Dark oxygen collected from the sea floor

Something dark and metallic-like is pumping out large amounts of oxygen from the bottom of the Pacific Ocean, at depths where a lack of sunlight makes photosynthesis impossible, scientists have noticed.

The find has surprised scientists and the source remains a mystery. The oxygen might be generated by metal-rich mineral deposits, some sort of metallic substance or nodules, they claim.

To researchers’ surprise, they measured voltages of up to 0.95 volts across the surface of the nodules. It is possible that the nodules catalyse the splitting of water into oxygen and hydrogen, but more experiments are needed.

The scientists also say this new discovery could change everything about what we know about oxygen itself, and how life as we know it is created.

This challenges what we know about the emergence of life on Earth, researchers say: “When we first got this data, we thought the sensors were faulty, because every study ever done in the deep sea has only seen oxygen being consumed rather than produced,” study lead author Andrew Sweetman, a professor and leader of the seafloor ecology and biogeochemistry research group at the Scottish Association for Marine Science (SAMS)

But when the instruments kept showing the same results, Sweetman and his colleagues knew they “were onto something ground-breaking and unthought-of,” he said.

So what does that mean for deep sea mining? Green Prophet has covered many stories and research to shed light on the problems with deep sea mining and what this could do to delicate, deep sea ecosystems.

Dr. Paul Johnston, from Greenpeace’s Science Unit, says, “This study shows that processes are going on in the deep sea and which are associated with these mineral nodules that we are only just becoming aware of. The ecological importance of this process as a source of oxygen in deep-sea environments is not really known but may be highly important.

“We should impose a moratorium on exploiting these systems because we still lack a comprehensive understanding not only of their biodiversity, but also of the complex ecological functions they support.”

Scientists are joining in the call to protect the deep seabed from mining as the International Seabed Authority in Jamaica this week to decide the future of the deep sea mining industry. 

The post What is dark oxygen? appeared first on Green Prophet.

The Jewish version of Arbor Day Tu B’Shevat is more relevant today than ever. Transformed from a general agricultural holiday into a dedicated arboreal conservation initiative in the early 1900’s, this celebration takes place towards the end of January during the Hebrew month of Shevat.

This holiday addresses the travesty that trees previously revered by indigenous people around the globe have become nothing more than commodities in our modern consciousness, something to be grown, skinned, chopped and used in building projects.

But there are so many other reasons to value trees. Not only are they beautiful sentries that transform a flat and dusty landscape, and gracious hosts of important bugs, birds and sometimes mammals too, they also perform a variety of crucial environmental services that most of us don’t see. Followed is a list of five.

1. Trees Absorb Carbon Dioxide

It is relatively well known that trees absorb carbon dioxide. This environmental service also known as a “carbon sink” has become better understood as the discussion about climate change has gained momentum. Trees capture the same CO2 that is spewed from the exhaust of a car and factories and store it in their roots, bark and leaves, diverting harmful emissions from the atmosphere. If it weren’t for trees, life on earth would be significantly hotter, and yet in the last few decades we have managed to decrease forest cover by more the half. Researchers at the World Resources Institute predict that global demand for wood will double by 2050, putting trees (and therefore us) at deadly risk.

2. Trees Help Us Breathe

In addition to sucking up the pollution we unleash, trees produce the oxygen that we need to breathe. According to a website devoted to forestry, one tree produce the same amount of oxygen in one season that ten humans use in an entire year. And why does oxygen matter? Consider this: if we cut off the supply of oxygen to the brain for just a fraction of a second, we start to lose consciousness. In the prolonged absence of oxygen, we will experience respiratory failure and even death.

3. Trees Clean the Soil and Scrub the Air

In addition to absorbing CO2 and using it for food, trees scrub harmful pollutants from both the soil and the air. Remarkably resilient in the face of our pollutant blitz, they absorb pollutants in the soil and either store them or convert them into something useful and treat air pollutants in a similar manner. A world without trees would be hotter and smoggier.

4. Trees Prevent Water Runoff

As climate change escalates, global sea levels are expected to rise as much as 6.5 feet by 2100, according to the National Geographic, though some scientists believe that if the Greenland ice sheet melts, seas could rise 23 feet. If this happens, London and Los Angeles will vanish. In less dramatic circumstances, trees can absorb water runoff and prevent flash floods from destroying crops, homes and soil erosion. One Colorado Blue Spruce can absorb as much as 1,000 gallons of water, according to forestry experts.

5. Trees Block Wind and Noise

Have you ever driven down a busy highway with houses on either side of it and noticed some homeowners have planted either one or two rows of tall trees along the length of their property? Here’s the trifold logic behind such a choice: trees create a natural boundary and provide some privacy, but they also ward off noise pollution and act as a windbreaker. The latter quality can reduce heating bills by up to 30 percent and reduce snow drifts in northern latitudes.

We have barely skimmed the importance of trees in this post and not one of them has anything to do with profit; suffice to say that life without trees is no kind of life at all. So go plant one or two or three this Tu B’Shevat; your very existence is directly tied to theirs.

The post 5 reasons to love Trees on Tu B’Shevat appeared first on Green Prophet.

As sulfur cycles through Earth’s atmosphere, oceans and land, it undergoes chemical changes that are often coupled to changes in other such elements as carbon and oxygen. Although this affects the concentration of free oxygen, sulfur has traditionally been portrayed as a secondary factor in regulating atmospheric oxygen, with most of the heavy lifting done by carbon. However, new findings that appeared recently in Science suggest that sulfur’s role may have been underestimated.

Itay Halevy from the Weizmann Institute in Israel with Shanan Peters of the University of Wisconsin and Woodward Fischer of the California Institute of Technology, were interested in better understanding the global sulfur cycle over the last 550 million years – roughly the period in which oxygen has been at its present atmospheric level of around 20%.

They used a database developed and maintained by Peters at the University of Wisconsin, called Macrostrat, which contains detailed information on thousands of rock units in North America and beyond.

The researchers used the database to trace one of the ways in which sulfur exits ocean water into the underlying sediments – the formation of so-called sulfate evaporite minerals.

These sulfur-bearing minerals, such as gypsum, settle to the bottom of shallow seas as seawater evaporates. The team found that the formation and burial of sulfate evaporites were highly variable over the last 550 million years, due to changes in shallow sea area, the latitude of ancient continents and sea level.

More surprising to Halevy and colleagues was the discovery that only a relatively small fraction of the sulfur cycling through the oceans has exited seawater in this way. Their research showed that the formation and burial of a second sulfur-bearing mineral – pyrite – has apparently been much more important.

Pyrite is an iron-sulfur mineral (also known as fools’ gold), which forms when microbes in seafloor sediments use the sulfur dissolved in seawater to digest organic matter. The microbes take up sulfur in the form of sulfate (bound to four oxygen atoms) and release it as sulfide (with no oxygen).

Oxygen is released during this process, thus making it a source of oxygen in the air. But because this part of the sulfur cycle was thought be minor in comparison to sulfate evaporite burial (which does not release oxygen), its effect on oxygen levels was also thought to be unimportant.

In testing various theoretical models of the sulfur cycle against the Macrostrat data, the team realized that the production and burial of pyrite has been much more significant than previously thought, accounting for more than 80% of all sulfur removed from the ocean (rather than the 30-40% in prior estimates).

As opposed to the variability they saw for sulfate evaporite burial, pyrite burial has been relatively stable throughout the period.

The analysis also revealed that most of the sulfur entering the ocean washed in from the weathering of pyrite exposed on land. In other words, there is a balance between pyrite formation and burial, which releases oxygen, and the weathering of pyrite on land, which consumes it. The implication of these findings is that the sulfur cycle regulates the atmospheric concentration of oxygen more strongly than previously appreciated.

“This is the first use of Macrostrat to quantify chemical fluxes in the Earth system,” said Peters. “I met my coauthors at a lecture I gave at Caltech, and we immediately began discussing how we might apply Macrostrat to understanding biogeochemical cycling. I think this study will open the door to many more uses of Macrostrat for constraining biogeochemical cycles.”

“For me, the truly surprising result is that pyrite weathering and burial appear to be such important processes in the sulfur cycle throughout all of Earth’s history. The carbon cycle is recognized as the central hub controlling redox processes on Earth, but our work suggests that nearly as many electrons are shuttled through the sulfur cycle,” said Fischer.

Halevy: “These findings, in addition to shedding new light on the role of sulfur in regulating oxygen levels in the atmosphere, represent an important step forward in developing a quantitative, mechanistic understanding of the processes governing the global sulfur cycle.”

Image of Fool’s gold from Shutterstock

The post Fool’s Gold Regulates Our World’s Oxygen Supply appeared first on Green Prophet.