Structural variability along the submarine south flank of Kilauea volcano, Hawai'i, from a multichannel seismic reflection survey

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

“…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]. The ocean crust reflection, OC, can be distinguished locally 0.2-0.5 s below D (e.g., Figure 3b; SP 400, 5.2 s).…”

“…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.…”

“…The hard seafloor produces strong multiples that can obscure key reflections, particularly in shallow regions. Detailed discussion of various processing techniques used to improve the quality of the seismic data is given by Hills et al [2002] and Leslie et al [2002]. Despite these challenges, the R/V Maurice Ewing seismic data provide surprisingly good images of the substructure of Kilauea's submarine flank, which can be interpreted within the context of seafloor morphology, submersible observations, and on-land geology and geodetics.…”

“…[19] Seismic imaging through volcano flanks is complicated by a variety of factors [e.g., de Voogd et al, 1999;Hills et al, 2002]. In our area, irregular, often chaotic, volcanic deposits commonly show relatively poor reflector coherence and significantly attenuate the seismic signal.…”

“…We employed several techniques to remove strong multiple returns, including prestack and poststack frequency wave number (F-K) filtering, waveform deconvolution, low band-pass filtering to reduce high-frequency multiples, and muting of near-offset multiple returns [e.g., Hills et al, 2002]. We also had good success with radon filtering techniques, wherein multiple returns are modeled and removed in the time intercept, offset domain of common midpoint (CMP) space [Yilmaz, 1987].…”