Murphy

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