Shortperiod Ocean Bottom Seismometer V17

Short-period seismometers provide real-time information on earthquakes at mid-ocean ridges. In 2003, an array of seismometers was deployed on the Endeavour Segment of the Juan de Fuca Ridge, north of Axial Seamount. The one shown here, was deployed inside a borehole in a pillow basalt in the Mothra Hydrothermal Field, providing better coupling to the seafloor. This project was funded by the W.M. Keck Foundation.

Deployment of short-period seismometers on the seafloor requires special consideration in terms of the sensors being level. Here, a special platform hosting the seismometer is being leveled by ROPOS through turning of adjustment bolts on the legs. These instruments will provide important real-time data on seismic activity inside the volcano, and associated with microfracturing events around the plumbing system for hydrothermal vents. VISIONS 13, Dive 1617

Photo credit: NSF-OOI/UW/CSSF

Short-period ocean-bottom seismometers (OBSSP) detect vibrations from small earthquakes ranging from 0.1 Hz to 100 Hz. These earthquakes are caused by local phenomena, such as melt movement beneath Axial Seamount and upward flow of hydrothermal fluids in the conduits that feed the black smoker chimneys. These instruments enable imaging of the seismic energy traveling through the seafloor.

Five short period seismometers are now installed at the summit of Axial Volcano at the Eastern Caldera subsite (MJ03E), and near the ASHES (MJ03B) hydrothermal field, and Central Caldera, and at the International Disrtic Hydrothermal Field (MJ03D).

Three short-period ocean-bottom seismometers are also installed at Southern Hydrate Ridge Summit (LJ01B) off of Newport Oregon.

All instruments are streaming data live to IRIS (Incorporated Research Institutions for Seismology) and are available to the public. Daily and hourly updates on the number of earthquakes occurring at Axial Seamount can be accessed through Dr. William Wilcock's web site.