Abashiri Local Meteorological Observatory announced "the sea open" of Abashiri-shi, Hokkaido and Monbetsu-shi on 3rd of March. The first day when I became it half of the quantity of sea ice in view became as follows as for "the sea open", and to be able to navigate a ship on the coast. It was observed in Monbetsu in Abashiri on 17th on February 15. I say the second speed since an observation start of 1956 early for approximately 1 month from an average year.

If it becomes almost spring as for the sea ice, it goes away from the shore and approaches and repeats it, but it is it with announcement of "the sea open" when judged unless I approach it anymore.