Direct measurements
(18):
Acoustic records
Formation of a basaltic plume
height > 16 km
Eruption finishes with
Strombolian activity
(a series of large bubbles
breaking)
Basaltic
plume is very rare
Plume = very analogous to explosive eruptions
Acoustic measurements
origin of basaltic Subplinian
activity
transition Subplinian- Strombolian
Shishaldin 23/04/99
30 % of volcanoes in
subduction
zone are basaltic (basaltic
andesite)
Shishaldin,
Alaska, USA