Cape EGS: Seismic Attenuation Profile and DAS Microseismic P-wave Spectra

This dataset contains a 1D P-wave attenuation (Q) profile, distributed acoustic sensing (DAS) microseismic P-wave spectra, and derived source parameters from the Delano 1OB well at the Cape Modern geothermal field. The data were collected during a stimulation period from mid-February to mid-March 2024 and include approximately 6,700 microseismic events. Frequency-independent Q values for the upper ~2.5 km are estimated using along-depth spectral ratios in the 20-200 Hz band, based on overlapping channel stacks. The dataset also includes well log measurements (e.g., density, P-wave velocity, and derived shear modulus) summarized using median and median absolute deviation statistics at each channel depth.

Microseismic source parameters are derived using a single-spectral fitting approach based on the Brune model, with event-level results reported as median values across selected channels that meet quality control criteria. The dataset further provides raw DAS P-wave arrival spectra calculated over 0.1 s windows, associated noise spectra, event origin times, and DAS channel configuration information, including spatial coordinates and depth conversion parameters. Python scripts are included to read, process, and visualize the data products. The methods used to compute attenuation and source parameters are described in Chang et al. (submitted), which will be linked upon publication: Chang, H., Nakata, N., Abercrombie, R. E., Dadi, S. & Titov, T. (submitted). Characterizing shallow attenuation and microearthquake source parameters using a downhole DAS array at the Cape Modern geothermal field.