Text-on-screen video about a possible new impact crater under Greenland's ice
Just 114 miles from the newly-found Hiawatha impact crater under the ice of northwest Greenland, lies a possible second impact crater. The 22-mile wide feature would be the second crater found under an ice sheet, and if confirmed, would be the 22nd-largest crater on Earth. A NASA-led team discovered the feature using satellite data of the surface of the Greenland Ice Sheet as well as radar measurements from the airborne campaign Operation IceBridge. Although the two massive craters lie fairly close to each other, it’s thought they weren’t created at the same time. The second crater looks to be much older than Hiawatha, with features that are significantly more eroded, and it contains older ice than its neighbor.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 184.108.40.206.0