Boston's Big Picture does it's usual wonderfulness. http://www.boston.com/bigpicture/2010/04/more_from_eyjafjallajokull.html
--- In FairfieldLife@yahoogroups.com, "authfriend" <jst...@...> wrote: > > Excellent source for on-the-spot updates from the > Eruption in Iceland section of the Icelandic Met > Office Web site: > > http://en.vedur.is/earthquakes-and-volcanism/articles/nr/1884 > > Lots of links to detailed info on the ash cloud, seismic > activity, etc. > > Says there's *nothing* currently going on at either Hekla > or Katla. > > Best video (Windows Media Player) yet, IMO, of the > eruption: > > http://http.ruv.straumar.is/static.ruv.is/vefur/20042010_myndir_omar.wmv > > This was taken from a helicopter around 5 this morning > Iceland time. It's high-res, looking down into the crater. > Not spectacular in terms of huge fountains of lava and > lightning, but what's fascinating is how you can see the > *mechanics* of the eruption. When an explosion takes place > lower down in the crater, you can see "pressure waves" > from it radiating up into the billows of ash. A split-second > later, you see bits and pieces of incandescent lava thrown > up by the explosion. > > Unlike a wave in water, the pressure waves don't change > the shape or direction of the ash billows; apparently the > fact that the waves are visible at all is a phenomenon > having to do with the refractive index of the air, which > is made denser by the wave. Or something along those lines! >
