Research using daily GPS data has improved our understanding of the early post-earthquake period, provided more accurate estimates of seismic hazard, and improved emergency response and preparedness strategies.

Revolutionary research has revealed new information about the behavior of the Earth’s crust immediately after earthquakes. Researchers used daily Global Positioning System (GPS) solutions to precisely measure the spatial and temporal evolution of the early aftershock of the 2010 8.8 Mole earthquake. This innovative approach represents a significant advance in seismic analysis by providing a more accurate and rapid representation of ground deformations, which is essential for assessing seismic hazard and understanding fault line activity.

The aftermath of an earthquake is characterized by complex post-seismic reconstructions, especially an elusive early aftershock. Daily seismic monitoring attempts to record the rapid and complex ground motions that occur during the critical hours following the earthquake. The complexity of these initial measures and their profound implications for seismic hazard assessment underscore the urgent need for more sophisticated and operational monitoring methods.

Innovations in seismic data analysis

In a paper published in the journal Satellite Navigation on July 29, 2024, researchers from Wuhan University presented their detailed study of the early period after the Maule earthquake. Using daily GPS solutions, the study provides a comprehensive description of the deformations that occurred on the Earth’s surface in the first hours after the earthquake.

This study uses daily GPS data to generate a high-resolution image of the aftershock of the 2010 8.8 Moley earthquake. The innovative approach reduces the overestimation of seismic displacements by approximately 10% by capturing rapid ground deformations that are usually missed in daily GPS measurements. The study reveals the dominance of aftershocks in the first 36 hours, overshadowing porous-elastic effects, and makes a significant contribution to seismic hazard assessment. The results increase the clarity and depth of our understanding of the Earth’s post-seismic dynamics, providing a reliable tool for improving early warning systems and disaster response strategies.

“Our study demonstrates the ability of daily GPS to capture the complex dynamics of the early aftershock, which is critical for seismic risk assessment and deciphering post-earthquake fault behavior,” said Dr. Yanmao Wen, author of the study.

The daily use of GPS in seismic surveys heralds a new era in hazard management. This will allow for more accurate and faster assessment of post-earthquake activity, enabling more effective response to earthquake consequences. Increasing the accuracy of measurements in the early stages of seismic activity will improve the prediction of aftershocks, optimize emergency preparedness, and reduce the seismic vulnerability of at-risk communities. This advancement in geodetic monitoring is a step toward a deeper understanding of earthquake dynamics and their societal consequences.