Lava dome
Appearance
![](http://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/MSH06_aerial_crater_from_north_high_angle_09-12-06.jpg/300px-MSH06_aerial_crater_from_north_high_angle_09-12-06.jpg)
In volcanology, a lava dome or plug dome is a round-shaped mound created by the eruption of viscous lava by a volcano.
Lava domes are formed when erupting lava is too thick to flow and makes a steep-sided mound as the lava piles up near the volcanic vent. Lava domes have formed in Mount St. Helens and experts say a lava dome is growing inside the Shinmoedake volcano in Japan.