OREGON STATE UNIVERSITY

Floating Pumice – an Oceanic Hazard?

krakatoaeruption

 

Under water volcanoes, both shallow and deep, erupt more often than we think. When an exceptionally large underwater volcano erupts, the lava that is produced cools quickly, trapping gas bubbles within the rock. This forms pumice, a highly vesicular, highly porous rock that is light enough to float on water.

Large enough volumes of pumice can be violently ejected during eruptions, rising to the surface of the ocean to form floating rafts of pumice. Such pumice rafts have been seen after historical eruptions such as Krakatoa erupting in 1883, spewing pumice into the ocean and clogging harbors in Indonesia.

 

The Predicted Volcanic Eruption

Members of the Volcanic Risks Solutions team at Massey University in New Zealand have successfully predicted a volcanic eruption.  

A volcanic eruption of their creation, that is...!

Picture: The Volcanic Risks Solutions team; Shane Cronin,
Eric Breard (top), Dr Gert Lube and Professor Jim Jones with the Tower of Doom.


This team, led by Professor Shane Cronin and Dr Gert Lube, has created the world's first research project to investigate pyroclastic flows.


Pyroclastic flows are flows of a mixture of hot gas and particles that are emitted during a volcanic eruption, particularly like the eruptions found in New Zealand. 

A New Year, A Continuing Eruption

 

Mount Sinabung, a volcano located on the island of Sumatra, in Indonesia, is still erupting.

 

sinabung map

 

As one of the 129 active volcanoes in Indonesia, its current eruption started in September 2013 and has since erupted over several times a day. The initial eruptions of ash and lava have escalated into pyroclastic flows that have stretched kilometers out from the flanks of the volcano. 

 

sinabung pyroclastic flow
sinabung lava

 

The eruptions have displaced more than 22,000 people and have estimated to have cost almost US$60 million of damage in the surrounding crop lands as of the beginning of 2014. The current evacuation zone has been set by the government at a radius of 5 to 7 km from the volcano. 

 

 

 

 

As part of monitoring the eruption the Center for Volcanology and Geologic Hazard Mitigation has set up a webcam pointed at Mount Sinabung. Check out the live feed here: Sinabung WebCam