Numerical Simulations of Silverpit Crater CollapseThe Silverpit crater is a recently discovered, 60-65 Myr old complex crater, which lies buried beneath the North Sea, about 150 km east of Britain. High-resolution images of Silverpit's subsurface structure, provided by three-dimensional seismic reflection data, reveal an inner-crater morphology similar to that expected for a 5-8 km diameter terrestrial crater. The crater walls show evidence of terracestyle slumping and there is a distinct central uplift, which may have produced a central peak in the pristine crater morphology. However, Silverpit is not a typical 5-km diameter terrestrial crater, because it exhibits multiple, concentric rings outside the main cavity. External concentric rings are normally associated with much larger impact structures, for example Chicxulub on Earth, or Orientale on the Moon. Furthermore, external rings associated with large impacts on the terrestrial planets and moons are widely-spaced, predominantly inwardly-facing, asymmetric scarps. However, the seismic data show that the external rings at Silverpit represent closely-spaced, concentric fault-bound graben, with both inwardly and outwardly facing faults-carps. This type of multi-ring structure is directly analogous to the Valhalla-type multi-ring basins found on the icy satellites. Thus, the presence and style of the multiple rings at Silverpit is surprising given both the size of the crater and its planetary setting.
Document ID
20030111111
Acquisition Source
Headquarters
Document Type
Conference Paper
Authors
Collins, G. S. (Arizona Univ. Tucson, AZ, United States)
Turtle, E. P. (Arizona Univ. Tucson, AZ, United States)
Melosh, H. J. (Arizona Univ. Tucson, AZ, United States)
IDRelationTitle20030110578Collected WorksLunar and Planetary Science XXXIV: Papers Presented at the Thirty-Fourth Lunar and Planetary Science Conference March 17–21, 2003