Overthrusting and sediment accretion along Kilauea's mobile south flank, Hawaii: Evidence for volcanic spreading from marine seismic reflection data

Morgan, Julia K.; Moore, Gregory F.; Hills, Denise; Leslie, Stephen

doi:10.1130/0091-7613(2000)28<667:oasaak>2.0.co;2

Cited by 100 publications

(74 citation statements)

References 13 publications

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“…One of the most prominent sets of reflections identified on the MCS sections occurs between 5 and 6 s TWTT beneath the outer bench and can be followed to $5 s and less beneath the upper flank and Papa'u seamount. The depth of this reflection below the seafloor, its projection beneath sediments within the Hawaiian Deep (e.g., Figure 3b), and its continuity across the flank indicate that this reflection lies near the top of Cretaceous oceanic crust and its sediment cover [Morgan et al, 2000;Leslie et al, 2002]. Based on structural geometries within the outer bench, Hills et al [2002] found the strongest reflection just above and parallel to the oceanic crust to be a basal decollement, D, upon which the mobile south flank of Kilauea slides seaward [e.g., Nakamura, 1980;Denlinger and Okubo, 1995].…”

Section: Results and Interpretation 421 Top Of The Oceanic Platementioning

confidence: 99%

“…This construction resembles the anticlinal ridge produced by volcanic spreading, envisioned by Borgia and Treves [1992]. The two bench crossing reflection lines, Lines 15 ( Figure 10b) and 21 (Figure 10a) reveal seaward verging thrust faults rising from a gently dipping, subedifice decollement D. In our study area, D lies about 1 km above the top of oceanic crust and probably rides along the top of buried pelagic and clastic sediments [e.g., Nakamura, 1980;Denlinger and Okubo, 1995;Morgan et al, 2000;Leslie et al, 2002]. The thrust faults that built the outer bench (e.g., T 1 , T 2 , etc.)…”

Section: Midslope Basin and Outer Bench Domainmentioning

confidence: 99%

“…Several previous papers describe observations across the distal regions of the submarine flank and Hawaiian Moat [Morgan et al, 2000;Hills et al, 2002;Leslie et al, 2002]. Here we focus on several seismic reflection profiles that cross the upper flanks and southwestern margin of Kilauea's mobile flank, to delineate the geometry and evolution of the Hilina slump.…”

Section: Seismic Reflection Datamentioning

confidence: 99%

“…A distinct set of middepth reflections, labeled G 1 , occurs between 1 and 2 s below the seafloor on both Lines 22 and 15; the internal G 1 reflections do not intersect either seafloor or decollement, but tend to bound unconformable sequences of layered strata, discussed in detail below. Line 15 displays a series of landward dipping reflections that rise from D beneath the lower reaches of the upper flank and midslope bench (SP 400-800); these correspond to frontal thrust faults that have been described previously [Morgan et al, 2000;Hills et al, 2002], and are labeled according to their proximity to the island, i.e., T 1 , T 2 , and T 3 . [28] To the east of the break in slope, well expressed on Line 23, seafloor depth increases across the central bathymetric embayment.…”

Section: Seismic Stratigraphymentioning

confidence: 99%

“…[24] The seismic characteristics of the MCS sections across the study region help to resolve three compositional domains ( Figure 3): a region of high-frequency, slopeparallel reflections extending up to 1 s below the seafloor, presumed to consist of fragmental subaerially erupted lavas forming a thin blanket of bedded slope sediments; a deeper, less reflective zone above the strong D and OC reflections, characterized by discrete low-frequency and reverberant reflections, defining the primary volcanic edifice composed of submarine erupted pillow basalts; and a frontal domain corresponding to the midslope bench and basin (e.g., Line 15, SP 500 -900), composed largely of volcaniclastic debris [e.g., Morgan et al, 2000;Lipman et al, 2002].…”

Section: Seismic Stratigraphymentioning

confidence: 99%

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

2003

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[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.

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Section: Results and Interpretation 421 Top Of The Oceanic Platementioning

confidence: 99%

Section: Midslope Basin and Outer Bench Domainmentioning

confidence: 99%

Section: Seismic Reflection Datamentioning

confidence: 99%

Section: Seismic Stratigraphymentioning

confidence: 99%

Section: Seismic Stratigraphymentioning

confidence: 99%

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

2003

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Deformation of basaltic shield volcanoes under cointrusive stress permutations

2014

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We performed a microstructural study of Piton des Neiges (La Réunion Island) to understand how intrusions and stresses control each other in basaltic volcanoes. Our study reveals that three perpendicular intrusions trends coexisted during the 2 Myr history of the volcano: a N120-140°E rift zone, a perpendicular dike trend, and swarms of subhorizontal intrusions hereafter called "sill zones". Independently, the inversion of fault-slip data shows that incompatible paleostress fields recurrently occurred along with the intrusions: a dominant NNE-SSW extension, a perpendicular extension, and strike-slip or compressional regimes. The orientations of paleostresses are consistent with the orientations of the three perpendicular intrusion populations. We propose that stress accumulation in the edifice under the effect of repeated magma injections resulted in permutations of the principal axes of the stress tensor, causing a reorientation of subsequent intrusions. Stress permutations were cyclical. Each cycle started with dike injections in an extensional stress field, reducing the deviatoric stress and switching the axes of principal stresses, and finished with sill intrusions in a compressional stress field. Sill zones acted as detachment planes, restoring the extensional stress field and initiating a new cycle of permutations. Our model of stress permutations is in agreement with the pattern of eruptions and deformation observed at Piton de la Fournaise. In contrast with the Hawaiian model of spreading on a décollement, stress permutations in La Réunion's volcanoes imply that the basal deformation of the edifices, if any, is not sufficient to compensate the reduction of deviatoric stress caused by intrusions.

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Eastern Olympus Mons Basal Scarp: Structural and mechanical evidence for large‐scale slope instability

et al. 2014

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The expression of the Eastern Olympus Mons Basal Scarp (EOMBS) is seemingly unique along the edifice. It exhibits two slope-parallel structures: a nearly 100 km long upslope extensional normal fault system and a downslope contractional wrinkle ridge network, a combination that is found nowhere else on Olympus Mons. Through structural mapping and numerical modeling of slope stability of the EOMBS, we show that these structures are consistent with landsliding processes and volcanic spreading. The EOMBS is conditionally stable when the edifice contains pore fluid, and critically stable, or in failure, when the edifice contains a dipping overpressured confined aquifer and mechanical sublayer at depth. Failure of the fault-bounded portion of the flank results in estimated volumes of material ranging from 5600-6900 km 3 , or 32-39% of the estimated volume of the "East" Olympus Mons aureole lobe. We suggest that the EOMBS faults may be an expression of early stage flank collapse and aureole lobe formation. Ages of deformed volcano adjacent plains associated with the wrinkle ridges indicate that this portion of the edifice may have been tectonically active at < 50 Ma and may be coeval with estimated ages of adjacent outflow channels, 25-40 Ma. This observation suggests that conditions that favor flank failure, such as water at depth below the edifice, existed in the relatively recent past and potentially could drive deformation to the present day.

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Overthrusting and sediment accretion along Kilauea's mobile south flank, Hawaii: Evidence for volcanic spreading from marine seismic reflection data

Cited by 100 publications

References 13 publications

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

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

Deformation of basaltic shield volcanoes under cointrusive stress permutations

Eastern Olympus Mons Basal Scarp: Structural and mechanical evidence for large‐scale slope instability

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