Figure 3From: Characterization of ambient seismic noise near a deep geothermal reservoir and implications for interferometric methods: a case study in northern Alsace, France Beamforming analysis performed on the Soultz-sous-Forêts network. About 4 years of data have been divided up into 15-min windows and filtered around 1s. Top: probability density function (color code) of the estimated phase speed (expressed in km/s and displayed as the radius) and back azimuth (measured clockwise from the north in degrees) of the noise. Bottom: detail of the variation of the dominant back azimuth measured using the 4 years of data grouped by month (all January months together, etc.). Error bars delimitate the 16% and 84% percentiles of the statistical distribution of detected back azimuths.Back to article page