Surveying Brothers volcano voyage update
Co-principal investigator onboard the RV Sonne, Cornel de Ronde provides an update on the recent surveying of Brothers volcano.
"For the past 2 weeks the Sonne and scientists onboard have been focused on firstly completing a 2D seismic survey of Brothers volcano (Figs, 1 and 2) and Healy volcano 14 km to the south (Figs. 1 and 3), followed by completing a 3D ‘seismic box’ between Brothers and Healy. In total, about 5,000 line-km of seismic lines were shot during both surveys.
The 2D sections provide context for the 3D seismic sections that will ultimately help elucidate the internal architecture of these volcanoes and their relative stratigraphy. Already, we have seen complicated relationships between caldera collapse, resurgent cone growth, and everything in between. These data will go a long way in expanding our knowledge on the formation of submarine arc volcanoes, many of which are associated with seafloor hydrothermal systems and associated mineral deposits.
In between the 2D and 3D seismic surveys the Sonne steamed south to conduct bathymetric, gravity and magnetic surveys over Rumble II West volcano, 60 km south of Healy, and then Rumble III volcano, 40 km further south again.
Presently, we are shooting with large air-guns to help image the deep subseafloor (to ~35 km) where we hope to gain insight into the location of magma chambers beneath Brothers and Healy volcanoes and visualize the crust from the seafloor down to the Moho. Once completed, the last task is to recover the 24 OBSs (ocean bottom seismometers) from the seafloor, then steam back to Auckland to disembark scientists and crew before the next voyage begins".
