Tag Archives: earthquake

Using Lasers, Fiber Optics, and Subtle Vibrations to Develop Earthquake Warning Systems

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When the Mendocino earthquake erupted off the California coast in 2024, it shook structures from their very foundations, triggered a 3-inch tsunami, and sparked intriguing scientific investigations in the server room of a nearby police station.

More than two years prior to the quake, scientists had installed a device known as the “Dispersed Acoustic Sensing Interrogation Room” at the Alcata Police Station located near the coast. This device utilizes a laser directed through a fiber optic cable that provides internet connectivity to the station, detecting how the laser light bends as it returns.

Recently, researchers revealed in a study published in the Journal Science that data collected from fiber optic cables can effectively be used to “image” the Mendocino earthquake.

This research demonstrates how scientists can convert telecommunication cables into seismometers, providing detailed earthquake data at the speed of light. Experts noted that this rapidly advancing technology has the potential to enhance early earthquake warning systems, extending the time available for individuals to take safety measures, and could be critical for predicting major earthquakes in the future.

James Atterholt, a research geophysicist for the US Geological Survey and lead author of the study, stated, “This is the first study to image the seismic rupture process from such a significant earthquake. It suggests that early earthquake warning alerts could be improved using telecom fibers.”

The study proposes equipping seismometers with devices capable of gathering sparse data from the extensive network of telecommunications cables utilized by companies such as Google, Amazon, and AT&T, making monitoring submarine earthquakes—often costly—more affordable.

Emily Brozky, a professor of geoscience at the University of California, Santa Cruz, asserted that “early earthquake warnings could be dramatically improved tomorrow” if scientists can establish widespread access to existing communication networks.

“There are no technical barriers to overcome, and that’s precisely what Atterholt’s research emphasizes,” Brozky mentioned in an interview.

In the long term, leveraging this technology through fiber optic cables could enable researchers to explore the possibility of forecasting some of the most devastating earthquakes in advance.

Scientists have observed intriguing patterns in underwater subduction zones prior to significant earthquakes, including Chile’s magnitude 8.1 quake in 2014 and the 2011 Tohoku earthquake and tsunami in Japan.

Both of these major earthquakes were preceded by what are known as “slow slip” events that gradually release energy over weeks or months without causing noticeable shaking.

The scientific community is still uncertain about what this pattern signifies, as high-magnitude earthquakes (8.0 or greater) are rare and seldom monitored in detail.

Effective monitoring of seismic activity using telecommunications networks could enable scientists to accurately document these events and assess whether discernible patterns exist that could help predict future disasters.

Brodsky remarked, “What we want to determine is whether the fault will slip slowly before it gives way entirely. We keep observing these signals from afar, but what we need is an up-close and personal instrument to navigate the obstacles.”

While Brodsky emphasized that it’s still unclear whether earthquakes in these extensive subduction zones can be predicted, she noted that the topic is a major source of scientific discussion, with the new fiber optic technology potentially aiding in resolving this issue.

For nearly 10 years, researchers have been investigating earthquake monitoring through optical fiber cables. Brodsky stated that the study highlights the need for collaboration among the federal government, scientific community, and telecommunications providers to negotiate access.

“There are valid concerns; they worry about people installing instruments on their highly valuable assets and about the security of cables and privacy,” Brozky explained regarding telecom companies. “However, it is evident that acquiring this data also serves the public’s safety interests, which makes it a regulatory issue that needs to be addressed.”

Atterholt clarified that fiber optic sensing technology is not intended to replace traditional seismometers, but rather to complement existing data and is more cost-effective than placing seismometers on the seabed. Generally, using cables for earthquake monitoring does not interfere with their primary function of data transmission.

Jiaxuan Li, an assistant professor of geophysics and seismology at the University of Houston, noted he was not involved in the study but mentioned that there are still technical challenges to the implementation of distributed acoustic sensing (DAS) technology, which currently functions over distances of approximately 90 miles.

Li also pointed out that similar methods are being employed in Iceland to monitor magma movements in volcanoes.

“We utilized DAS to facilitate early warnings for volcanic eruptions,” Li explained. “The Icelandic Meteorological Office is now using this technology for issuing early alerts.”

Additionally, the technique indicated that the Mendocino tremors were rare “supershear” earthquakes, which occur when fault fractures advance quicker than seismic waves can travel. Atterholt likened it to a fighter jet exceeding the speed of sound.

New research has serendipitously uncovered patterns associated with Mendocino, providing fresh insights into this phenomenon.

“We still have not fully grasped why some earthquakes become supershear while others do not,” Atterholt reflected. “This could potentially alter the danger level of an earthquake, but the correlation remains unclear.”

Source: www.nbcnews.com

Kamchatka Earthquake Response Demonstrates Enhanced Tsunami Warning System

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The coastline of Shiogama, Japan, where a tsunami warning was issued following a significant earthquake

Asahi Shimbun via Getty Images

On July 29, a strong earthquake struck near Russia’s Kamchatka Peninsula, prompting a quick tsunami warning that allowed millions to evacuate safely. Although no unexpected waves materialized, the swift response demonstrates the progress made in tsunami science since the devastating tsunamis in 2004 and 2011, which cost tens of thousands of lives.

“This is an excellent accomplishment built on lessons learned from previous incidents,” said Ravindra Jayaratne, a researcher at the University of East London, UK.

The efficiency of the warning system can be attributed to an enhanced network of tsunami detection sensors. This includes seismometers that detect earthquake tremors and a series of buoys managed by the US National Oceanic and Atmospheric Administration, which assess wave heights and relay crucial information to satellites. Improved modeling techniques enable researchers at the Tsunami Warning Office to swiftly predict and disseminate alerts about wave impact locations and times.

On the day of the event, tsunami offices across the Pacific region were able to issue alerts almost immediately after the 8.8 magnitude earthquake was detected—recorded as the strongest ever. In Japan, approximately 2 million individuals evacuated from coastal regions, with others doing the same in Hawaii and even in Chile, located just south of the US west coast.

“The reaction was prompt and effective,” noted David Tappin from the British Geological Survey. He added, however, that despite the earthquake’s intensity, it resulted in minimal wave activity and flooding, highlighting the need for improved predictive capabilities regarding flood events based on early detection of tremors and wave conditions.

Jayaratne also pointed out that regions prone to tsunamis, such as Bangladesh and Sri Lanka, lack a robust warning system and adequate public awareness of potential risks. “History shows that advanced detection technologies are only useful when accompanied by effective public communication and comprehensive evacuation strategies,” he said. “Coastal communities must conduct drills regularly to enhance public awareness and ensure warnings reach those in need through various channels.”

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Source: www.newscientist.com

Tsunami Advisory Issued for Alaska Following 7.3 Magnitude Earthquake off the Aleutian Islands

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Alaska’s coastal regions were on alert for a tsunami Wednesday following a 7.3 magnitude earthquake that hit the Ariuya Islands, according to officials.

The earthquake occurred at 12:38 PM local time (4:38 PM ET), with its epicenter located 55 miles south of Sandpoint, a community on Popf Island. The quake was recorded at a depth of 12 miles.

Tsunami data was not immediately available, and effects for Kodiak Island were not anticipated until 2:40 PM local time (6:40 PM ET).

Although no large-scale flooding is expected, the Tsunami Warning Center stated that dangerous currents and waves could pose risks to those in close proximity.

The initial tsunami warning has since been adjusted to a tsunami advisory.

These advisories span various coastlines, from Unimak Pass in the Aleutians to the entrance of Kennedy, located 40 miles south of Homer.

Emergency personnel in Kodiak, a city of around 5,500 that lies about 250 miles south of Anchorage, announced that shelters would be opened and sirens sounded prior to the warning being downgraded.

“The sirens are sounding, and remain vigilant if you’re near the coast,” Kodiak Island Emergency Management advised on social media.

Emergency officials reported no threat to Anchorage, Alaska’s largest city, following the earthquake.

Debi Schmidt, the city manager of Sand Point, discussed the earthquake with NBC affiliate Ktuu, describing it as the strongest quake she had ever experienced.

“I was at home for lunch when the house began to shake; things were falling, and the cupboard door swung open,” she recounted to the station. “Fortunately, there was no damage.”

Source: www.nbcnews.com

Rescuers in Landslide Efforts to Utilize Swift Earthquake Data Analysis

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Community members investigating a landslide in Yangbari, Papua New Guinea, in 2024

Xinhua Newsletter/Aramie

In the event of a landslide, pinpointing the location can be crucial for rescue teams. Recent advancements in earthquake data analysis have made it possible to identify the source of such disasters within just a few kilometers in a matter of seconds.

Current methods can generally limit the area of interest to tens of kilometers, as noted by Stefania Ursica from the Helmholtz Geoscience Centre in Germany. This limitation can result in significant delays if rescuers are directed to an incorrect site. “The time lost is critical,” Ursica stated during a press briefing at the European Geoscience Union Conference in Vienna last week.

Numerous countries maintain seismic monitoring networks to track earthquakes and volcanic activity. This data can also aid in detecting landslides, especially as the risks associated with climate change intensify. However, analyzing data from landslides is considerably more complex than that from earthquakes, according to Ursica.

Her team’s innovative approach involves two key components. First, they assess five distinct facets of the seismic waveform and filter out noise when an event occurs.

This information is processed by numerous mathematical agents that seek the origin of the initial rock-like event that leads to a landslide. They accomplish this by estimating which waveforms would have been generated at various possible locations and comparing those estimations with the data captured. If the waveforms do not align, they will explore other options.

Each agent “travels” following patterns inspired by animal behavior, such as the spiral of falcons or the migration paths of elephants, until they converge back to the most plausible site of the event. This whole procedure takes approximately 10 seconds, providing far greater accuracy than previous methods. “It’s a few digits of improvement,” Ursica adds.

Aside from enhancing rescue operations, this new technique will assist researchers in locating events in remote regions where satellite data may be limited or unavailable.

The team plans to release their findings and make the underlying code accessible to the public.

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Source: www.newscientist.com

When to Alert the Public: Seismologists Investigate Forewarnings of Impending “Major Earthquake”

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New studies conducted by USGS geophysicist Danny Brothers reveal that the Cascadia subduction zone, stretching along the US west coast from northern California to northern Vancouver Island, may have seen around 30 large earthquakes over the past 14,200 years. On average, a large earthquake could occur in that area approximately every 450 to 500 years.

Despite this history, the Cascadia Volcano has remained dormant for years, as many scientists believe the volcano is mainly “frozen” and under immense pressure. Should the volcano erupt, it could cause a significant shift in the ocean floor, leading to potential tsunamis heading towards the shore.

Washington State Emergency Management Director Robert Ezell has warned that this event could be the most catastrophic natural disaster in the country’s history.

Seismologists are now focused on predicting these potential cataclysms, with research suggesting that faults like Cascadia and Nankai may give off warning signs, such as minor foreshocks or subtle tremors only detectable by specialized sensors (known as slow-slip events).

In a worst-case scenario proposed by Tobin, if the Cascadia Fault were to release such vibrations suddenly, the consequences could be devastating.

A major earthquake in the Cascade Range could leave over 100,000 people injured, lasting for five minutes and generating tsunamis along the coast for up to 10 hours. Liquefaction could occur in inland hills, destroying roads and bridges, with around 620,000 buildings, including hospitals and schools, facing severe damage or destruction.

Ezell emphasized that the state is not adequately prepared for such an event, warning residents to be self-sufficient for at least two weeks following a disaster.

The maps of the Pacific Ring of Fire, where tectonic plates converge to create subduction zones and volcanoes, particularly concern Ezell.

“Over the past few decades, we’ve witnessed major ruptures in all subduction zones’ faults except for Cascadia,” Ezell noted.

Source: www.nbcnews.com

Japan’s First “Major Earthquake Warning” and Its Significance

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summary

  • Japan’s Meteorological Agency issued its first-ever “major earthquake warning” on Thursday.
  • The warning came after a magnitude 7.1 earthquake struck off the coast of the southern part of the country.
  • This raises the risk of an even bigger earthquake in the Nankai Trough, an undersea subduction zone that scientists believe could produce a quake of up to magnitude 9.1.

After a magnitude 7.1 earthquake struck Japan’s southern islands on Thursday, the country’s Meteorological Agency issued an ominous warning: More powerful quakes are possible, with the risk especially high over the coming week.

The Japan Meteorological Agency issues its first-ever “major earthquake warning,” warning that the Nankai Trough is a subduction zone where a magnitude 8-9 earthquake is likely to occur, and that there is a higher-than-usual risk of strong shaking and tsunamis. It urges people in the area to prepare.

The message is not a prophecy but an outlook for increasing risk, and it shows how far seismologists have come in understanding the dynamics of subduction-zone earthquakes.

Here’s what you need to know about the situation.

Dangerous subduction zones

The Nankai Trough is an underwater subduction zone where the Eurasian plate collides with the Philippine Sea plate, causing the latter to subduct beneath the Eurasian plate and sink into the Earth’s mantle.

Faults in subduction zones build up stress, and when the locked faults slip and release that stress, so-called megaquakes occur. “Mechatronics” is the shortened form of the name. These zones have produced some of the most powerful earthquakes in Earth’s history.

The Pacific “Ring of Fire” is a collection of subduction zones. In the United States, the Cascadia Subduction Zone off the West Coast stretches from Vancouver Island in Canada to Cape Mendocino in California.

The Nankai Trough fault is divided into several segments, but if the entire edge of the fault slips at once, Japanese scientists say the trough will It could cause an earthquake of up to magnitude 9.1.

In the southwestern Japanese city of Nichinan, beaches were closed on Friday after the country’s first warning of a possible major earthquake was issued.
Kyodo News via Reuters Connect

If a major earthquake were to occur off the coast of Japan, the Philippine Sea Plate would likely shake 30 to 100 feet near the country’s southeast coast, causing violent shaking.

Vertical displacement of the ocean floor could trigger a tsunami, sending waves crashing onto the coast of Japan that Japanese scientists estimate could reach heights of nearly 100 feet. Published in 2020.

History of major earthquakes

Large earthquakes occur in the Nankai Trough approximately every 100 to 150 years. In last year’s surveyJapan’s Earthquake Research Committee announced in January 2022 that there is a 70 to 80 percent chance of a major earthquake occurring in the next 30 years.

Great Nankai Trough earthquakes tend to occur in two separate events, with the second often occurring within two years of the previous one, recent examples being the “twin” earthquakes that occurred in the Nankai Trough in 1944 and 1946.

This phenomenon is due to the segmented nature of the fault, where a shift in one segment can put strain on other segments.

Thursday A magnitude 7.1 earthquake occurred at or near a subduction zone.According to the U.S. Geological Survey.

People stand outside after escaping a building following an earthquake in Miyazaki on Thursday.
Kyodo News via Associated Press

Harold Tobin, a professor at the University of Washington who studies the Nankai Trough, said the magnitude 7.1 quake occurred in a segment that shakes more frequently than other earthquakes. The regular quakes reduce stress, so there’s less concern that the segment itself could cause a big one. What’s concerning is the quake’s proximity to a segment that’s been building up stress since the 1940s.

“This one is adjacent to the Southwest Sea region and is obviously sealed off, so that’s a reason for caution and concern,” Tobin said.

Predictions, not predictions

Scientists cannot predict earthquakes, but they are developing the ability to forecast when danger is heightened, especially in areas like Japan where tremors occur frequently and monitoring is well established.

Source: www.nbcnews.com

Taiwan’s Earthquake Preparedness Shines, Surpassing US Efforts

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Taiwan experienced a significant earthquake on Wednesday, with experts noting that it was larger than some areas in the United States. The island was well-prepared for seismic disasters, which helped mitigate the impact. Despite nine reported deaths, authorities anticipate the death toll may increase. Over 1,000 individuals were injured, and around 100 are feared trapped.

The earthquake, measuring 7.4 in magnitude, highlighted Taiwan’s robust early warning system, modern seismic building codes, and the population’s familiarity with seismic activity. Following the devastating Chichi earthquake in 1999, Taiwan made substantial upgrades to its infrastructure to enhance resilience.

Geologist Larry Shuhen Lai, who grew up and studied in Taiwan, acknowledged the progress made in earthquake preparedness, comparing the nine deaths in the recent earthquake to the 2,400 casualties in the past. He emphasized Taiwan’s serious approach to earthquakes as part of daily life.

Experts noted that U.S. cities on the West Coast are taking various measures to prepare for earthquakes, but none are as well-prepared as Taipei, the capital of Taiwan.

A California Highway Patrol trooper checks for damage to a fallen car when the upper section of the Bay Bridge collapsed into the lower section after the Loma Prieta earthquake in San Francisco on October 17, 1989.George Nikitin/AP File

Taiwan is still assessing the earthquake’s impact and lessons learned, providing valuable insights for U.S. scientists and leaders to evaluate their own infrastructure and preparedness.

John Wallace, a civil engineering professor, highlighted the damage to older concrete buildings in Taiwan and emphasized the importance of retrofitting such structures. Taiwan’s skyscrapers, like Taipei 101, showcased advanced engineering that performed well during the earthquake.

Overall, experts commended Taiwan’s earthquake preparedness efforts, attributing them to the previous Chi-Chi earthquake that spurred significant improvements in safety measures and building codes.

Damaged buildings in Hualien City, Taiwan, on Tuesday.TVBS via AP

Taiwan’s gradual progress in earthquake safety, coupled with public education and trust in authorities, has been integral to its preparedness. Initiatives undertaken post the Chi-Chi earthquake have set the benchmark for earthquake resilience in the region.

The comparison with U.S. readiness, particularly on the West Coast, reveals disparities in earthquake preparedness, with Taiwan’s advanced early warning system being a standout feature. The system’s effectiveness in disseminating warnings and promoting public safety serves as a model for other earthquake-prone regions.

Both Taiwan and the U.S. utilize advanced warning systems based on seismic wave detection, highlighting the importance of continuous improvement and proactive measures to enhance earthquake resilience.

In conclusion, Taiwan’s 25-year journey towards earthquake preparedness offers valuable insights for other regions, emphasizing the significance of strategic planning, infrastructure upgrades, and community engagement in mitigating the impact of seismic events.

Source: www.nbcnews.com