Understanding the full nature and dynamics of the 1944 eruption is important not only because it was the last eruption at Vesuvius but also because recent research suggests that an eruption of a similar magnitude might be the most likely scenario for a future event at this volcano. The 1944 eruption happened immediately following the liberation of the region by the Allies toward the end of World War II, nevertheless there a number of contemporary accounts and extensive photographic documentation of this event. Until now there has, however, been no modern volcanological reconstruction of the 1944 event that attempts to fully integrate studies of the products of the eruption with the contemporary accounts. The products of this recent eruption are well exposed allowing correlation of distal tephra with ultra proximal deposits on the crater rim. The eruption began on the 18th March and lasted five days. Initially the eruption was effusive, with lava flows overtopping the crater rim in several directions. The explosive phase began as a series of eight discrete lava fountains which took place over a 24 hr period on the 21st March. The climax of the eruption took place on the 22nd March accompanied by intense seismicity. The explosive phase dispersed lapilli fall out mainly to the southeast, distal ash was recorded as far as Albania (500 km from the source). Initial lapilli, associated with fountains, was mainly composed of vesicular scoria whereas the paroxysmal phase included significant quantities of dense juvenile material. Later phases of explosive activity were ash-rich and were dispersed to the southwest. A new reconstruction of the distribution of the products and of the physical parameters associated with the different phases of the eruption allows us to classify this event as ‘subplinian', although it has previously been described as being ‘violent strombolian'. Small pyroclastic density currents (PDCs) were generated during the eruption however origin of these is enigmatic and there are conflicting theories as to how these were formed. We first describe the exposed products of these PDCs and discuss their potential origins.
The 1944 eruption of Vesuvius: a subplinian eruption? / Pd, Cole; Scarpati, Claudio. - (2008). (Intervento presentato al convegno IAVCEI 2008 General Assembly. Esplosive Volcanism Session tenutosi a Reykjavik, Iceland nel 18-25 August 2008).
The 1944 eruption of Vesuvius: a subplinian eruption?
SCARPATI, CLAUDIO
2008
Abstract
Understanding the full nature and dynamics of the 1944 eruption is important not only because it was the last eruption at Vesuvius but also because recent research suggests that an eruption of a similar magnitude might be the most likely scenario for a future event at this volcano. The 1944 eruption happened immediately following the liberation of the region by the Allies toward the end of World War II, nevertheless there a number of contemporary accounts and extensive photographic documentation of this event. Until now there has, however, been no modern volcanological reconstruction of the 1944 event that attempts to fully integrate studies of the products of the eruption with the contemporary accounts. The products of this recent eruption are well exposed allowing correlation of distal tephra with ultra proximal deposits on the crater rim. The eruption began on the 18th March and lasted five days. Initially the eruption was effusive, with lava flows overtopping the crater rim in several directions. The explosive phase began as a series of eight discrete lava fountains which took place over a 24 hr period on the 21st March. The climax of the eruption took place on the 22nd March accompanied by intense seismicity. The explosive phase dispersed lapilli fall out mainly to the southeast, distal ash was recorded as far as Albania (500 km from the source). Initial lapilli, associated with fountains, was mainly composed of vesicular scoria whereas the paroxysmal phase included significant quantities of dense juvenile material. Later phases of explosive activity were ash-rich and were dispersed to the southwest. A new reconstruction of the distribution of the products and of the physical parameters associated with the different phases of the eruption allows us to classify this event as ‘subplinian', although it has previously been described as being ‘violent strombolian'. Small pyroclastic density currents (PDCs) were generated during the eruption however origin of these is enigmatic and there are conflicting theories as to how these were formed. We first describe the exposed products of these PDCs and discuss their potential origins.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
