Catastrophic volcanic activity at Rumble III volcano based on EM300 bathymetry and direct seafloor imaging
The Kermadec-Tonga Arc, located between New Zealand and Fiji, hosts numerous submarine volcanoes generated by the collision of the Pacific and Australian plates. Rumble III volcano, located along the arc 300 km northeast of the Bay of Plenty, New Zealand, is known to be hydrothermally active as documented by a plume rising from the summit area; however, little research has been conducted at this volcano. This study, conducted on March 9-11, 2009 aboard the R/V Thomas G. Thompson during a University of Washington student research cruise, investigates the geology of Rumble III volcano and its volcanic activity. High-resolution submarine bathymetry and imagery collected with a deep towed camera system show striking differences compared to prior investigations. The summit has collapsed and is now 100 m deeper than last recorded in 2007, the adjacent 800 m wide caldera has almost completely filled in, and much of the side of the volcano has fallen away. Volcanic deposits that include lava flows and ash were documented throughout the images from the deep towed camera taken from two runs conducted at and surrounding the summit of the volcano. In concert, these observations indicate a recent catastrophic volcanic eruption has occurred at Rumble III volcano in the past two years and highlight the dynamic nature of volcanoes in the Kermadec Arc.