Search

From October 2008 until present dozens of small impulsive explosive eruptions occurred from the Overlook vent on the southeast side of Halemaumau Crater at Klauea volcano USA. These eruptions were triggered by rockfalls from the walls of the volcanic vent and conduit onto the top of the lava column. Here we use microtextural observations and data from clasts erupted during the well characterized 12 October 2008 explosive eruption at Halemaumau to extend existing models of eruption triggering. We present a potential mechanism for this eruption by combining microtextural observations with existing geophysical and visual data sets. We measure the size and number density of bubbles preserved in juvenile ejecta using 2D images and X ray microtomography. Our data suggest that accumulations of large bubbles with diameters of >50 m to at least millimeters existed at shallow levels within the conduit prior to the 12 October 2008 explosion. Furthermore a high number density of small bubbles