Though most of the thick ice remains, the thing that surprised the scientists is the area over which the melting is occurring. According to NASA, the melting area that is normally at 40% and has never crossed 55% in the past 30 years has shot up to 97%.

Son Nghiem of NASA’s Jet Propulsion Lab said, “This was so extraordinary that at first I questioned the result: Was this real or was it due to a data error?”

Ice core samples taken from Greenland’s highest region do reveal melting of such a proportion every 150 years. Last records points back to 1889 when such a large scale thaw was observed in Greenland. The frequency of 150 years might not just stay at that and may become more frequent due to warming sea and air temperatures.

Scientists haven’t been able to determine the cause of melting yet; whether it is because of global warming or it’s just another natural phenomenon.

Tom Wagner, NASA’s cryosphere program manager said, “This event, combined with other natural but uncommon phenomena, such as the large calving event last week on Petermann Glacier, are part of a complex story.”