Editor’s Note (4/8/21): On March 31, 2021, Russia submitted documents to an international commission claiming that far more of the vast Arctic Ocean seafloor belongs to that country. In recent years the five nations bordering the ocean—Russia, the U.S., Canada, Norway and Denmark (via its territory of Greenland)—have submitted claims that certain large portions of the Arctic seafloor are natural extensions of their continental shelf, giving them rights over those regions. But Russia’s new claim would take an additional 200,000 square kilometers from Denmark and even more from Canada. The original claims, and the science behind them, are detailed in our 2019 article below. More on the new Russian submission can be found in Arctic Today.