Open AccessExplosive Volcanic Eruptions—III. Plinian Eruption Columns
Author(s) -
Wilson L.
Publication year - 1976
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1976.tb06909.x
Subject(s) - peléan eruption , explosive eruption , geology , pyroclastic rock , phreatomagmatic eruption , vulcanian eruption , pyroclastic fall , dense rock equivalent , volcano , petrology , effusive eruption , magma , magma chamber , tephra , seismology , geophysics
Summary The mechanisms controlling the transport of pyroclasts in a plinian‐type eruption column are discussed. An estimate is made of the density of the magmatic gas in the vent, and initial (‘muzzle’) velocities are deduced for 18 eruptions using the a real distribution of pyroclasts in the resulting air‐fall deposits. A model of the physical properties of the lower part of an eruption column is presented, and used to deduce the heights to which plinian eruption columns should commonly extend. It is demonstrated that column collapse to form ignimbrites may be a common result of the change, with time, of the volatile content of the erupted material as progressively deeper levels in a magma chamber are tapped. Vent radii are estimated for those eruptions for which the duration of the eruption is known.