High-resolution magnetic data collected along the axis and the south flank of the Puna Ridge, the submarine extension of the East Rift Zone of Kilauea Volcano, Hawaii, aid in the interpretation of magmatic processes. Crustal magnetization varies along the crest of the Puna Ridge. Three prominent magnetization highs are located between the depths of 1500 and 2500 m. Each of the magnetization highs is associated with distinct volcanic features: a flow field on top of fissured terrain, a lava plateau, and a staircase of lava terraces. The crustal magnetization highs can be explained by the presence of these volcanic features, taking into account water depth and the size of the volcanic features and making simple assumptions about the rock magnetization. No measurements of rock magnetization have been made on Puna Ridge samples. We assume two values: 50 and 10 A/m, based on values from mid-ocean ridge basalts and the estimated ages of Puna Ridge rocks [Clague et al., 1995]. The two shallowest magnetization highs are adjacent to a landslide scarp. Lava flows overtop the scarp suggesting that a dike has been emplaced and eruptions have occurred since the landslide formed. A possible scenario is that the collapse of the flank led to dike intrusion and eruption at this location because of a reduction in the horizontal stress within the edifice. Our observations suggest that flows are starting to fill in the gap caused by the landslide to rebuild this section of the north flank.
ASJC Scopus subject areas
- Geochemistry and Petrology
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science