Publication Date:
2021-11-25
Description:
By injecting a mixture of gas and pyroclasts into the atmosphere, explosive volcanic eruptions frequently generate vortex rings, which are toroidal vortices formed by the jet's initial momentum. Here, we report high-speed imaging and acoustic measurements of vortex rings sourcing from gas-rich eruptive jets at Stromboli volcano (Italy). Volcanic vortex rings (VVRs) form at the vent together with an initial compression acoustic wave, VVRs maximum rise velocity being directly proportional to the amplitude and inversely proportional to the duration of the compression wave. The axial rise and acoustic signature of VVRs match well those predicted by recent fluid-dynamic experiments. This good match allows using the high-frequency (80-1,000 Hz) component of the jet sound and the time-dependent rise of VVRs to retrieve two key eruption parameters: the Mach number of the eruptive jets (〈1.5) and vent diameter (∼0.7 m), respectively, the latter being confirmed independently by direct Uncrewed Aerial Vehicle observations.
Description:
Published
Description:
e2021GL092899
Description:
5V. Processi eruttivi e post-eruttivi
Description:
JCR Journal
Keywords:
Stromboli; Strombolian; jet noise; vent diameter; vortex ring
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Permalink
