Activity |
Major Strombolian |
Dates of the explosion |
Beginning |
End |
|
May 25rd 2011 14:05:25 GTM |
Ballistic bomb velocities |
140-160 m s-1 |
Ballistic bombs height |
260-350 m |
Gas speed |
160-60 m s-1 |
FLIR thermal image sequence of the explosion of May 25, 2011 at 14h05 (GMT). The last image highlights the gas jet and the two bombs identified. The color scale ranges from black (25°C) to white (230°C).
Seismic displacement and velocity |
9.8 x10-6 m
2x10-4 m/s |
Acoustic pressure |
50 Pa (ROC station) 0.6 bar at the source |
Radiometer amplitude |
7.6 ° F |
Thermal Video |
|
a) 15 minutes long record at ROC station. The graph shows respectively the displacement (U/D), the pressure (Pr) and the thermal amplitude (Th) of the explosion (blue box) associated to the sampled rocks. b) The zoom of the 1 minute long of recorded trace containing the explosion. tsVLP, tsi, tsth are the onset, graphically showed with red dashed lines, of the chosen signal. Teth is the time at which the signals end.
Description |
Bombs from a normal Strombolian explosion |
Particle morphology |
Angular |
Particle size |
7-10 cm |
Particle weight
Particle density
Particle porosity |
1 Data table |
Particle glass chemistry |
1 Data table |
Minimum size of vesicles counted (pixel) |
10 |
Particle crystal content
Number of counted crystals x particle
Number of counted vesicles x particle
Particle 2D integrated vesicularity (%)
Particle Vesicle Number density |
1 Data table |