This could be a revolutionary—not just revolutionary, but life-saving—breakthrough! A team of French scientists has accidentally discovered that using a technology we’re already very familiar with—GPS—might make it possible to accurately predict earthquakes up to two hours in advance. Just think how many lives this could save! Earthquakes and Their Prediction Earthquakes are a common natural disaster, inflicting enormous losses and threats on humanity. According to statistics from the U.S. Geological Survey (USGS), approximately 1,500 earthquakes of magnitude 5.0 or higher occur worldwide each year, with about 15 of these reaching magnitude 7.0 or above, resulting in tens of thousands of deaths and displacing millions. As recently as February of this year, a sudden magnitude 7.8 earthquake struck parts of Turkey and Syria, killing nearly 60,000 people and leaving 1.5 million homeless. The quake also triggered tens of thousands of aftershocks, some nearly as strong as the main earthquake, further exacerbating the disaster’s destruction. How wonderful it would be if we could predict earthquakes in advance! This would give people enough time to find safe shelters, avoiding the risk of death and injury. Unfortunately, however, there is currently no effective method to predict earthquakes beforehand. At best, warnings can be issued seconds to tens of seconds after an earthquake begins. These warnings rely on monitoring the different propagation speeds of seismic waves through the Earth’s interior, using the time difference to send alerts to potentially affected areas. While they help to some extent, they are far from sufficient to prevent major disasters. But what if we could predict an earthquake roughly two hours in advance? This might sound like a plot from a science fiction novel, but a team led by Quentin Bletery and Jean-Mathieu Nocquet from the University of Côte d’Azur in Nice, France, may have found a way. What’s more, this method requires no new technology to be developed—only an existing technology we already know well: GPS. How Can GPS Predict Earthquakes in Advance? According to the media outlet SciTech Daily, French scientists recently identified a potential precursor signal that appears approximately two hours before a major earthquake. In their detailed study published in *Science*, they explained how they analyzed this signal using data from the Global Positioning System (GPS). The researchers believe that deploying monitoring networks near major fault lines could help realize the dream of earthquake prediction. Short-term earthquake prediction—issuing warnings minutes to months before an earthquake—depends on the existence of a clear, observable geophysical precursor signal. Previous retrospective studies have suggested that slow, non-seismic slips on fault lines may occur before a main earthquake, serving as a potential precursor. However, the link between these observations and actual seismic rupture remains unclear. This uncertainty arises because such observations do not directly precede events and often occur without subsequent earthquakes, leaving the existence of precise precursor signals for predicting major quakes in doubt. Reportedly, in this study, French scientists Quentin Bletery and Jean-Mathieu Nocquet conducted a comprehensive analysis of high-frequency GPS time series data preceding nearly 100 earthquakes of magnitude 7.0 or higher worldwide. They identified a pattern: approximately two hours before an earthquake, a subtle but accelerating displacement occurs on the fault line, causing horizontal movement of the land above. They also found that this displacement can be observed and measured using GPS, though it is too small to register on standard seismometers. Most importantly, they observed this same displacement in all the earthquakes they studied. According to the study’s scientists, these findings suggest that many major earthquakes begin with a precursor slip phase, or that these observations represent the final part of a longer, harder-to-measure precursor slip process. Their approach utilizes Global Navigation Satellite Systems (GNSS), such as the U.S. GPS, Europe’s Galileo, Russia’s GLONASS, or China’s BeiDou satellite network. The Earth is covered with ground-based receiving stations, some equipped with sensors of interest to geologists—including GNSS modules, which determine their location via triangulation with satellites from GPS, Galileo, GLONASS, or BeiDou. They used high-frequency GPS time series data from 3,026 global ground stations to assess fault displacement in the two hours before 90 different earthquakes of magnitude 7.0 or higher. Statistical analysis of this data revealed a subtle signal, consistent with a period of exponentially accelerating fault slip near the earthquake’s epicenter, beginning approximately two hours before rupture. Despite identifying a potential precursor signal before major quakes, Bletery and Nocquet caution that current earthquake monitoring instruments lack the necessary coverage and precision to detect or monitor precursor slips on the scale of individual earthquakes. In response, Roland Bürgmann, a professor at the University of California, Berkeley, wrote: “If it can be confirmed that earthquake preparation typically involves a precursor phase lasting several hours, and if methods to reliably measure it can be developed, then an early warning could be issued.” A Brief History of Earthquake Prediction Technology Early Seismic Exploration Technologies In the early stages of seismic exploration technology, people relied on simple methods and limited tools to gather information about subsurface structures. Below is a detailed overview of the development of these early technologies. Early seismic exploration techniques involved manually recording seismic wave data and using time-difference methods to locate epicenters. Epicenter location—the process of determining where seismic waves originate—is crucial for understanding subsurface structures. Early epicenter location methods depended on manual observations, comparing the arrival times of seismic waves to calculate the epicenter. However, this approach had low accuracy, limited by human factors and measurement errors. Measuring the propagation speed of seismic waves was another important early seismic exploration technique. By placing receivers on the Earth’s surface to record the arrival times of seismic waves, and combining these with epicenter location results, scientists could calculate the speed of seismic waves through different media. This technology provided insights into the properties of subsurface rocks and fluids, as well as the sequence and structure of geological layers. Seismic reflection, developed in the early 20th century, involved placing sources and receivers on the surface and recording how seismic waves reflect off subsurface layers to gather information about underground structures. The emergence of seismic reflection marked the entry of seismic exploration into an era of quantitatively describing subsurface structures. Early seismic reflection relied on manual analysis of seismic records, inferring underground structures by observing and interpreting waveforms. However, early seismic exploration had limitations and challenges. First, manual observation and data processing required significant human and material resources, were time-consuming, and prone to errors. Second, due to technological and equipment constraints, early exploration could only gather limited information about subsurface structures, failing to meet the needs of geological exploration and resource development. Despite these shortcomings, early seismic exploration laid the groundwork for later advancements. Its practices and lessons provided important foundations for subsequent technological improvements and innovations. Driven by advances in computer technology and data processing methods, seismic exploration broke free from traditional limitations, enabling more accurate and comprehensive descriptions of subsurface structures. In summary, early seismic exploration was the starting point for the field. Through manual recording of seismic wave data, epicenter location, and measurement of seismic wave propagation speeds, it initially revealed the characteristics of subsurface structures. While limited, early seismic exploration provided the basis for later technological innovation, laying a crucial foundation for the birth of modern seismic exploration. Modern Seismic Exploration Technologies Modern seismic exploration has advanced significantly, driven by progress in computer science, geophysics, and engineering technology. Below is a detailed look at its key features and applications. Rapid developments in computer technology have enabled a major leap from 2D to 3D seismic exploration. Traditional 2D seismic methods could only provide information about local subsurface structures, but 3D seismic technology uses dense sensor placement, records large volumes of seismic wave data via numerous receivers, and leverages high-performance computers for data processing and imaging to generate more accurate and comprehensive subsurface information. 3D seismic exploration is widely used in oil exploration, groundwater resource development, and engineering surveys. Pre-stack depth migration is a key method in modern seismic exploration. By accounting for the impact of subsurface inhomogeneity on seismic wave propagation, it processes and images seismic records to produce more accurate subsurface structure data. This technology eliminates artifacts caused by velocity model errors and medium inhomogeneity, improving imaging resolution and precision. It is invaluable in oil and gas exploration and geological hazard prediction. Downhole seismic technology involves installing seismic exploration instruments in drill holes to collect data and generate images. Combined with surface seismic data, it provides higher-resolution and more precise subsurface information. Downhole seismic technology is critical in oil and gas exploration and groundwater development. It offers detailed insights into subsurface structures around wells, aiding decision-making in oil and gas exploration and drilling operations, as well as supporting the rational development and management of groundwater resources. Advancements in modern seismic exploration have led to significant applications and breakthroughs. First, 3D seismic technology provides more accurate and comprehensive subsurface data, enhancing exploration efficiency and interpretive capabilities. Second, pre-stack depth migration eliminates artifacts in traditional seismic exploration, improving imaging quality and accuracy. Additionally, downhole seismic technology enables more comprehensive and detailed exploration data. However, modern seismic exploration still faces challenges. For example, data processing and interpretation in complex geological environments remain complex. Moreover, the equipment and human resources required for seismic exploration are costly, limiting its use in some regions and fields. In summary, modern seismic exploration has achieved major breakthroughs through 3D imaging, pre-stack depth migration, and downhole technologies. These techniques enable more accurate and comprehensive subsurface structure analysis, supporting oil exploration, groundwater development, and engineering surveys. As technology advances, modern seismic exploration will further improve resolution and interpretive capabilities, bringing more opportunities and challenges to subsurface resource exploration and geological hazard early warning. Sources: VC Venture Capital, Fengming Shuo Shi, Xu Dewen Science Channel