No Further Impact Craters Greater Than 6 km Diameter Likely to be Found on Earth

The number of impact craters on Earth: Any room for further discoveries?

Authors:

Hergarten et al

Abstract:

Only 128 impact craters exposed at Earth's surface have been found so far, while new craters are discovered occasionally. Taking into account the permanent consumption of craters by erosion we present the first estimate on the number of impact craters that should be present at Earth's surface. Our study yields no evidence for any systematic incompleteness in the available inventory of the craters larger than about 6 km in diameter exposed at the surface. In contrast, more than 90 craters in the diameter range from 1 km to 6 km should still be waiting to be discovered, and even more than 250 between 0.25 km and 1 km diameter. The transition from a probably complete inventory above 6 km to a strongly incomplete record at smaller sizes may be related to the difference between simple and complex craters. Beyond these results on the terrestrial crater record, our findings tentatively suggest that erosion rates on the 10 to 100 million year scale may be closer to present-day erosion rates than previously assumed.