The Haiti tsunami

The State of the Planet blog, which is the blog of the Earth Institute at Columbia University, reports on an ongoing investigation of the tsunami that killed a small number of people to the west of Port-au-Prince (image below from the National Geographic).

The research has involved drilling cores into the sediment on the sea floor near to the tsunami. Their initial analysis suggests that the tsunami was caused by a lateral spread near to the coastline, which released a flow down the offshore slope into deeper water. It is this submarine landslide that was probably responsible for the localised tsunami.

They promise more analysis in the coming days, so watch this space.

A new submarine landslide at NW Rota, near Guam

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.