Contrasting Décollement and Prism Properties over the Sumatra 2004–2005 Earthquake Rupture Boundary

Dean, S. M.; McNeill, Lisa C.; Henstock, T.; Bull, Jonathan M.; Gulick, Sean P. S.; Austin, James A.; Bangs, N. L.; Djajadihardja, Y.; Permana, Haryadi

doi:10.1126/science.1189373

Cited by 95 publications

(161 citation statements)

References 24 publications

Supporting

Mentioning

157

Contrasting

Order By: Relevance

“…The prominent seismic reflector (seismic Horizon C) that develops negative polarity in proximity to the subduction zone is a primary candidate for décollement development (Dean et al, 2010) and marks the boundary (Unit II/III) between the early pelagic sediment and the rapidly deposited Nicobar Fan. This boundary/transition is characterized by distinct changes in degree of lithification, lithology, physical properties (in particular, magnetic susceptibility), and seismic reflectivity and is potentially associated with diagenetic processes generating fluid (see also Hüpers et al, 2017).…”

Section: Iodp Proceedingsmentioning

confidence: 99%

Sumatra Subduction Zone

McNeill¹,

Dugan²,

Petronotis³

2017

Proceedings of the International Ocean Discovery Program

View full text Add to dashboard Cite

Drilling the input materials of the north Sumatran subduction zone, part of the 5000 km long Sunda subduction zone system and the origin of the Mw ~9.2 earthquake and tsunami that devastated coastal communities around the Indian Ocean in 2004, was designed to groundtruth the material properties causing unexpectedly shallow seismogenic slip and a distinctive forearc prism structure. The intriguing seismogenic behavior and forearc structure are not well explained by existing models or by relationships observed at margins where seismogenic slip typically occurs farther landward. The input materials of the north Sumatran subduction zone are a distinctively thick (as thick as 4-5 km) succession of primarily Bengal-Nicobar Fan-related sediments. The correspondence between the 2004 rupture location and the overlying prism plateau, as well as evidence for a strengthened input section, suggest the input materials are key to driving the distinctive slip behavior and long-term forearc structure. During Expedition 362, two sites on the Indian oceanic plate ~250 km southwest of the subduction zone, Sites U1480 and U1481, were drilled, cored, and logged to a maximum depth of 1500 meters below seafloor. The succession of sediment/rocks that will develop into the plate boundary detachment and will drive growth of the forearc were sampled, and their progressive mechanical, frictional, and hydrogeological property evolution will be analyzed through postcruise experimental and modeling studies. The large penetration depths with good core recovery and successful wireline logging in the challenging submarine fan materials will enable evaluation of the role of thick sedimentary subduction zone input sections in driving shallow slip and amplifying earthquake and tsunami magnitudes at the Sunda subduction zone and globally at other subduction zones where submarine faninfluenced sections are being subducted.

show abstract

Section: Iodp Proceedingsmentioning

confidence: 99%

Sumatra Subduction Zone

McNeill¹,

Dugan²,

Petronotis³

2017

Proceedings of the International Ocean Discovery Program

View full text Add to dashboard Cite

show abstract

“…The unusual rock mechanical properties at the décollement there implied by seismic reflection characteristics may have been responsible for the large 2004 event [140]. Other large earthquakes have been studied with regional geophysical data.…”

Section: (B) Volcanic Islandsmentioning

confidence: 99%

Aspects of marine geoscience: a review and thoughts on potential for observing active processes and progress through collaboration between the ocean sciences

Mitchell

2012

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

Much progress has been made in the UK in characterizing the internal structures of major physiographic features in the oceans and in developing understanding of the geological processes that have created or shaped them. UK researchers have authored articles of high impact in all areas described here. In contrast to terrestrial geoscience, however, there have been few instrumented observations made of active processes by UK scientists. This is an area that could be developed over the next decades in the UK. Research on active processes has the potential ability to engage the wider public: Some active processes present significant geo-hazards to populations and offshore infrastructure that require monitoring and there could be commercial applications of technological developments needed for science. Some of the suggestions could involve studies in shallow coastal waters where ship costs are much reduced, addressing tighter funding constraints over the near term. The possibilities of measuring aspects of volcanic eruptions, flowing lava, turbidity currents and mass movements (landslides) are discussed. A further area of potential development is in greater collaboration between the ocean sciences. For example, it is well known in terrestrial geomorphology that biological agents are important in modulating erosion and the transport of sediments, ultimately affecting the shape of the Earth's surface in various ways. The analogous effect of biology on large-scale geomorphology in the oceans is also known but remains poorly quantified. Physical oceanographic models are becoming increasingly accurate and could be used to study further the patterns of erosion, particle transport and deposition in the oceans. Marine geological and geophysical data could in turn be useful for further verification of such models. Adapting them to conditions of past oceans could address the shorter-period movements, such as due to internal waves and tides, which have been barely addressed in palaeoceanography.

show abstract

“…The sedimentary succession includes lithologic horizons that may develop into the plate boundary décollement for the north Sumatran margin. The primary candidates are (1) a horizon within the deepest sediments overlying oceanic basement (Seismic Horizon C; Figures F6, F7, F8, F9) that develops into a high-amplitude, negative-polarity reflector closer to the trench, which is interpreted as a weak, high-porosity, and probably fluid-rich layer (Dean et al, 2010), and (2) a horizon within the deeper fan sediments (Cook, 2014). In other parts of the margin, such as offshore Central Sumatra , the sediment/basement interface acts as the décollement, and this interface may become important as a detachment surface at greater depth within the subduction zone, including offshore North Sumatra.…”

Section: Scientific Objectivesmentioning

confidence: 99%

Untitled

2017

International Ocean Discovery Program Preliminary Report

View full text Add to dashboard Cite

Drilling the input materials of the north Sumatran subduction zone, part of the 5000 km long Sunda subduction zone system and the origin of the Mw ~9.2 earthquake and tsunami that devastated coastal communities around the Indian Ocean in 2004, was designed to groundtruth the material properties causing unexpectedly shallow seismogenic slip and a distinctive forearc prism structure. The intriguing seismogenic behavior and forearc structure are not well explained by existing models or by relationships observed at margins where seismogenic slip typically occurs farther landward. The input materials of the north Sumatran subduction zone are a distinctively thick (as thick as 4-5 km) succession of primarily Bengal-Nicobar Fan-related sediments. The correspondence between the 2004 rupture location and the overlying prism plateau, as well as evidence for a strengthened input section, suggest the input materials are key to driving the distinctive slip behavior and long-term forearc structure. During Expedition 362, two sites on the Indian oceanic plate ~250 km southwest of the subduction zone, Sites U1480 and U1481, were drilled, cored, and logged to a maximum depth of 1500 meters below seafloor. The succession of sediment/rocks that will develop into the plate boundary detachment and will drive growth of the forearc were sampled, and their progressive mechanical, frictional, and hydrogeological property evolution will be analyzed through postcruise experimental and modeling studies. Large penetration depths with good core recovery and successful wireline logging in the challenging submarine fan materials will enable evaluation of the role of thick sedimentary subduction zone input sections in driving shallow slip and amplifying earthquake and tsunami magnitudes, at the Sunda subduction zone and globally at other subduction zones where submarine faninfluenced sections are being subducted.

show abstract

Contrasting Décollement and Prism Properties over the Sumatra 2004–2005 Earthquake Rupture Boundary

Cited by 95 publications

References 24 publications

Sumatra Subduction Zone

Sumatra Subduction Zone

Aspects of marine geoscience: a review and thoughts on potential for observing active processes and progress through collaboration between the ocean sciences

Untitled

Contact Info

Product

Resources

About