NASA and NSIDC scientists report that sea ice in the Arctic reached an annual minimum extent of 1.7 million square miles on September 11th, 2015. According to scientists, it is the fourth lowest extent on record. Scientists have continuously monitored Arctic sea ice using satellites since 1979. Compared to the 30-year average. 1981-2010, this year's minimum extent is 699,000 square miles lower a difference an area comparable to the state of Alaska. Scientists have observed a trend in declining sea ice coverage over the past three decades. Satellite measurements show 10 record minimums have occurred in the last 11 years. Measurements also show that more than the thin seasonal ice is melting. The thicker and slower growing multi-year ice is becoming increasingly less resilient. As a result, scientists say this year's ice-melt may be setting things up for an even larger melt in future years. music