a number of causes for the massive loss of ice this summer: firstly, during the previous winter, primarily thin sea ice was formed in Russia’s marginal seas, and soon melted again when the spring came [...] Arctic Ocean
This summer the sea-ice cover on the Arctic Ocean shrank to the second-smallest extent since the beginning of satellite observation in 1979. By mid-September it covered only 3.8 million [...] the Arctic has seen extremely high air and water temperatures. Accordingly, heat gnawed away at the ice from both above and below, resulting in widespread melting.