Welcome to our blog

Bumi_ino

Hi all! Welcome to our blog, Tektonesiana.

The name of Tektonesiana is derived from the word tectonics and Indonesia. Tektonesiana represents our ‘passion’ on tectonics of Indonesia.

We, Indonesian geologists who share the same interest, use this blog to post articles that represent our works. These articles have been presented in scientific meetings. Some of them also have been published in journals. We have many questions about tectonics of Indonesia, and we want to share them with you. Enjoy our blog!

View our list of publications

Aseismic zone and earthquake segmentation associated with a deep subducted seamount in Sumatra

Singh_seam subd_2011

This article has been published in Nature Geoscience, 2011 . The authors have identified a seamount 3–4 km high and 40 km wide that has been subducted to a depth of 30–40 km below the Sumatra forearc mantle. The seamount has remained intact despite more than 160 km of subduction, and that there is no seismic activity either above or below the seamount. The authors suggest that the subduction of a topographic feature such as a seamount could lead to the segmentation of the subduction zone.

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Neotectonics of the southern Sumatran Forearc

Mukti_2012_neotec ipa

This article notes the structural features in the Mentawai forearc that can be interpreted as products of compression of the accretionary wedge and forearc basin sediments. Compressional phases since the Late Miocene initiated (a) the landward vergent foldthrust belt in the Mentawai Fault Zone (MFZ), (b) reactivation of seaward vergent imbricated thrusts in the retro-accretionary wedge, and (c) uplift of the accretionary wedge and some parts of the forearc basin. The authors interpret that the northwest part of the accretionary wedge underwent higher compression and tilting. The compression of the forearc is suggested to be controlled by the combination of the geometry and position of the continental backstop, and the subducting bathymetric high in the oceanic plate.

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New insight on the deformation along the southern Java forearc

This note is taken from an abstract presented at American Geophysical Union, Fall Meeting 2012. The new seismic data set in south Java resolved detailed structures of the southern Java forearc. The plate interface expressed as irregular surface in the western part and rather a continuous smooth boundary in the eastern area. This observation coincides with the higher uplift of the western part of the forearc high. Cluster of shallow earthquakes can be observed near the western part of Java trench. Deformation of the forearc high is more intense in the west compared to that in the east. This coincides with higher uplift of the western part of the forearc high, thus complicated the structures.

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Seismic images of the megathrust rupture during the 25th October 2010 Pagai earthquake, SW Sumatra: Frontal rupture and large tsunami

Singh_Pagai eq thrust front_grl2011

This is a note from an article that has been published in Geophysical Research Letters, 2011. An earthquake of Mw = 7.8 occurred on the 25th October 2010, SW of Pagai Island, Sumatra. The earthquake generated an unexpected very large tsunami on Pagai Islands with run‐up height of up to 8 m. Here we present seismic reflection and bathymetry images from the 2010 epicentral region acquired before the earthquake. The authors found that the frontal thrust is the main active fault in this region and might have ruptured up to the seafloor at 6 km water depth uplifting the water column and producing a large tsunami.

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