Recent Enhancements to the UCSB Geotechnical Array Data Portal

Instrumented geotechnical array field sites are designed to capture the infrequent but critically important in situ case histories of ground response, deformation, and liquefaction during earthquakes that generate high intensity ground shaking and large strains. The University of California at Santa Barbara (UCSB) has been monitoring densely instrumented geotechnical array field sites for almost three decades. UCSB provides access to the instrumental case histories generated by the earthquake recordings at these field sites through a web-based data dissemination portal (http://www.nees.ucsb.edu/data-portal). Currently the data portal provides access to more than 3,500 events of M3.0 and larger and over 350 events of M4.0 and larger. Once a particular site of interest has been chosen, the user can then create a search query using magnitude, date, distance ranges, and PGA to select earthquakes recorded by the site. A list of events is returned to the user along with an interactive Google-map showing the location of the events relative to the station. Once a particular earthquake has been selected, the user is then presented with a list of the waveform data available and the ability to either view thumbnails of the waveforms, or open an interactive waveform explorer tool within the web-browser window. In the waveform explorer, users may scroll through, filter, and zoom in and out on the data traces. Since this is done through the web browser, the tool is computer platform independent. The portal provides users with the ability to download data from the sites in a variety of common formats including miniSEED, SAC, COSMOS-V0, and CSV with an additional script for importing the data to MATLAB. In addition to the waveform data, the station metadata, including sensor calibration information, sensor layouts in map-view and cross-section, and site characterization information can all be downloaded from the portal. These metadata are critical to any future analysis of the ground motion or pore pressure records available from these sites. Most recently, the data portal has been enhanced to include processed and derived versions of the data for engineering seismology purposes, including COSMOS V2 (acceleration, velocity, displacement), V3 (response and Fourier spectra), Arias intensity, CAV, and effective amplitude spectrum.