The underwater Axial volcano (see Figure 1) erupted on April 24, 2015. The OO – Ocean Observatories Initiative network of Ocean-Bottom Seismometer (OBS) stations, equipped with hydrophones sensors, have been deployed in that area since 2014 and provide excellent opportunity to correlate microseism noise variations with changes in water pressure and ocean wave activities due to this eruption. This microseism energy quick look (MEQL) highlight provides a sample of such comparison utilizing seismic and hydroacoustic data from the AXBA1 and HYS14 stations of this network as well as standard meteorological data from the National Data Buoy Center.
The Secondary microseisms (SM) with periods between 2.86s and 10s are thought to be induced by pressure perturbations on the ocean bottom (Longuet-Higgins, 1950). This highlight looks at the SM variations and hydroacoustic pressure changes at two of the OO – Ocean Observatories Initiative (OBS) network stations deployed near this volcano (see Figure 1). The meteorological data collected by the buoy network of the National Data Buoy Center (NDBC) are also presented. These data cover April 20, 2015 through April 30, 2015 that encompasses the underwater Axial volcano eruption on April 24, 2015. The SM computations are performed using the IRIS noise Toolkit.
Figure 1. Map showing (green) location of the selected OO OBS network stations AXBA1 (from the western cluster) and HYS14 (from the eastern cluster), (yellow) location of the the National Data Buoy Center (NDBC) stations 46005 (to the west) and 46089 (to the east) and (red) location of the Axial volcano.
Figure 2. Temporal variation of the secondary microseism energy (at period band of 2.86s and 10s) at OO base station (AXBA1) near the volcano extending from 4 days before to 6 days after the eruption on 2015-04-24 (BHZ component in blue, BHN component in green and the BHE in red).
Figure 3. Temporal variation of the secondary microseism energy (at period band of 2.86s and 10s) at OO station (HYS14) near the shore extending from 4 days before to 6 days after the eruption on 2015-04-24 (BHZ component in blue, BHN component in green and the BHE in red).
Figure 4. Comparison of data near volcano (blue) and closer to shore (red): (top) temporal variation of SM median power of the BHZ channel with a moving 6hr smoothing window, (middle) hysdrophone pressure signals (period band of 2.86s to 10s) and (bottom) the NDBC buoy recorded significant wave height.
- Trabant, C., A. R. Hutko, M. Bahavar, R. Karstens, T. Ahern and R. Aster (2012), Data products at the IRIS DMC: stepping-stones for research and other application, Seismological Research Letters, 83(6), 846:854. https://doi.org/10.1785/0220120032
- Longuet-Higgins, M. S. (1950), A theory of the origin of microseisms, Philos. Trans. R. Soc. London, Ser. A, 243, 1–35.
- IRIS DMC Data Products Team