Saigon officials are investigating the cause of a shaking phenomenon which occurred last month in the downtown area.
According to Thanh Nien, teachers at District 1’s Nguyen Binh Khiem Primary School reported a shaking phenomenon in late February, in which the building would shake for several minutes a few times a day. The school’s principal, Lam Hong Lam Thuy, told the news outlet the shaking has since stopped, however the experience worried teachers.
In an effort to understand the phenomenon, the District 1 People’s Committee and the Department of Natural Resources and Environment are conducting an investigation on the matter, reports Thanh Nien. While city officials have ruled out seismic activity as a cause, experts are now exploring the possibility that large construction sites and low soil density are causing buildings in the surrounding area to shake.
According to the news outlet, similar incidents have been recorded in Binh Thanh District as well as areas south of downtown such as District 7, Nha Be and Binh Chanh. Given that many buildings in the city have relatively shallow foundations, structures may shake when large-scale construction projects take place nearby.
While local authorities have yet to present their official findings on the matter, a 2015 report by French and Vietnamese researchers noted that areas along the Saigon River and in the southern reaches of the city were especially susceptible to subsidence, or sinking. Between 2006 and 2010, the city sunk as much as 12 centimeters in some places due to excessive groundwater extraction, says the report, which was published in Remote Sensing, an open-access journal run by the Multi-Disciplinary Digital Publishing Institute.
According to the report, Saigon will become more susceptible to flooding as the city sinks, with deluges increasing both in area and frequency over time.