Mount St. Helens
Magma bubbles came to the top of the volcano on about October 11, 2004, and a new lava dome was made on the first dome's south side. This new dome grew throughout 2005 and into 2006. Several new features were seen, such as the "whaleback," which is solid magma being pushed to the top of the volcano by magma under it. These features do not last long and break down soon after they are formed. On July 2, 2005, the tip of the whaleback broke off, and a rockfall sent ash several hundred meters into the air.