Investigating the nature of an ash cloud event in Southern Chile using remote sensing: volcanic eruption or resuspension?

On 14 December 2013, the Cooperative Institute for Meteorological Satellite Studies (United States) reported a volcanic ash cloud apparently emitted by the Puyehue Cordón Caulle Volcanic Complex (Chile) and indicated its cause was probably resuspension. The distinction of volcanic ash resuspension from volcanic eruptions is important because both processes pose different scenarios for civil protection authorities and besides, there is a special need of specific schemes for detecting and monitoring resuspension of volcanic ash. To this end, we intended to identify the cause of this event by using remote sensing technology. Remote sensing based volcanic ash products enabled us to confirm the presence of volcanic ash and observations on the Moderate Resolution Imaging Spectroradiometer (MODIS)–based cloud-integrated water path provided evidence in favour of a small and short-lived eruption. Thus, a volcanic eruption would constitute a plausible explanation for the cloud of 14 December 2013, but we were unable to discard resuspension. On the other hand, we found out that the water path product could constitute useful ancillary data to identify the origin of this kind of processes. The set of observations presented constitutes a good initial point towards the identification and subsequent development of decision support tools for the mitigation of the hazards posed by volcanic ash resulting from volcanic eruptions and resuspension.