How do volcanic rift zones relate to flank instability? Evidence from collapsing rifts at Etna
Article first published online: 24 OCT 2012
©2012. American Geophysical Union. All Rights Reserved.
Geophysical Research Letters
Volume 39, Issue 20, 28 October 2012
How to Cite
2012), How do volcanic rift zones relate to flank instability? Evidence from collapsing rifts at Etna, Geophys. Res. Lett., 39, L20311, doi:10.1029/2012GL053683., , , , , , and (
- Issue published online: 24 OCT 2012
- Article first published online: 24 OCT 2012
- Manuscript Accepted: 14 SEP 2012
- Manuscript Revised: 13 SEP 2012
- Manuscript Received: 25 AUG 2012
- volcanic rift
 Volcanic rift zones, characterized by repeated dike emplacements, are expected to delimit the upper portion of unstable flanks at basaltic edifices. We use nearly two decades of InSAR observations excluding wintertime acquisitions, to analyze the relationships between rift zones, dike emplacement and flank instability at Etna. The results highlight a general eastward shift of the volcano summit, including the northeast and south rifts. This steady-state eastward movement (1–2 cm/yr) is interrupted or even reversed during transient dike injections. Detailed analysis of the northeast rift shows that only during phases of dike injection, as in 2002, does the rift transiently becomes the upper border of the unstable flank. The flank's steady-state eastward movement is inferred to result from the interplay between magmatic activity, asymmetric topographic unbuttressing, and east-dipping detachment geometry at its base. This study documents the first evidence of steady-state volcano rift instability interrupted by transient dike injection at basaltic edifices.