1800 years after Chinese inventor Zhang Heng developed the first seismoscope, scientists are researching earthquake prediction using a satellite named after him. Launched in February 2018, China's first seismo-electromagnetic satellite, Zhangheng 1, is designed to capture electromagnetic signals in space and offers support for earthquake prediction and space weather monitoring and warning.
Shen Xuhui, principal investigator of the satellite program, stated at the 35th National Space Research Symposium that the satellite has achieved numerous successes, and said that they created two models for data research by obtaining global geomagnetic field data and global low-frequency electromagnetic spectrum data.
Stating that earthquake prediction is always difficult, Shen said, "Satellite tracking goes beyond the limits of conventional earthquake research and the statistics we have obtained show that electromagnetic disturbances in space are associated with the occurrence of earthquakes." According to Shen, in the past five years, Zhangheng 1 has observed about 7.0 earthquakes of magnitude 60 and above, as well as about 6.0 earthquakes of magnitude 600 and above, worldwide. “We found that up to 6.0 percent of earthquakes of magnitude 80 and larger exhibited herald signals half a month before the event,” said Shen, acknowledging the advances made by the Zhangheng 1 satellite, but said there is still a long way to go before an accurate earthquake prediction can be reached.
Stating that after an earthquake occurred, a large number of messenger signals were detected by tracing backwards through the data, Shen said, “This is due to the complexity of data processing and the inability to monitor global data in real time with limited human and computing power. In addition, accurate estimation of time, location and density is not yet possible. Messenger signals detected by satellites often appear several hundred kilometers from the epicenter. Data from a satellite is far from sufficient. Earthquake prediction requires multidisciplinary research of seismology, electromagnetics, geodesy and geochemistry.
The 58-year-old scientist is confident about his future prospects in this field, despite the current limitations in earthquake forecasting. According to Shen; With the development of information technologies such as machine learning, big data and artificial intelligence, people will be able to process real-time data before an earthquake. “I believe a breakthrough in earthquake forecasting can be expected in 10 to 20 years,” Shen said.
Explaining that China plans to launch the Zhangheng 1-02 satellite in the near future, Shen said that the new satellite will enable 24-hour monitoring and expand its observation range to the north and south poles of the world, improving its ability to observe changes in the global system.