Russia: Earthquake Of Magnitude 6.0 Strikes Off Kamchatka Peninsula

An Earthquake of magnitude 6.0 strikes off Kamchatka Peninsula in Russia’s Far East on Friday. No damage have been reported after the quake shook the Kamchatka Peninsula. The tremor struck 58 miles east of Ozernovskiy at about 1.40am on Friday morning.

The city is located in the far east of Russia, which lies on the Pacific coast.

No tsunami warnings have been issued.

Seismologists Use Massive Earthquakes To Unlock Secrets Of The Outer Core

By applying new data and Princeton’s supercomputers to the classic question of what lies beneath our feet, Princeton seismologist Jessica Irving and an international team of colleagues have developed a new model for the Earth’s outer core, a liquid iron region deep in the Earth.

The outer core is churning constantly, sustaining the planet’s magnetic field and providing heat to the mantle. “Understanding the outer core is crucial for understanding the history of the magnetic field,” said Irving, an assistant professor of geosciences. Her team’s work appears today in the journal Science Advances.

“The model we have produced, EPOC—Elastic Parameters of the Outer Core—is going to be the background model, the one thing that underlies everything else,” said Irving. The researchers describe EPOC as an outer core update of the existing Preliminary Earth Reference Model (PREM), a model of how fundamental Earth properties vary with depth, which was developed almost 40 years ago.

The key data in the research came from “normal modes,” which are standing waves that can be measured after the very largest earthquakes, typically magnitude 7.5 or higher. Unlike the body waves and surface waves that most seismologists study, normal modes are “the vibration of the whole Earth at once, which is kind of an amazing thing to think about,” Irving said. “We could say that the Earth ‘rings like a bell,’ at characteristic frequencies.”

The new model, EPOC, was first envisioned at a four-week summer science workshop where Irving was housed with fellow seismologists Sanne Cottaar, at the University of Cambridge, and Vedran Leki?, at the University of Maryland-College Park.

“PREM is a venerable, very simple, well-regarded model, but it can’t represent any small-scale structures,” Irving said. “We thought, ‘Can we make a simple model, with even fewer parameters than PREM, that does the job just as well?’ It turned out we could make a model that does the job much better.”

For one, EPOC reduces the need for a “complicated little layer” at the boundary between the core and the mantle, she said. Researchers in recent decades had found discrepancies between the PREM-predicted body wave velocity and the data they were finding, especially at the top of the core, and some had argued that there must be an anomalously slow layer hidden there. They debated how thick it should be—estimates range from 50 to 300 miles—and exactly what it must be composed of.

Her team’s model doesn’t offer any more specifics than PREM, Irving said, “but we suggest that because EPOC fits the data better, maybe you don’t need this little layer.” And additionally, it provides information about the material properties of the outer core.

The outer core is vitally important to the thermal history of the planet and its magnetic field, said Irving, but “it’s not tangible. We can’t show you a rock from the outer core. But at the same time, it is such a huge section of our planet. The core has roughly 30 percent of the mass of the planet in it. The crust is insignificant by comparison. There is so much that we don’t understand about the deep earth—and these aren’t even the complicated properties. We’re just looking for the very slowly varying bulk properties.”

To create their model, Irving and fellow seismologists pooled their skills. Cottaar had experience with equations of state—the physics explaining the connections between temperature, pressure, volume and other fundamental characteristics—and Leki? was fluent in Bayesian techniques, a probabilistic approach that helped the team sift through countless possible models and find the most likely ones. And because of her background with normal mode seismology, Irving knew how to work with the newly updated dataset.

“So all three of us were seismologists with different specialized skill sets, and we liked to have coffee at breakfast together,” Irving said. “It’s so much fun doing science with friends.”

The researchers fed the equations of state into Princeton’s Tiger supercomputer cluster to generate millions of possible models of the outer core. “Every six seconds we created a new model,” Irving said. “Some we rejected because they looked wrong. We have scientific tests for ‘wrong,’ for models that say things like, ‘The mass of the Earth should be twice what we think it is.'”

The team then took the best of the models and used them to predict what frequencies the whole Earth would shake at after a massive earthquake. The researchers compared the measured frequencies of normal modes to the predictions from their models until they found their preferred model.

When teaching about normal modes, Irving uses the metaphor of two bells, one of brass and one of steel, both painted white. “If you hit those bells, you’ll get different notes out of them, and that will tell you that you have different materials in there,” she said. “The exact frequencies—the exact pitch that the Earth at shakes after these very large earthquakes—depends on the material properties of the Earth. Just like we can’t see through the paint on the bells, we can’t see through the planet, but we can listen for the pitch, the frequencies of these whole-Earth observations, and use them to make inferences about what’s going on deep in the Earth.”

Study Yields A New Scale Of Earthquake Understanding

CHAMPAIGN, Ill. — Nanoscale knowledge of the relationships between water, friction and mineral chemistry could lead to a better understanding of earthquake dynamics, researchers said in a new study. Engineers at the University of Illinois at Urbana-Champaign used microscopic friction measurements to confirm that, under the right conditions, some rocks can dissolve and may cause faults to slip.

The study, published in the journal Nature Communications, closely examines how water and calcite – a mineral that is very common in the Earth’s crust – interact at various pressures and groundwater compositions to influence frictional forces along faults.

“Water is everywhere in these systems,” said Rosa Espinosa-Marzal, a civil and environmental engineering professor and co-author of the study. “There is water on the surface of minerals and in the pore spaces between mineral grains in rocks. This is especially true with calcite-containing rocks because of water’s affinity to the mineral.”

According to the researchers, other studies have correlated the presence of water with fault movement and earthquakes, but the exact mechanism remained elusive. This observation is particularly prevalent in areas where fracking operations are taking place – a process that involves a lot of water.

The study focuses on calcite-rich rocks in the presence of brine – naturally occurring salty groundwater – along fault surfaces. The rock surfaces that slide past each other along faults are not smooth. The researchers zoomed in on the naturally occurring tiny imperfections or unevenness on rocks’ surfaces, called asperities, at which friction and wear originate when the two surfaces slide past each other.

“The chemical and physical properties of faulted rocks and mechanical conditions in these systems are variable and complex, making it difficult to take every detail into account when trying to answer these types of questions,” Espinosa-Marzal said. “So, to help understand water’s role in fault dynamics, we looked at a scaled-down, simplified model by examining single asperities on individual calcite crystals.”

For the experiments, the team submerged calcite crystals in brine solutions at various concentrations and subjected them to different pressures to simulate a natural fault setting. Once the crystals were in equilibrium with the solution, they used an atomic force microscope to drag a tiny arm with a silicon tip – to simulate the asperity – across the crystal to measure changes in friction.

In most of the experiments, the researchers first found what they expected: As the pressure applied on the crystals increased, it became more difficult to drag the tip across the crystal’s surface. However, when they increased pressure to a certain point and the tip was moved slowly enough, the tip began to slide more easily across the crystal.

“This tells us that something has happened to this tiny asperity under higher pressures that caused a decrease in friction,” said graduate student and co-author Yijue Diao. “The atomic force microscope also allows us to image the crystal surface, and we can see that the groove increased in size, confirming that calcite had dissolved under pressure. The dissolved mineral and water acted as a good lubricant, thereby causing the observed weakening of the single-asperity contact.”

“This shows that studies such as these warrant serious consideration in future work,” Espinosa-Marzal said. The researchers acknowledge that there are still many questions to address related to this research. However, their work demonstrates that certain brine-calcite interactions, under applied stress, induce dissolution and decrease the frictional strength at the single-asperity scale.

“Our research also suggests that it might be possible to mitigate earthquake risk by purposely changing brine compositions in areas that contain calcite-rich rocks. This consideration could be beneficial in areas where fracking is taking place, but this concept requires much more careful investigation,” Espinosa-Marzal said.

“As a young scientist who works at the nanoscale, I never thought that earthquake dynamics would be the type of thing I would be researching,” Diao said. “However, we have learned so much about things at the macroscale that nanoscale studies like ours can reveal new critical insights into many large-scale natural phenomena.”

Site of Next Major Earthquake on San Andreas Fault

Many researchers hypothesize that the southern tip of the 1300-km-long San Andreas fault zone (SAFZ) could be the nucleation site of the next major earthquake on the fault, yet geoscientists cannot evaluate this hazard until the location and geometry of the fault zone is documented.

In their new paper published in the scientific journal GSA Lithosphere, Susanne Jänecke and colleagues use detailed geologic and structural mapping of the southern 30 km of the San Andreas fault zone in southern California to show that it is a highly faulted volume of rock that is 1-4 km wide and organized as a sheared ladder-like structure in the upper 3-5 kilometers of the earth.

This newly identified Durmid ladder structure is at least 25 km long, has tens of master right-lateral and right-reverse faults along its edges and hundreds of left- and right-lateral cross faults in between. The Durmid ladder structure trends northwest, extends from the well-known main trace of the San Andreas fault (mSAF) on the northeast side to a newly identified East Shoreline fault zone (ESF) on the opposite edge.

Many years of detailed field study validated the team’s 2011 hypothesis about the existence of the East Shoreline strand of the SAFZ northeast of the margin of the Salton Sea, and this paper documents this previously unknown active fault using geophysical and geologic datasets along the entire northeast margin of Coachella Valley, California. The East Shoreline fault, say the authors, probably becomes the Garnet Hills fault, north of Palm Springs, and together they parallel the mSAF for >100 km.

Uplifted, highly folded and faulted Pliocene to Holocene sedimentary rocks, evidence for pervasive shortening, map-scale damage zones, and extremely rapid block rotation indicate that convergence across the Durmid ladder structure of the SAFZ is the smaller, secondary component that accompanies more rapid right-lateral motions. Small amounts of shallow creep and triggered slip regularly produce hairline fractures along the mSAF and Jänecke and colleagues recognize identical features within the ESF and along some cross faults of the Durmid ladder structure.

It is not clear how past earthquakes interacted with this well-organized multi-fault structure, and, notes Jänecke, this makes future behavior difficult to predict. The mSAF was the only active fault considered by the geoscience community in this crucial area prior to our detailed study.

New and published geophysical data sets and drill hole data in Coachella Valley show that the East Shoreline fault is a voluminous fault zone that extends in all three dimensions. It is well-imaged southwest of the mSAF and appears to persist into the subsurface at the southwest edge of a flower structure that may converge and simplify at depth.

In such an interpretation, the ESF is steep, dips northeast, and is a key structure at the basinward edge of an asymmetric flower-like structure identified by Fuis et al. (2017) directly northwest of this study area. Southward, the Durmid ladder structure widens gradually as it bends and interacts with the even wider Brawley Seismic zone. The component of shortening across the southernmost San Andreas fault zone gives way along strike to components of extension in the Brawley Seismic Zone within a defined transition zone. This geometry makes it likely that both fault zones could fail during a single earthquake, as suggested by prior research.

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At Least 4 Dead, 375 Injured As Powerful Quake Hits Western Japan

Four people are dead and 375 others injured after an estimated magnitude-6.1 earthquake struck a wide area of western Japan including Osaka, Kyoto, Hyogo and Shiga prefectures on June 18.

According to the Osaka Prefectural Government and prefectural police, Rina Miyake, a 9-year-old girl, was crushed under a falling wall outside Takatsuki Municipal Juei Elementary School. Minoru Yasui, 80, was also crushed under a collapsed wall in Osaka’s Higashiyodogawa Ward. They were pronounced dead at hospital. Motochika Goto, 85, also died in the Osaka Prefecture city of Ibaraki. A woman in her 80s was also confirmed dead after she was crushed by a chest of drawers in Takatsuki, Osaka. At least 259 people were injured in Osaka, Kyoto, Hyogo, Shiga and Mie prefectures.

Toshiyuki Matsumori, director of the Japan Meteorological Agency (JMA)’s Earthquake and Tsunami Observation Division, warned at a news conference on the morning of June 18 that up to lower 6 earthquakes could hit the area over the next week or so.

The temblor hit at around 7:58 a.m., measuring a lower 6 on Japan’s 7-point seismic intensity scale in Osaka’s Kita Ward and the Osaka Prefecture cities of Takatsuki, Hirakata, Ibaraki and Minoo, the JMA said. The quake caused major disruptions of train services across the Kansai region, affecting many commuters during rush hour.

A total of 20 fires broke out in the city of Osaka, the Osaka Prefecture cities of Takatsuki, Suita and Minoo, and the Hyogo Prefecture city of Amagasaki, the Fire and Disaster Management Agency said.

Tokaido Shinkansen bullet train services were suspended between JR Maibara and Shin-Osaka stations, and Sanyo Shinkansen Line services were stopped between Shin-Osaka and Okayama stations. Tokaido Shinkansen operations were resumed at 12:50 p.m., but trains are traveling at reduced speeds in the affected section. Services on the Sanyo Shinkansen Line were restarted by 2:58 p.m.

Many local train services in Osaka, Kyoto, Nara and Hyogo prefectures have been halted due to the quake.

Runways at Kansai International Airport were closed at 8 a.m. but were reopened after no problems were found. No serious damage to its terminal building has been confirmed. An air conditioner suspended from the ceiling on the second floor of Osaka International Airport’s north terminal fell down after the quake, but nobody was injured.

Nuclear reactors in Oi, Mihama and Takahama in Fukui Prefecture are operating normally, according to their operators. According to Kansai Electric Power Co., a total of 170,000 households were without power at one point.

The earthquake, with a focus about 13 kilometers underground in northern Osaka Prefecture, registered a lower 6 on the Japanese intensity scale in northern Osaka Prefecture, the meteorological agency said. The areas that felt that intensity include Osaka’s Kita Ward and the cities of Takatsuki, Hirakata, Ibaraki and Minoo, also in Osaka Prefecture, according to public broadcaster NHK.

The JMA said that the earthquake’s intensity in the southern area of Kyoto Prefecture hit an upper 5 on the same scale, while parts of Shiga, Hyogo and Nara prefectures experienced a lower 5.

The quake did not cause tsunami, the agency said

‘Slow Earthquakes’ on San Andreas Fault Increase Risk of Large Quake

Geologists have long thought that the central section of California’s famed San Andreas Fault – from San Juan Bautista southward to Parkfield, a distance of about 80 miles – has a steady creeping movement that provides a safe release of energy.

This crackling on the central San Andreas during the past several decades, appears to reduce the chance of a big quake that ruptures the entire fault from north to south.

However new research by two Arizona State University geophysicists shows that the Earth movements along this central section have not been smooth and steady, as previously thought.

Instead, the activity has been a sequence of small stick-and-slip movements – sometimes called “slow earthquakes” – that release energy over a period of months. Although these slow earthquakes pass unnoticed by people, the researchers say they can trigger large destructive quakes in their surroundings. One such quake was the magnitude 6 event that shook Parkfield in 2004.

“What looked like steady, continuous creep was actually made of episodes of acceleration and deceleration along the fault,” says Mostafa Khoshmanesh, a graduate research assistant in ASU’s School of Earth and Space Exploration (SESE). He is the lead author of a Nature Geoscience paper reporting on the research.

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JUST IN: Iceland’s Largest Volcano Hit with Larger Quakes in Swarm

An earthquake swarm is currently engulfing Bardarbunga with two of its largest quakes measuring 4.1 and 4.9 magnitude. The latter earthquake is the largest since 2015 when Bardarbunga finished erupting after almost a year.

However, Iceland’s Met Office said there is no cause for concern at the time being. Bryndís Ýr Gísladóttir, natural hazard expert at the Iceland Met Office, said, “There are no signs of any volcanic unrest as yet.”

If the huge volcano were to blow, it could cause travel chaos across Europe and the Atlantic – much like its compatriot the Eyjafjallajökull volcano did in 2010. The Bardarbunga volcano is 6590 feet tall and lies hidden beneath the Vatnajökull glacier. This makes it increasingly difficult to monitor beyond a few acoustic measurements.

Geophysicists currently studying the volcano believe recent activity is the result of the volcano filling its magma chamber in preparation ahead of an eruption. The 2010 Eyjafjallajökull volcano eruption left 10 million air passengers stranded after grounding flights all around the world and cost the European economy around £4billion. Experts have stated if the Bardarbunga volcano was to come to life it would cause problems on a similar scale.

Earthquakes can suggest an imminent volcano explosion, as the magma moves through the cracks of the magma chambers. This causes pressure on the surrounding rock which causes the earthquakes, which are then tracked.

 

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As with all community services, it is time to request support with our services. We are hopeful to keep our research and news services available to all who seek this knowledge.

Needless to say we are convinced what we provide on Science Of Cycles informs its readers to be best informed of what is occurring right now in the present, but as importantly, what is most likely to occur in the near future.

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