The NW Rota volcano is located in the Mariana Volcanic Arc, about 100 km north of Guam at a depth of about 520 below sea level. NSF currently funds an scientific expedition to this active volcano; a scientific cruise to this site is currently occurring. The team are running a blog of their experiences and findings - it is here.
Yesterday they reported that in the time since their 2009 cruise the volcano has experienced a major landslide. The bathymetry data shows this rather well:
The landslide has caused up to 100 m of erosion from the summit area of the volcano (the blue areas on the map) and up to 40 m of deposition on the gentle lower slopes. These deposits extend for a distance of 8 km.