VANCOUVER - A small earthquake, followed by a steam and ash plume, was reported at Mount St. Helens late Friday night.

The quake, probably caused by a large rockfall in the southwest Washington volcano's crater, was recorded at 9:05 p.m. PDT, the U.S. Geological Survey said in a statement.

An airline pilot soon reported that a plume of steam and ash had risen to an altitude of about 15,000 feet, the USGS said.

A similar event on May 29 melted some snow and ice in the crater and also sent up a plume to about the same altitude.

Seismic activity at the mountain quickly returned to normal.