The video in the link below appears to be of a manhole in the middle of a highway erupting violently during a flash flood. It's remarkably reminiscent of Grand, including a three-minute pause (based on the time in the upper left corner) between bursts. I don't know where it is, but it appears to be authentic. I'm at a loss to explain the physics behind it if it is, though. http://www.bringmepie.com/video.php?id=3031 David Schwarz -------------- next part -------------- An HTML attachment was scrubbed... URL: </geyser-list/attachments/20070417/c8869fb9/attachment.html>