Diamonds Linked to Quick Cooling Eons Ago

NY Times ^ | January 2, 2009 | KENNETH CHANG

[Captain Beyond]

bump

[aculeus]

Cool!

[norwaypinesavage]

Eons ago? 13000 years isn’t even roundoff error on the “eon scale”.

[supercat]

How can "less dense" fresh water block the sinking of cold, salty water? Higher density fluids sink relative to other fluids. Is this New York Slimes science, or am I missing something?

If a layer of salt water sits beneath a layer of fresh water, convection will be far less effective than it would be if all water were of uniform salinity. The article's terminology is weird, however, since the salt water wouldn't be stuck on the surface but rather below.

Incidentally, ice is nearly always frozen fresh water; the act of freezing pushes out the salt. This could create variations in salinity, though in most cases natural mixing would prevent them from becoming too significant.

[Lee N. Field]

The big question is: where's the crater(s)?

There's plenty of craters. Earth Impact Database. (Interesting website to peruse. Just FYI, the biggest is the Vredefort ring, in South Africa. 300km across.)

[neverdem]

Thanks for the ping. Happy New Year!

[Pharmboy]

Thanks for the data...good addition to this thread.

[Smedley]

If a layer of salt water sits beneath a layer of fresh water, convection will be far less effective than it would be if all water were of uniform salinity. The article's terminology is weird, however, since the salt water wouldn't be stuck on the surface but rather below.

This I understand, but the scenario is supposedly a layer of fresh water sitting beneath a layer of salt water not allowing the salt water to sink.

This isnt an issue of "terminology" but one of a complete screwup of the description of circumstances.