NASA finds attainable second giant impression crater underneath Greenland ice – Xinhua | English.information.cn – Xinhua
WASHINGTON, Feb. 11 (Xinhua) — Scientists realized final 12 months that the thick ice in Greenland lined up the trauma of Earth. Now, they discovered further proof.
The examine revealed Monday within the journal Geophysical Analysis Letters described a attainable second impression crater buried underneath greater than a mile (about 1.6 km) of ice in northwestern Greenland.
It comes after the invention of a 30-km-wide crater beneath Hiawatha Glacier in Greenland, the primary meteorite impression crater ever found underneath Earth’s ice sheets.
“The one different round construction which may strategy this measurement could be a collapsed volcanic caldera,” stated Joe MacGregor, a glaciologist with NASA.
“However the areas of identified volcanic exercise in Greenland are a number of hundred miles away. Additionally, a volcano ought to have a transparent constructive magnetic anomaly, and we do not see that in any respect,” stated MacGregor.
Solely about 183 km aside from the primary one, the newly discovered website, with a width of about 36 km, might have been shaped at a special time, in keeping with scientists at NASA.
The scientists discovered that the ice layers above the second crater have been older than these above Hiawatha, and the second crater is about twice as eroded.
Whether it is finally confirmed as the results of a meteorite impression, it is going to be the 22nd largest impression crater discovered on Earth, in keeping with the examine.
MacGregor’s workforce analyzed the uncooked radar photos to map the topography of the bedrock beneath the ice, together with these collected by NASA’s Operation IceBridge, an airborne survey of Earth’s polar ice.
Information from Operation IceBridge additionally revealed a unfavourable gravity anomaly over the realm, which is attribute of impression craters.