11:24 AM PDT on Friday, August 19, 2005

By kgw.com and AP Staff

VANCOUVER, Wash. -- Observers at Mount St. Helens reported seeing an intense glow and vertical column over the volcano Thursday night -- a sight that lasted several minutes beginning around 9:20. p.m.

USGS volcanocan photo

A small steam cloud still hovered over Mount St. Helens as the sun came up early Friday morning.

The sighting from nearby Coldwater Ridge corresponded with two rockfall signals recorded by seismometers. Another rockfall was associated with a magnitude 2.9 earthquake at about 10 minutes to 11 p.m.

Photographs from a camera on the mountain show that the volcano's new lava spine continues to grow as a formerly active spine sags and collapses. The activity is expected to produce continued rockfalls and associated ash plumes -- and, at night, light shows.

The mountain - site of a deadly eruption in 1980 - had been quiet for several years. It rumbled back to life last fall and resume building a lava dome in its blasted crater. The activity can cause short-lived explosions that can send ash clouds as high as 30,000 feet. Ash from these events can travel as much as 100 miles downwind.

The mountain's pattern over centuries has been to pile up layer upon layer of lava. Before the 1980 eruption, Saint Helens's snow-capped peak was so symmetrical it was called America's Mount Fuji.

The mountain is being monitored by scientists with the U.S. Geological Survey and the University of Washington.