Rock Slab Growing at Mt. St. Helens Volcano

This is awesome - you can see "growth rings" from the marks of the debris line along the smooth edge.

Via: Flickr Title: Rock Slab Growing at Mt. St. Helens Volcano By: Guano
Originally uploaded: 10 May '06, 8.14am CDT PST
Photo Credit: Dan Dzurisin, Cascades Volcano Observatory, USGS
antwrp.gsfc.nasa.gov/apod/ap060509.html

A new rock slab is growing at more than one meter a day on the Mt. St. Helens volcano in Washington, USA. The rock slab, growing since last November, now extends about 100 meters out from one of the volcano's craters. A recently made time lapse movie shows the rock slab growing. Pictured above, a helicopter examines the steaming hot rock slab late last month. Mt. St. Helens underwent a spectacular eruption in 1980 but has been undergoing a comparatively serene eruption since 2004 September. A new volcanic dome has been building which is now about 100 meters above the 1980s dome. The rock slab is visible from the Johnson Ridge Observatory on the erupting volcano.

courtesy of NASA's "Astronomy Picture of the Day" for May 9, 2006.

note: full size photo is sweet...