The First Network of Ocean Bottom Seismometers around Jøtul Hydrothermal Vent Field, Knipovich Ridge

Abstract

Ultraslow spreading ridges are a vital part of mid-ocean ridge systems, consisting of both magmatic and amagmatic spreading segments. Hydrothermal vents play a key role in the transfer of matter and heat from the lithosphere to the hydrosphere and biosphere. However, research on the relationship between magmatism, faulting, and hydrothermal circulation beneath vent fields on ultraslow spreading ridges is still limited. Here, we investigate Jøtul vent field, situated on a magmatic segment of Knipovich Ridge. We provide continuous passive seismic data recorded by a network of up to 15 broadband ocean bottom seismometers covering up to 50 km along-axis and the time from July 2023 to August 2024. We present our correction for nonlinear clock drift using ambient noise cross-correlation and sensor orientation from Rayleigh wave polarization analysis. Probabilistic power spectral density plots show a clear double-frequency microseismic noise peak. Noise bands at periods of 0.2-0.4 s are likely related to sediment layers and ocean currents. Vibrations of the radio beacon antenna produce noise at periods of 0.16 s. Despite this ambient seismic noise, transient signals of teleseismic, regional, and local earthquakes, and air-gun signals are clearly visible in the dataset enabling studies of seismicity and seismic structure.