Tag Archives: subterranean

The power of subterranean pressure is reshaping the Earth’s inner core.

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Diagram showing the inner structure of the Earth

Rostislav Zatonskiy/Alamy

The inner core of Earth’s solids appears to have changed shape over the last 20 years or so, according to seismic wave measurements, but the behavior of these waves can also be explained by other shifts at the center of the planet.

Since the 1990s, models and earthquake measurements have shown that the inner core of Earth’s iron nickel moves at its own pace. Over decades, the inner core rotation is faster, slower than other planets, affecting the length of the day and more.

These rotational changes are primarily due to magnetic forces produced by convection in the Earth’s liquid outer core, they say. John Vidale At the University of Southern California. “That flow constantly torques the inner core.”

These magnetic forces, or related processes, can change the shape of the inner core and its rotation. In fact, previous measurements of seismic waves passing through the center of the planet seem to show just that. However, uncertainty regarding the rotation of the core made it impossible to distinguish between rotational changes and shape changes.

Now, Vidale and his colleagues are analyzing seismic waves generated by 128 earthquakes off the coast of South America between 1991 and 2023. All waves were measured by Alaskan instruments after passing through the planet.

From these, researchers have identified 168 sets of seismic waves that have passed through or near the same area of ​​the inner core, but have been away for years. It was only possible to identify these matches Recent work Vidale says it will better constrain the variation in rotation of the inner core.

Both waves of each pair that did not pass through the inner core shared a similar pattern, suggesting that in the region within the planet nothing had changed between the first and second earthquakes. Masu. However, the waves of the pair crossed with the inner core did not match.

Researchers say this suggests that the inner core not only slows down and speeds up rotation for decades but also changes shape. They say that these changes are magnetically pulled at the less viscous edge of the inner core of the solid or interaction between the inner core and the structure of the planetary core and the lower mantle. They say it is likely caused by interactions between the layers. The crust.

hrvojetkalčić At Australian National University, which was not involved in the study, this is a “step” to resolve changes in the internal core beyond rotation. However, he says that the shape change is not the only explanation for the seismic waves of incongruity.

As Vidale and his colleagues acknowledge, these differences can also be caused by unrelated changes in the outer core, convection within the inner core itself, or by eruption of melted material from the inner core. There is. “It’s really hard to tell,” Bidal says. He suggests that studying more repeated earthquakes in the future will help identify changes in more detail.

Tkalčić says seismological measurements in remote areas such as the seabed are also useful. “This is important for understanding the deepest inner evolution of Earth, from the time of the planetary layers to the present,” he says.

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Source: www.newscientist.com

NASA to investigate subterranean ocean of Uranus’ moon

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Some of the icy moons in the Jupiter and Saturn systems appear to have oceans of liquid water inside them. Although our knowledge of Uranus' moons is more limited, future tours of the Uranian system may be able to detect subsurface oceans. To plan for this, we need to understand how the internal structure of satellites, with and without oceans, relates to observable quantities. New research from the University of Texas Geophysical Institute and the University of California, Santa Cruz shows it may be possible to diagnose the presence or absence of liquid water oceans inside some of Uranus' moons, including Miranda and Ariel. There is, Umbriel, and it is thought that this, combined with measurements of the gravitational field, may provide comprehensive constraints on the internal structure and history of Uranus' moons.

Uranus' four major moons, Ariel, Umbriel, Titania, and Oberon, may have oceanic layers. Salty seas, or salty seas, are found beneath the ice and above water-rich and dry rock layers. Miranda is too small to retain enough heat in the ocean layer. Image credit: NASA/JPL-Caltech.

When NASA's Voyager 2 flew by Uranus in 1986, it took grainy photos of the large icy moon.

Now, NASA plans to send another spacecraft to Uranus, this time equipped to see if those icy moons hide oceans of liquid water.

The mission is still in the early planning stages, but planetary researchers are preparing by building a new computer model that can be used to detect oceans beneath the ice using only the rover's cameras.

Their computer model works by analyzing the moon's tiny vibrations, or wobbles, as it orbits its parent planet.

From there, you can calculate how much water, ice, and rock is inside. A small wobble means the moon is mostly solid, while a large wobble means its icy surface is floating in an ocean of liquid water.

When combined with gravity data, the model calculates the depth of the ocean and the thickness of the overlying ice.

Dr. Doug Hemingway, a planetary scientist at the University of Texas Geophysical Institute, said: “If we find that Uranus' moons have an inland ocean, it means there are a huge number of potentially habitable worlds across the galaxy. It may mean,” he said.

“The discovery of oceans of liquid water on Uranus' moons will change our thinking about the range of possibilities for life.”

All large moons of the solar system, including the moons of Uranus, are tidally locked.

This means that the same side always faces the parent planet while orbiting, as the gravity matches their rotation.

However, this does not mean that the satellite's rotation is completely fixed; all tidally locked satellites will oscillate back and forth during their orbit.

Determining the extent of the wobble is key to learning whether Uranus' moons have oceans, and if so, how large.

A satellite with an ocean of liquid water splashing inside will wobble more than one that is entirely solid. However, even the largest oceans experience only small wobbles. The moon's rotation can shift by just a few hundred feet as it passes through its orbit.

This is still enough for a passing spacecraft to detect it. In fact, this technique was previously used to confirm that Saturn's moon Enceladus has an internal ocean.

To find out whether the same technique would work on Uranus, Dr. Hemingway and his colleague Dr. Francis Nimmo of the University of California, Santa Cruz performed theoretical calculations on Uranus's five moons, using a variety of the most I came up with a plausible scenario.

Detecting smaller oceans means the spacecraft will need to get closer or carry more powerful cameras.

“The next step is to extend the model to include measurements from other instruments and see how this improves the interior of the satellite,” Dr. Hemingway said.

of the team work Published in a magazine Geophysical Research Letters.

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DJ Hemingway and F. Nemo. 2024. Search for the underground ocean inside Uranus's moon using balance and gravity. Geophysical Research Letters 51 (18): e2024GL110409;doi: 10.1029/2024GL110409

This article is a version of a press release provided by the University of Texas.

Source: www.sci.news

Unusual Occurrences Unfolding in Italy’s Subterranean Volcano

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The Flegraean Fields (also known as Campi Flegrei in Italian) are active volcanic fields near Naples, Italy. Unlike nearby Mount Vesuvius, Campi Flegrei does not have a single volcano. It is rather a volcanic system, with several centers located within sunken areas called calderas (essentially deep sinkholes or cauldrons).

Campi Flegrei is surrounded by suburbs and densely populated areas near the city of Pozzuoli. After a period of relative quiet and peace for the past 40 years, things began to change in September 2023.

Earthquakes began to be felt in Campi Flegrei in September 2023. Since then, more than 1,100 earthquakes have been recorded, some reaching 4.2 on the Richter scale. This caused the height of the ground to change. It is a process known as “Gradual earthquake“. The region has been affected by this phenomenon before, most recently from 1968 to 1972 and then again from 1982 to 1984.

Gradual earthquakes can cause the Earth’s surface to rise or fall when magma chambers buried 3 to 4 kilometers deep fill and empty in cycles of uplift and subsidence. This process causes the earthquakes felt by residents here.

However, the people who live here do not care about it, thinking that it is the “breath of the volcano” that lies beneath their eyes. Still, volcanologists have been studying calderas to predict what will happen in the future to avoid potential disasters.

Pisciarelli fumarole

Gases and steam are released from the Pisciarelli fumarole in Pozzuoli, Naples.Photo credit: Luigi Avantaggiato

fumaroles such as Pisciarelli fumarole, a vent on the earth’s surface that releases steam and hot volcanic gases such as sulfur dioxide and carbon dioxide. These can occur as holes, cracks, and fissures near active volcanoes or in areas where magma has risen into the Earth’s crust without erupting.

temple of serapis

The Temple of Serapis, a Roman market building in the Italian city of Pozzuoli, is surrounded by more modern buildings. Photo credit: Luigi Avantaggiato

The Temple of Serapis in Pozzuoli (which was a market building rather than a temple) is considered an emblematic monument of the Campi Flegrei region. It is a symbol of volcanic gradual earthquakes in this region. The ground beneath the surface is either rising or sinking, so it can be completely dry or half submerged in seawater.

The study of slow earthquakes over the past centuries has been made possible thanks to observations such as those made on the ruins of this Roman building. For example, by studying holes drilled into ancient columns by marine molluscs over centuries, scientists can study changes in sea levels at this site.

Source: www.sciencefocus.com

Researchers chart extensive subterranean microbial world

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Professor Magdalena Osburn removed the samples during a site visit in August.

A former gold mine serves as a gateway to explore microbes deep within the Earth’s crust. If you add up the mass of all the microorganisms that live beneath the Earth’s surface, their combined biomass exceeds the biomass of all life in the oceans. However, because of the difficulty of accessing these depths, this myriad of subterranean organisms remains largely unexplored and poorly understood. Using a repurposed gold mine in the Black Hills of South Dakota as a laboratory, Northwestern University researchers have created the most comprehensive map yet of the elusive and rare microbes that live beneath our feet. In total, the researchers characterized nearly 600 microbial genomes, some of which were new to science. Within this group, most microbes fit into one of two categories, said Magdalena Osburn, a Northwestern geoscientist who led the study. And “maximalists” are ready to greedily grab any resources that may come their way. This study was recently published in the journal environmental microbiology.

This new research not only expands our knowledge of the microbes that live deep underground, but also hints at potential life that may one day be discovered underground. Mars. Because microbes rely on resources in rocks and water that are physically distant from the surface, these organisms could survive buried in Mars’ dusty red depths. “The deep underground biosphere is huge. It’s just a huge space,” said Osburn, an associate professor of Earth and planetary sciences in Northwestern University’s Weinberg College of Arts and Sciences. “We used the mine as a conduit to access a biosphere that is difficult to reach no matter how we approach it. A lot of that comes from understudied groups. DNA, you can understand what kind of creatures live underground and find out what they do. These are organisms that we cannot grow in the laboratory or study in more traditional settings. They are often referred to as “microbial dark matter” because we know so little about them.

For the past 10 years, Osburn and his students have been regularly visiting the former Homestake Mine in Reed, South Dakota, collecting geochemical and microbial samples.Now Sanford Underground Research Facility (SURF)’s deep underground laboratory is home to numerous research experiments across a variety of fields. In 2015, Osburn established his six proving grounds. Mine Deep Microbial Observatorythroughout SURF.

Back in Osburn’s lab at Northwestern University, she and her team sequenced the DNA of the microorganisms held within the samples. Of the approximately 600 genomes characterized, microorganisms represented 50 different phyla and 18 candidate phyla. Osburn discovered that within this diverse microbial community, each lineage, at some point, gravitates toward a life-defining trajectory: becoming a minimalist or a maximalist.
“Some of these strains don’t even have the genes to make their own lipids, which is shocking,” Osburn said. “Because how can you make cells without fat? It’s like humans can’t make all the amino acids. Therefore, by consuming protein, amino acid Something we can’t create on our own. But this is on a more extreme scale. Minimalists are the ultimate specialists and we all work together. There’s a lot to share and no duplicate work

Osburn said these underground microbes may provide clues to what might exist elsewhere as we imagine life beyond Earth. “It’s really exciting to see evidence of microbes operating without us, without plants, without oxygen, without surface atmosphere,” she said. “It’s very likely that this kind of life currently exists deep on Mars or in the icy moon’s oceans. The forms of life tell us what lives elsewhere in the solar system.”
And they also affect our own planet. For example, as industry looks for long-term storage for carbon, many companies are exploring the possibility of injecting it deep underground. As we consider those options, Osburn reminds us not to forget the microbiome.

Reference: “A Metagenomic View of New Microbial and Metabolic Diversity Discovered in the Earth’s Deep Biosphere in DeMMO: Microbial Observatory in South Dakota, USA” by Lily Momper, Caitlin P. Casar, and Magdalena R. Osburn, 2023. November 14th, environmental microbiology.DOI: 10.1111/1462-2920.16543 This research was supported by NASA Exobiology (grant numbers NNH14ZDA001N, NNX15AM086), the David and Lucille Packard Foundation, and the Canadian Institute for the Advancement of Research—Earth 4D.

Source: scitechdaily.com