VietNamNet Bridge – From the evening of September 22 to noon of September 23, up to six quakes occurred in the area of Song Tranh 2 hydro-power plant in Quang Nam province.

The seismic station in Hue city measured the most powerful earthquake of up to 4.8 Richter scales while the Institute of Geophysics confirmed it was 4.1 Richter scales.

While people in Bac Tra My district and in a number of neighboring areas of the Song Tranh 2 Hydropower Plant were having lunch, the earth emitted rumbling explosions, floor wobble lasted for more than 10 seconds.

"I was bringing the tray of food to the table when the earth emitted explosion. The house crunched. I was scared and dropped the tray. People stampeded. If it continues like this, I can die of quakes or of a heart attack," said Ms. Nguyen Thi Mai, a resident in Bac Tra My Town.
 
Mr. Tran Anh Tuan, Vice Chairman of Bac Tra My district, said he was deeply worried. The six consecutive earthquakes occurred from 9pm on September 22 to noon of September 23-- making people’s fear to the climax. The seismic station in Hue had notified local authorities that the strongest earthquake occurred at 10:57am on September 23 was up to 4.8 on the Richter scale, the largest ever.

"The biggest worry is the safety of the people. Increasingly strong earthquakes occur continuously while the geological foundation is week, so civil works and houses in the area cannot resist," said Tuan.

Mr. Tran Van Hai, Manager of the Hydroelectric Projects Management Unit 3 (which directly manages Song Tranh 2) also said that the accelerators measuring earthquakes installed at the Song Tranh 2 dam recorded the earthquake at noon of September 23 up to 4.8 on the Richter scale. Currently, the dam is still safe.

However, the Geophysics Institute confirmed that the strong earthquake occurred at 10:57am on Sunday was just 4.1 on the Richter scale.

Prof. Cao Dinh Trieu, from the Institute of Geophysics, analyzed that the Hydropower Projects Management Unit 3 announced that the vibration acceleration of the earthquake at noon of Sunday was 91 cm/s2. The shock target depth of this earthquake was 7 km, the epicenter which occurred in Tra Bui commune, Bac Tra My district, around 27.5 km from Song Tranh 2 dam.

"Therefore, the powerful earthquake this noon is certainly greater than the quake of 4.2 on the Richter scale which had occurred in the region before," he said.

Earlier, the two largest earthquakes recorded in the region happened at 20:46 on September 3 with a magnitude of 4.2 Richter scale and at 9h27 on September 7 with magnitude of 4 on the Richter scale.

M. Lan