Skip to content

It is not easy being recognized as a greater crater

September 25, 2012

Earth is a dynamic planet – continents merge, collide and split; polar ice caps and glaciers contract and expand; oceans ebb and flow. Then there are volcanic eruptions, asteroid impacts, and humans busily digging mines and paving parking lots. The largest impact craters discovered so far are shown below (diameter in kilometers; note Popigai outlined in red) are almost all are entirely on land, which likely means lots of large craters below the ocean surface. How long a deep water crater would be recognizable is a matter of lively debate. They are without doubt far more expensive to analyze.

The four asterisks are explained by the fine folks at the Earth Impact Database as follows:

‘This revised diameter is the best estimate for the collapsed transient crater diameter (rim-to-rim dimension). Our previous diameters cited maximum damage diameter estimates. There is considerable confusion in the literature regarding the definition of “diameter”. In the Earth Impact Database, we are striving to cite the collapsed transient crater value where possible. This can affect the order of size: for example, Sudbury’s maximum damage diameter is ~260 km (as defined by the outermost ring diameter), while that of Chicxulub is ~240 km. However, the rim-to-rim diameter of Sudbury is less than that of Chicxulub’s (130 versus 150 km, respectively).’

By any measure, Popigai is BIG. Can a planet our size suffer that kind of impact and not be profoundly changed?

 

 

 

Advertisements

From → Impact craters

Leave a Comment

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: