Abstract and Poster presented at American Geophysical Union Mtg. San Francisco, Ca. 13 December 2010

Supervolcanoes in the Mid-Pacific Mountains?

Pat Wilde
Pangloss Foundation
Berkeley, Ca

Sea floor physiographic reconstructions from satellite gravity show crater like features in the Mid-Pacific Mountains of the Central Pacific Ocean. These features are not seen on conventional bathymetric charts in the area due to sparse trackline information. Up to seven huge craters, treading in a southeast northwest direction are seen, some several hundred miles in diameter. Some craters are nested and the area looks similar to the lunar surface. The water depth is in excess of 5000 meters. Water depth makes progressive impacts unlikely. A possible analog is an oceanic supervolcanic belt, like Yellowstone. The craters decrease in size from the southwest, suggesting waning hot spot activity to the northwest with time. The intermediate composition of some of rocks from the surveyed seamounts suggest the result of hot spot activity may be different from usual linear seamount formation on typical oceanic crust. Some seamounts that rim the craters in the north are dated to about 90 Myrs and the sea floor in the region is one of the oldest known at 180 Myrs. Thus the age of the formation is Jurassic into the Cretaceous. The rate of progression and the timing can not be determined at this time as there are very few dated seamounts that rim the craters.

Power Point of Poster