Publication Date:
2019-09-23
Description:
Ocean island volcanoes frequently develop local rift zones associated with flank movement
and flank collapses. The ocean island El Hierro grew by coalescence and collapse of three volcanic
edifices, which are an elongated topographic ridge (the Southern Ridge) and two semi-circular volcanic
cones (Ti˜nor volcano, El Golfo volcano). During edifice growth and volcano coalescence, eruption
fissures nucleated into rift zones that developed a complex triangle pattern. In scaled analogue
experimentswe could successfully reproduce the geometry of rift zones and unstable flanks as observed
on El Hierro. The experimental results suggest that the rift configuration on El Hierro is the result of
gravitational volcano spreading over deformable basal substrata, rather than of deep-seated magma
updoming as thought previously. This paper elucidates the importance of the basal substratum and
gravitational spreading, and the relationship to rifting and flank instability on El Hierro Island, and
may help in understanding similar volcano architectures elsewhere.
Type:
Article
,
PeerReviewed
Format:
text
