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
