The New IRIS DMC Noise Toolkit
Manoch Bahavar, Alex Hutko, Chad Trabant, Keith Koper, Rob Anthony, Rick Aster
The IRIS Data Management Center (DMC) products team highlights a new Noise Toolkit product currently in development that will be based on hourly power spectra calculated for broadband (BH) channels at hundreds of stations. The Noise Toolkit will be used to 1) compute polarization attributes of noise to gain more insight into the propagation mode of the ambient noise and 2) perform microseism energy computation to reveal coherent variability of microseism noise at the stations as well as those caused by major storms. The polarization analysis includes eigen-decomposition of a sliding one-hour spectra covariance matrix of three-component broadband seismic data to gain insight into the propagation mode of the ambient noise by providing information on the phase relationships between different components. The near real-time microseism index database contains various metrics such as 6 hours, 1 day, 4 days, and 16 days medians based on PSDs as well as many other metrics. Plots as well as monthly summaries will be readily accessible and ripe for data mining as interest in seismic noise studies has steadily grown in recent years by researchers in seismology and other disciplines. This toolkit will have many applications such as generating ‘weather maps’ of seismic noise among others.
Bahavar, M., A. R. Hutko, C. M. Trabant, K. D. Koper, R. E. Anthony, R. C. Aster, The New IRIS DMC Noise Toolkit, Fall Meeting of the American Geophysical Union, San Francisco, CA, December, 2013.