Geologic history of Mauna Loa's submarine southwest rift zone (SWRZ)

Abstract

Using a combination of high spatial (~30 m) resolution multi-beam bathymetry and backscatter data collected in 2002, and underwater video footage and still images collected by Jason, we present a new geologic map and interpretations of the geologic history of Mauna Loa's submarine southwest rift zone (SWRZ). This study provides new insights on why the SWRZ's Western and Eastern flanks differ. The Western flank was sculpted by at least four stages of flank collapse, followed by ongoing volcanic activity and depositional processes (i.e., volcaniclastics generated by ocean entries). In contrast, the Eastern flank is distinctively rugged due to abundant constructional features (i.e., volcanic cones and pillow mounds). In addition, there is no clear evidence of any recent volcanism, suggesting that this portion of the flank has been inactive for quite some time.