Don Yon...

[Baradium]

http://www.msnbc.msn.com/id/18679654/

"NASA robot to explore 'bottomless' pit
Self-automated submarine will search the depths of the El Zacaton cenote"

See the link for more...

If they don't know how deep it is, how do they know it's a sinkhole?

Somewhat related: there's a volcanic lake in California I believe that they used to not know the depth of, anyone know if they ever did sonar readings to get one?



Any more information?

[airtac]

Would that be Lake Tahoe?  It used to called "bottomless" but was finally measured at about 1650 feet deep----Crater Lake in Oregon is deeper at about 2,000 feet--don't know of any other deep lakes around here.

[Gulfstream Driver]

Devil's Kettle is in the middle of the Brule River on the North Shore of Lake Superior.  The river splits in two, with one half going over a waterfall and the other falling into a hole in the bedrock.  As far as I know, they've never been able to find where the water ends up.  It's really impressive, if you're up for a pretty good hike through MN mountain country. 

http://www.dnr.state.mn.us/state_parks/judge_cr_magney/index.html
http://www.gowaterfalling.com/waterfalls/devilskettle.shtml

The picture in the second link shows the waterfall on the right and the kettle on the left.  It's pretty awesome to see in person.

[Baradium]

These days you'd think they'd stick something with a homing signal down it.... 

[airtac]

That's impressive!
I see they tried dyes with no results---Egads, imagine some hot dog kayaker getting swept over into the pit--agh! what a scary scenario

[Gulfstream Driver]

These days you'd think they'd stick something with a homing signal down it.... 

I think they did.

[Baradium]

These days you'd think they'd stick something with a homing signal down it.... 

I think they did.

Don't suppose you found a link?