The 2005 volcano‐tectonic earthquake swarm in the Andaman Sea: Triggered by the 2004 great Sumatra‐Andaman earthquake

Kundu, Bhaskar; Legrand, D.; Gahalaut, Vineet K.; Mahesh, P.; Raju, K. A. Kamesh; Catherine, J. K.; Ambikapthy, A.; Chadha, R. K.

doi:10.1029/2012tc003138

Cited by 51 publications

(20 citation statements)

References 76 publications

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“…On the other hand, Kundu et al . [] and Kamesh Raju et al . [] suggest that the volcanism and strike‐slip faults are linked, and the 2005 swarm was due to stress induced by the 2004 earthquake.…”

Section: Seismic Resultsmentioning

confidence: 99%

“…The volcanic melt seems to have been produced by melting at depth (60-80 km) and passed through the mantle and crust without affecting the rheology, and therefore, the volcanoes must be very superficial features along the volcanic arc. On the other hand, Kundu et al [2012] and Kamesh Raju et al [2012] suggest that the volcanism and strike-slip faults are linked, and the 2005 swarm was due to stress induced by the 2004 earthquake.…”

Section: Profile Pgs08-06mentioning

confidence: 99%

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Seismic images of the sliver strike‐slip fault and back thrust in the Andaman‐Nicobar region

Singh

Moeremans

McArdle³

et al. 2013

JGR Solid Earth

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The sliver strike‐slip Great Sumatra Fault (GSF) traverses mainland Sumatra from the Sunda Strait in the southeast to Banda Aceh in the northwest, and defines the present day plate boundary between the Sunda Plate in the north and the Burmese Sliver Plate in the south. It has been well studied on mainland Sumatra but poorly north of Banda Aceh in the Andaman Sea. Here we present deep seismic reflection images along the northward extension of the GSF over 700 km until it joins the Andaman Sea Spreading Centre, and we interpret these images in the light of earthquake, gravity, and bathymetry data. We find that the GSF has two strands between Banda Aceh and Nicobar Island: a transpression in the south and a deep narrow active rift system in the north, dotted with volcanoes in the center, suggesting that the volcanic arc is coincident with rifting. Farther north of Nicobar Island, an active strike‐slip fault, the Andaman‐Nicobar Fault, cuts through a rifted deep basin until its intersection with the Andaman Sea Spreading Centre. The volcanic arc lies just east of the rift basin. The western margin of this basin seems to be a rifted continental margin, tilted westward, and flooring the Andaman‐Nicobar fore‐arc basin. The Andaman‐Nicobar fore‐arc basin is bounded in the west by back thrusts similar to the West Andaman and Mentawai faults. The cluster of seismicity after the 2004 great Andaman‐Sumatra earthquake just north of Nicobar Island coincides with the intersection of two strike‐slip fault systems.

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Section: Seismic Resultsmentioning

confidence: 99%

Section: Profile Pgs08-06mentioning

confidence: 99%

Seismic images of the sliver strike‐slip fault and back thrust in the Andaman‐Nicobar region

Singh

Moeremans

McArdle³

et al. 2013

JGR Solid Earth

View full text Add to dashboard Cite

show abstract

“…This WNW-ESE extension direction, perpendicular to the convergence vector (Figure 12A), is suggested by the collected structural field data in the central and southern part of the GSF (Figures 9, 10) and is also supported by structural and geophysical studies (Lassal et al, 1989;Harjono et al, 1991;Pramumijoyo and Sébrier, 1991;Mount and Suppe, 1992;Kundu et al, 2012;Muksin et al, 2014). The ∼WNW-ESE extension direction may explain the common ∼NNE-SSW elongation and/or alignment of many volcanoes (Figure 8).…”

Section: Discussionmentioning

confidence: 55%

“…The 2004 mega-earthquake was followed, 1 month later, by a seismic swarm in the Andaman Sea north of Sumatra (Kundu et al, 2012) and volcanism, as testified by a submarine eruption . In particular, this seismicity is at first consistent with the regional tectonic setting and, subsequently, with the involvement of fluids, also magmatic, producing normal faults along a NNE-SSW direction (Kundu et al, 2012).…”

Section: Tectonic Setting Of Sumatramentioning

confidence: 99%

Weak Tectono-Magmatic Relationships along an Obliquely Convergent Plate Boundary: Sumatra, Indonesia

et al. 2018

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The tectono-magmatic relationships along obliquely convergent plate boundaries, where strain partitioning promotes strike-slip structures along the volcanic arc, are poorly known. Here it is unclear if and, in case, how the strike-slip structures control volcanic processes, distribution and size. To better define the possible tectono-magmatic relationships along strike-slip arcs, we merge available information on the case study of Sumatra (Indonesia) with field structural data. The Sumatra arc (entire volcanic belt) consists of 48 active volcanoes. Of these, 46% lie within 10 km from the dextral Great Sumatra Fault (GSF), which carries most horizontal displacement on the overriding plate, whereas 27% lie at >20 km from the GSF. Among the volcanoes at <10 km from GSF, 48% show a possible structural relation to the GSF, whereas only 28% show a clear structural relation, lying in pull-aparts or releasing bends; these localized areas of transtension (local extensional zone) do not develop magmatic segments. There is no relation between the GSF along-strike slip rate variations and the volcanic productivity. The preferred N30 • -N40 • E volcano alignment and elongation are subparallel to the convergence vector or to the GSF. The structural field data, collected in the central and southern GSF, show, in addition to the dextral motions along NW-SE to N-S striking faults, also normal motions (extending WNW-ESE or NE-SW), suggesting local reactivations of the GSF. Overall, the collected data suggest a limited tectonic control on arc volcanism. The tectonic control is mostly expressed by the mean depth of the slab surface below the volcanoes (130 ± 20 km) and, subordinately, local extension along the GSF. The latter, when WNW-ESE oriented (more common), may be associated with the overall tectonic convergence, as suggested by the structural data; conversely, when NE-SW oriented (less common), the extension may result from co-and post-seismic arc normal extension, as supported by the 2004 mega-earthquake measurements. Overall, the strike-slip arc of Sumatra has intermediate features between those of extensional and contractional arcs.

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“…Kamesh Raju et al () showed that the swarm localized on a dormant seamount and documented evidence for former hydrothermal activity and manganese nodules. Mukhopadhyay and Dasgupta () and Mukhopadhyay et al () argued that the swarm demonstrated a complex faulting series with “initially ... strike‐slip motion followed by normal faulting in repetitive sequences, whose representative fault planes orient at high angle to the regional faults.” These authors suggest a nascent rift segment forming in a ~NW‐SE trending direction and discuss a “pressure front from ascending magmatic fluid.” Kundu et al () continue this discussion.…”

Section: Decomposition Of a Complex Scatterplotmentioning

confidence: 99%

Structural Geology and the Seismotectonics of the 2004 Great Sumatran Earthquake

et al. 2018

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The paper sets out a method for structural analysis of seismotectonic data using centroid moment tensors and associated hypocenters from the Global Centroid Moment Tensor project, here illustrated for aftershocks from the 2004 great Sumatran earthquake. We show that the Sumatran segments of the megathrust were subject to compression in a direction near to orthogonal with the margin trend, consistent with the effect of relative movement of the adjacent tectonic plates. In contrast, the crust above the Andaman Sea segments was subject to margin‐orthogonal extension, consistent with motion toward the gravitational potential well accumulated due to prior lateral (westward) rollback of the subducting edge of the northward moving Indian plate. Since this potential well is largely defined by topography, this episode of margin‐orthogonal extension is at least in part “gravity driven.” It did not last long. Within 15 months, an earthquake cluster across an Andaman Sea spreading segment showed a return to kinematics driven by relative plate motion. The transition can be explained if fluid activity temporarily reduced basal friction (or effective stress) but then led to healing so that the megathrust once again began to develop friction‐locked segments. The influence of slab rollback is in developing a gravitational potential well facing the megathrust, hence drawing the overriding crust toward it in the immediate postrupture phase while the megathrust is in a weakened state. Plate tectonics dominates during interseismic gaps, once the megathrust heals, and regains frictional resistance.

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The 2005 volcano‐tectonic earthquake swarm in the Andaman Sea: Triggered by the 2004 great Sumatra‐Andaman earthquake

Cited by 51 publications

References 76 publications

Seismic images of the sliver strike‐slip fault and back thrust in the Andaman‐Nicobar region

Seismic images of the sliver strike‐slip fault and back thrust in the Andaman‐Nicobar region

Weak Tectono-Magmatic Relationships along an Obliquely Convergent Plate Boundary: Sumatra, Indonesia

Structural Geology and the Seismotectonics of the 2004 Great Sumatran Earthquake

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