According to the Earthquake and Tsunami Warning Center under the Institute of Earth Sciences, the first earthquake, measuring 2.7 on the Richter scale, occurred at 10:41:33 a.m. in Tra Giap Commune. Its focal depth was approximately 8.1 kilometers, at 15.171 degrees north latitude and 108.230 degrees east longitude.
More than 10 minutes later, a second earthquake, measuring 2.6, struck Tra Tan Commune at 15.209 degrees North latitude and 108.166 degrees East longitude, at a depth of about 8.1 kilometers.
At 11:23:20 a.m., a third earthquake, measuring 3.0, occurred in Tra Tap Commune at 15.124 degrees North latitude and 108.111 degrees East longitude, with a focal depth of approximately 8.1 kilometers.
Mr. Ngo Tan Lac, Vice Chairman of the Tra Tap Commune People’s Committee, said he clearly felt the earthquake while working at his office, as the building shook. Many local residents also felt the tremors.
Mr. Bui Ngoc Luan, Principal of the Nam Tra My Ethnic Minority Boarding Secondary and High School, said residents in Tak Po, Nam Tra My Commune, located 7 to 25 kilometers from the earthquake epicenter, felt successive tremors and experienced shaking in their homes during the period.
“The strongest tremor occurred shortly after 11:20 a.m. I was working in the school’s two-story building at the time. The shaking was very strong,” Mr. Luan recalled.
The strongest shaking occurred around school dismissal time, when students were heading to the ground-floor dining hall for lunch. This was not the first time tremors had been recorded in the Nam Tra My area in recent days.
Previously, at 2:46:59 a.m. on September 13, a 2.5-magnitude earthquake struck Nam Tra My Commune at 15.179 degrees north latitude and 108.211 degrees east longitude, with a focal depth of approximately 8.2 kilometers.
Then, at 6:16:38 p.m. on September 14, another 2.5-magnitude earthquake occurred in Son Tay Commune, Quang Ngai Province, about 50 kilometers southwest of Nam Tra My. The earthquake was recorded at 14.962 degrees north latitude and 108.366 degrees east longitude, with a focal depth of approximately 8.1 kilometers.
Thus, within five days, from September 12 to 17, five earthquakes measuring between 2.5 and 3.0 were recorded in the mountainous Nam Tra My area and neighboring communes in Da Nang, as well as Son Tay Commune in Quang Ngai Province. Their focal depths ranged from 8.1 to 8.2 kilometers.
All of the earthquakes were assigned a natural-disaster risk level of 0, the lowest level on the warning scale.
