Slope failure and volcanic spreading along the submarine south flank of Kilauea volcano, Hawaii

Abstract

[1] New multichannel reflection data and high-resolution bathymetry over the submarine slopes of Kilauea volcano provide evidence for current and prior landsliding, suggesting a dynamic interplay among slope failure, regrowth, and volcanic spreading. Disrupted strata along the upper reaches of Kilauea's flank denote a coherent slump, correlated with the active Hilina slump. The slump comprises mostly slope sediments, underlain by a detachment 3-5 km deep. Extension and subsidence along the upper flank is compensated by uplift and folding of the slump toe, which surfaces about midway down the submarine flank. Uplift of strata forming Papa'u seamount and offset of surface features along the western boundary of Kilauea indicate that the slump has been displaced $3 km in a southsoutheast direction. This trajectory matches coseismic and continuous ground displacements for the Hilina slump block on land, and contrasts with the southeast vergence of the rest of the creeping south flank. To the northeast, slope sediments are thinned and disrupted within a recessed region of the central flank, demonstrating catastrophic slope failure in the recent past. Debris from the collapsed flank was shed into the moat in front of Kilauea, building an extensive apron. Seaward sliding of Kilauea's flank offscraped these deposits to build an extensive frontal bench. A broad basin formed behind the bench and above the embayed flank. Uplift and back tilting of young basin fill indicate recent, and possibly ongoing, bench growth. The Hilina slump now impinges upon the frontal bench; this buttress may tend to reduce the likelihood of future catastrophic detachment.

Bathymay : la structure sous-marine de Mayotte révélée par l'imagerie multifaisceaux

“…The decompression generated by the normal faults to the northwest and by gravity collapse to the southeast probably influenced the concentration of the recent eruptive activity in these sectors; such features are observed in the Canaries islands and along the Kilaua volcano in Hawaii [1,19].…”

“…Un petit glissement est relevé à l'Ouest au Les glissements sous-marins sont des phénomènes destructifs qui affectent couramment les édifices volcaniques comme la chaîne hawaiienne [18], les Canaries [1], la Polynésie [6] ou La Réunion par exemple [15,21]. Plusieurs mécanismes sont invoqués à l'origine des glissements, dont les intrusions massives de dykes [11,14,19], les augmentations des valeurs de pentes en stade post-bouclier [25], les vibrations des séismes [23] [27] comme une ancienne caldeira aérienne d'axe N140°. À terre, cet appareil comporte principalement des laves basaltiques mio-pliocènes et des pitons de phonolites pliocènes [7].…”

Volcano‐tectonic implications of 3‐D velocity structures derived from joint active and passive source tomography of the island of Hawaii

“…Even so, the source areas for these landslides were often difficult to identify because subsequent lava flows and slope sediments filled in the scars [e.g., Lipman et al, 1988]. Additionally, lateral spreading and deformation of Hawaiian volcanoes throughout their evolution means that volcanic rift zones may evolve over time [Swanson et al, 1976;Dieterich, 1988;Denlinger and Okubo, 1995;Morgan et al, 2003]. Constraining the past configurations of volcanoes and their rift zones is the key to unraveling the growth history of the island [Fiske and Jackson, 1972;Holcomb et al, 2000], and also provides insight into the present-day deformation of the volcanoes, i.e., ongoing surface movements and earthquake activity [Denlinger and Okubo, 1995].…”

Morphological and structural analysis in the Anaga offshore massif, Canary Islands: fractures and debris avalanches relationships

“…At the Cordillera Dorsal an 8-9 km wide valley was formed, with an amphitheatre-shaped head, an area of 73 km 2 and prominent side walls. The origin of this Güimar Valley was interpreted by Navarro and Coello (1989) to be the result of landslide processes, the same origin as for the Orotava Valley (Figure 2). Geological studies of Güimar Valley showed that it was formed by a flank collapse younger than 0.83 Ma, the most recent age obtained for lava flows in the scarp (Ancochea et al, 1990).…”

“…Day et al (1999) described the well developed topographic San Andrés fault scarp on the flank of the steep-side NE rift of El Hierro, and related it to an aborted giant collapse; Vidal and Merle (2000) used a model to prove that the reactivation of a vertical fault in volcanic cones generates normal faults and an upturning of the layers that induces a flank collapse. In Hawaii, the Hilina slump has been recognized as an active landside that breaks the mobile southeast flank of Kilauea volcano and is headed on land by a system of seaward facing normal faults (Morgan et al, 2003). From the study of the characteristics of this scarp, its relation with the on-land features of Güimar Valley and the comparison with other avalanches in the Canaries, we suggest that a tectonic process seems to have created the scarp.…”