|Karst cave, also known to be a subsurface cavern, has been blamed for a 30m-wide sinkhole that suddenly formed in central Thanh Hoa Province last Tuesday. — Photo Vnexpress
HA NOI (VNS) — Karst cave, also known to be a subsurface cavern, has been blamed for a 30m-wide sinkhole that suddenly formed in central Thanh Hoa Province last Tuesday.
Do Canh Duong, deputy head of the General Deparment of Geology and Minerals of Viet Nam under the Ministry of Natural Resources and Environment, revealed the existence of the sinkhole at the ministry's monthly press conference last Friday.
At first, the sinkhole, located in Yen Dinh District's Quy Loc Commune, was only about 1.5 metres deep but later deepened further by more than 25 meters, said Duong, adding that the sinkhole's width continued to expand. No casualties have been reported so far.
Duong also revealed that he and other geological experts of the ministry had reviewed the district's geological situation last Thursday.
The general department also ordered its unit, the north central geology division, to conduct surveys to identify the scale of the subsurface cavern, Duong said.
"It takes about one week to complete a professional assessment of the situation," he explained.
The assessment is expected to help provincial authorities give solutions to residents living near the sinkhole, he added.
The ministry has ordered its department in the province to immediately conduct a temporary evacuation of residents living near the sinkhole.
At the press conference, Deputy Natural Resources and Environment Minister Tran Hong Ha said that, based on regulations, before residential areas were established, concerned agencies had to consider the geological database there.
Because numerous subsidence cases were recently reported, the ministry will re-check construction planning for areas with high risks of subsidence nationwide in the future, Ha added.
He revealed that the ministry was creating a map to identify areas that were geohazards or at high risk of subsidence throughout the country, to help affected localities formulate effective and responsive socio-economic development plans in the future. — VNS