People walk on ice in frozen sea waters off Dalian in Liaoning province on Saturday. (Lyu Wenzheng/For China Daily)
The North China Sea Marine Forecasting Center of the State Oceanic Administration has issued blue alerts for sea ice in Liaodong Bay three times since Friday, warning of potential threats to offshore oil drilling, waterway safety and fishery industries.
The latest satellite images showed ice in the bay reached 17,088 square kilometers on Sunday, accounting for 56 percent of the bay's total area, with ice in some parts up to 40 centimeters thick.
Located in the Bohai Sea, Liaodong Bay has some of China's lowest coastal seawater temperatures and the heaviest sea ice coverage.
The center predicted the growth of ice in the bay will slow over the next three days with warming temperatures.
With interior portions of China experiencing heavy snowfalls, the past week saw the coldest temperature in Hulunbuir League, Inner Mongolia autonomous region, with an extreme low of -50 C on Jan 25.
Yuan Benkun, a researcher at the center, said: "The continued cold temperature is responsible for the sea ice expanding. This means the melting process will take more time."
The 13.5-sq-km Juehua Island is the largest island in Liaodong Bay, and is home to 3,000 residents.
Waterborne traffic to Juehua Island typically does not begin until late March, according to Zhang Guihui from the local marine traffic office.
A local marine forecasting and disaster center urged relevant departments to strengthen ice-breaking efforts and provide basic necessities to island residents while ensuring the safety of shipping and marine operations.
The sea ice alerts are classified into four levels: red, orange, yellow and blue. The blue alert in Liaodong Bay means ice thickness is reaching 30 cm and the sea ice's outer margin has expanded to 130 km from shore.