# Seismic activity and warning system error in Yibin, Sichuan

> Live situation record from CLSTR: https://clstr.news/situations/seismic-activity-in-yibin-sichuan
> Updated: 2026-08-23T20:21:33.000Z. Sources: 6. Developments: 2.

Sichuan province has experienced a period of increased seismic activity, particularly within the Yibin region. On June 29, a 5.5 magnitude earthquake caused at least 15 injuries and damage to approximately 900 homes. Subsequent tremors included two earthquakes on August 3 measuring 4.8 and 4.2, and a 4.9 magnitude earthquake in Gao County on August 7.

On August 24, 2026, a 4.7 magnitude earthquake struck Changning County in Yibin. While no casualties were immediately reported, the event triggered widespread panic due to a major error in the earthquake early warning system. Initial alerts sent to mobile devices and smartwatches incorrectly predicted a magnitude of 7.7.

The Chengdu Hi-tech Disaster Reduction Institute apologized, describing the 7.7 magnitude report as the “largest discrepancy in the system’s 15-year history.” The institute attributed the error to the earthquake’s shallow 5-kilometer focal depth, which caused peak ground acceleration to reach 153mg, leading the automated system to overestimate the magnitude before correcting it.

Following the event, a dispute arose between the Sichuan Earthquake Bureau and the institute regarding the unauthorized use of the name ‘China Earthquake Early Warning Network’. The Bureau stated that third-party services had been terminated in July 2026, while the institute maintained that the name was established through a 2020 memorandum of understanding co-signed with the China Earthquake Administration.

## Claims

- A 4.9 magnitude earthquake struck Yibin in Sichuan province. (corroborated by 2 sources)
- The earthquake occurred in Changning County at 08:26 local time. (corroborated by 2 sources)
- The epicenter was located at 28.32 degrees north latitude and 105.01 degrees east longitude. (corroborated by 2 sources)
- No immediate information regarding casualties or damage has been released. (corroborated by 2 sources)
- Yibin has experienced several seismic movements in recent weeks. (corroborated by 2 sources)
- A 4.9 magnitude earthquake previously struck Gao County on August 7. (corroborated by 2 sources)
- Two earthquakes of magnitude 4.8 and 4.2 occurred in Gao County on August 3. (corroborated by 2 sources)
- A 5.5 magnitude earthquake on June 29 caused injuries to at least 15 people and damaged approximately 900 homes. (corroborated by 2 sources)

## Timeline

### 2026-08-23: Sichuan province earthquake hits Yibin city

A 4.9 magnitude earthquake struck Changning County in Yibin, Sichuan province, China. The region has experienced frequent seismic activity over the past two months.

6 sources. https://clstr.news/cluster/sichuan-province-earthquake-hits-yibin-city

### 2026-08-05: Magnitude 4.9 Earthquake Strikes High County, Yibin, Sichuan, China

A magnitude 4.9 quake hit High County, Yibin, Sichuan on 7 Aug 2026 (depth 6 km). No casualties or damage reported.

3 sources. https://clstr.news/cluster/magnitude-49-earthquake-strikes-high-county-yibin-sichuan-china

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Cite as: Seismic activity and warning system error in Yibin, Sichuan. CLSTR, https://clstr.news/situations/seismic-activity-in-yibin-sichuan