Susan Russell-Robinson of the U.S. Geological Survey said partial aerial views Thursday indicated that the lava dome that squeezed through a hole in the floor of the crater remained unchanged in size.
She said the dome has started to sag and lookes like an overbaked muffin.
The dome pushed up through the volcano's small 'inner crater' following a three-day eruptive phase that started Oct. 16. It was the sixth major eruption since the volcano ended 127 years of dormancy last March and the fifth since the gigantic May 18 blast tore a cubic mile off the top of the mountain.
Ms. Russell-Robinson said the dome's sagging was first noticed Sunday evening, indicating the dome stopped growing that day.
The dome's dimensions have stabilized at about 155 feet in height and 900 feet across. It is the third dome to appear in the volcano's 'inner crater' since it became active. The first two were destroyed by eruptions.