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A tectonic plate may have split apart, pulling Europe toward Canada
Geologists may have spotted evidence of the beginning stages of a subduction zone, a process that drives the movement of Earth's tectonic plates.
- Geologists have long puzzled over a flat, featureless region off the coast of Portugal that's been the location of several earthquakes.
- A team may have confirmed that a drip-shaped mass, buried 155 miles below the seafloor, might be responsible for the seismic activity.
- If confirmed, the drip-shaped anomaly also suggests that geologists have for the first time observed the early stages of a subduction zone.
Since 1969, some geologists have been puzzled by a 7.9-magnitude earthquake struck off the coast of Portugal. What was peculiar was the location of the epicenter: a flat, featureless section of seabed. Normally, you'd expect to see faults, underwater mountains, or other signs of tectonic activity near the site of such a powerful earthquake.
Now, a team of geologists may have the explanation: Buried 155 miles below the seafloor near Portugal is a massive drip-like shape anomaly that seems to have been formed when the bottom of a tectonic plate began peeling away from its top.
At the European Geosciences Union meeting in April, the team suggested the findings could represent the beginnings of a baby subduction zone. It would be the first time scientists have ever directly observed such activity within tectonic plates, and the findings would also suggest that Europe is in the early stages of a centimeters-per-year tectonic voyage to Canada.
"It's a big statement," marine geologist João Duarte told National Geographic, which on May 6 published a story on the findings. "Maybe this is not the solution to all the problems. But I think we have something new here."
He added that how exactly subduction zones form is one of the biggest unsolved mysteries in plate tectonics. For the most part, geologists only observed new subduction in places where there's ongoing subduction.
"Most of what we know so far is that new subduction tends to stay in the places where we already have ongoing subduction," Fabio Crameri, a Geodynamic modeller who attended the EGU lecture, told National Geographic. "But that doesn't mean it won't happen."
KDS4444 via Wikipedia
Interestingly, several geologists over the decades have theorized that a drip-shaped mass might exist some 155 miles below the surface. In 1975, geologist Michael Purdy even generated an image that looks strikingly similar to the recent findings. In 2012, a team was able to identify the mass by using seismic waves. And in 2018, a team used 3D teleseismic P-wave tomographyP-wave tomography technology to examine the anomaly once again.
To figure out why earthquakes were occurring this strange mass, and to test the hypothesis that the mass was caused by the bottom of a tectonic plate peeling away from its top, Duarte and his colleagues created numerical models.
"The key, [Duarte] says, likely lies in an seemingly innocuous layer in the middle of the tectonic plate," wrote Maya Wei-Haas for National Geographic. "Past work suggested that water percolating through the ocean plate's web of fractures had reacted with the rocks below the surface, transforming them into soft green minerals in a process known as serpentinization. Perhaps this layer provided just enough weakness to allow the denser bottom of the plate to peel away. Scientists believe tectonic peeling may be common under thick continental plates through a slightly different mechanism, and possibly even in old subduction zones, but it has never been documented before in pristine oceanic plates."
Duarte's team said the findings, if confirmed, would help geologists better understand how Earth's tectonic plates interact.
"The identification of a first case of oceanic lithospheric delamination will certainly contribute to further our understanding of the dynamics of tectonic plates," they wrote in a recent paper. "Old oceanic lithosphere may be prone to gravitational instabilities, which may play a fundamental role in the process of subduction initiation."
This storm rained electrons, shifted energy from the sun's rays to the magnetosphere, and went unnoticed for a long time.
- An international team of scientists has confirmed the existence of a "space hurricane" seven years ago.
- The storm formed in the magnetosphere above the North magnetic pole.
- The storm posed to risk to life on Earth, though it might have interfered with some electronics.
What do you call that kind of storm when it forms over the Arctic ocean?<iframe width="730" height="430" src="https://www.youtube.com/embed/8GqnzBJkWcw" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe><p> Many objects in space, like Earth, the Sun, most of the planets, and even some large moons, have magnetic fields. The area around these objects which is affected by these fields is known as the magnetosphere.</p><p>For us Earthlings, the magnetosphere is what protects us from the most intense cosmic radiation and keeps the solar wind from affecting our atmosphere. When charged particles interact with it, we see the aurora. Its fluctuations lead to changes in what is known as "space weather," which can impact electronics. </p><p>This "space hurricane," as the scientists are calling it, was formed by the interactions between Earth's magnetosphere and the <a href="https://en.wikipedia.org/wiki/Interplanetary_magnetic_field" target="_blank" rel="noopener noreferrer">interplanetary magnetic field,</a> the part of the sun's magnetosphere that goes out into the solar system. It took on the familiar shape of a cyclone as it followed magnetic fields. For example, the study's authors note that the numerous arms traced out the "footprints of the reconnected magnetic field lines." It rotated counter-clockwise with a speed of nearly 7,000 feet per second. The eye, of course, was still and <a href="https://www.sciencealert.com/for-the-first-time-a-plasma-hurricane-has-been-detected-in-space" target="_blank" rel="noopener noreferrer">calm</a>.</p><p>The storm, which was invisible to the naked eye, rained electrons and shifted energy from space into the ionosphere. It seems as though such a thing can only form under calm situations when large amounts of energy are moving between the solar wind and the upper <a href="https://www.reading.ac.uk/news-and-events/releases/PR854520.aspx" target="_blank">atmosphere</a>. These conditions were modeled by the scientists using 3-D <a href="https://www.nature.com/articles/s41467-021-21459-y#Sec10" target="_blank">imaging</a>.<br><br>Co-author Larry Lyons of UCLA explained the process of putting the data together to form the models to <a href="https://www.nbcnews.com/science/space/space-hurricane-rained-electrons-observed-first-time-rcna328" target="_blank">NBC</a>:<br><br>"We had various instruments measuring various things at different times, so it wasn't like we took a big picture and could see it. The really fun thing about this type of work is that we had to piece together bits of information and put together the whole picture."<br><br>He further mentioned that these findings were completely unexpected and that nobody that even theorized a thing like this could exist. <br></p><p>While this storm wasn't a threat to any life on Earth, a storm like this could have noticeable effects on space weather. This study suggests that this could have several effects, including "increased satellite drag, disturbances in High Frequency (HF) radio communications, and increased errors in over-the-horizon radar location, satellite navigation, and communication systems."</p><p>The authors <a href="https://www.nature.com/articles/s41467-021-21459-y#Sec8" target="_blank" rel="noopener noreferrer">speculate</a> that these "space hurricanes" could also exist in the magnetospheres of other planets.</p><p>Lead author Professor Qing-He Zhang of Shandong University discussed how these findings will influence our understanding of the magnetosphere and its changes with <a href="https://www.eurekalert.org/pub_releases/2021-03/uor-sho030221.php" target="_blank" rel="noopener noreferrer">EurekaAlert</a>:</p><p>"This study suggests that there are still existing local intense geomagnetic disturbance and energy depositions which is comparable to that during super storms. This will update our understanding of the solar wind-magnetosphere-ionosphere coupling process under extremely quiet geomagnetic conditions."</p>
Research reveals a new evolutionary feature that separates humans from other primates.
- Researchers find a new feature of human evolution.
- Humans have evolved to use less water per day than other primates.
- The nose is one of the factors that allows humans to be water efficient.
A model of water turnover for humans and chimpanzees who have similar fat free mass and body water pools.
Credit: Current Biology
Being skeptical isn't just about being contrarian. It's about asking the right questions of ourselves and others to gain understanding.
- It's not always easy to tell the difference between objective truth and what we believe to be true. Separating facts from opinions, according to skeptic Michael Shermer, theoretical physicist Lawrence Krauss, and others, requires research, self-reflection, and time.
- Recognizing your own biases and those of others, avoiding echo chambers, actively seeking out opposing voices, and asking smart, testable questions are a few of the ways that skepticism can be a useful tool for learning and growth.
- As Derren Brown points out, being "skeptical of skepticism" can also lead to interesting revelations and teach us new things about ourselves and our psychology.