Low Frequency Hydrophone V16

The broadband seismometer (left) and low frequency hydrophone (right) are installed on the floor of Axial Seamount at the Central Caldera Site. The 7-function manipulator of ROPOS is connecting the extension cable to the medium powered junction box. The white bags inssulate the broadband from acoustic "noise" associated with curents flowing over the instrument.

Part of this detection and monitoring of seismic events  will be provided by low-frequency hydrophones (2 Hz to 20 KHz) that are well suited to detect the hydroacoustic tertiary phase of T waves of oceanic earthquakes. These sensors also detect solid-earth P waves from regional and teleseismic earthquakes. Coupled with the Ocean Bottom Seismometers, the low-frequency hydrophones will increase our ability to detect offshore earthquakes in real-time, determine their magnitude, and enable better location accuracy.

During VISIONS '14, low-frequency seismometers were installed in the central (MJ03F) and eastern (MJ03E) Axial caldera, and at Axial Base (MJ03A), Slope base (MJ01A), and Southern Hydrate Ridge Summit (LJ01B).