Pacific Ocean Disasters

Pumice rafts are an occasional byproduct of explosive volcanic eruptions that occur near bodies of water. Rafts can be tens of
kilometers across and are a hazard to shipping, as the pumice can block the seawater intake valves for ships’ engine cooling
systems. In particular, this research focuses on pumice rafts that emanated from the eruptions near Tonga in 2006, Yemen in 2007,
and the Chile-Argentina border in 2011 using data from Landsat 5 & 7, MODIS onboard the Aqua and Terra satellites, and ALI aboard
the EO-1 satellite. False color composites were created to facilitate visual identification of pumice rafts in high resolution images.
Additionally, a material of interest subpixel classification was implemented to automatically demarcate the extent of the pumice rafts.
MODIS was found to be the most useful sensor for tracking larger rafts in the open ocean, while Landsat 5 & 7 and ALI were more
effective in tracking smaller rafts in lakes and rivers. The pumice rafts generally took on a temperature between that of the ambient
air and water temperature. The data collected for this study has been compiled to provide an effective tool for further investigation of
pumice rafts.