We have analyzed 291 shallow seismic events, leading to the July 17‐August 9, 2001 flank eruption at Mt. Etna volcano, to obtain high resolution three‐dimensional (3‐D) images of seismic attenuation of P waves (Qp) down to 2 km depth. 2293 P wave spectra have been inverted for seismic attenuation to calculate t* values, considering a frequency‐independent Q, and a ω2‐type source model. The 3‐D tomographic images reveal an anomalous region of very low Qp values (between 10 and 30), located in the same place where the 2001 dike emplaced. We interpret this anomaly as the effect of fluid intrusion (magma rich in gas) in the uppermost part of the Etna volcano, just before the 2001 eruption. This confirms that attenuation is a physical parameter sensitive to the thermal state of crustal volumes through which seismic waves travel.

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The addition of oxygenated renewable fuels, such as ethanol or ethyl tert-butyl ether (ETBE) to standard gasoline may be necessary to comply with some environmental directives but could also prevent compliance with some fuel regulations and could also seriously change engine performance. From this point of view, the Reid Vapour Pressure (RVP), the distillation curve, the oxygen content and the density belong to the group of the most relevant parameters. This study evaluates the influence of the simultaneous addition of ethanol and ETBE on some physical properties of engine gasoline. The main conclusion is that the simultaneous addition of ETBE and ethanol changes the RVP, the distillation curve and the density in a way that can affect engine operation and the mandatory EN 228 and ASTM D4814 standards. Some opposite properties of both oxygenates could help to increase the renewable energy content without preventing compliance with these regulations.