The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
During short lived volcanic eruptions, dilute, turbulent pyroclastic density currents are often observed to spread laterally from a collapsing fountain. These flows entrain and heat air while also sedimenting particles. Both processes lead to a reduction in the bulk density and since these flows often become vertically stratified, the upper part of the flow may then exhibit a reversal in buoyancy...