Morphology of the subducted Indian plate in the Indo-Burmese convergence zone

S., S.; Srinagesh, D.; Sarma, P. V. S. S. Rajagopala

doi:10.1007/bf02842315

Cited by 10 publications

(2 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Dibru‐Saikhoa island is situated in an intermontane valley representing the foreland part of both the Eastern Himalayas (Acharyya et al, 1983) and the Naga‐Patkai Mountains (Acharyya, 1986; Verma et al, 1976). These later‐mentioned hills are sometimes treated as part of the Burmese arc (Johnson, 2002; Rai et al, 1996) containing several overthrust sheets. The Himalayan range results from the Indian and Eurasian plate collision dating back to the Eocene (Butler & Coward, 1989; Dewey & Bird, 1970; Dewey et al, 1989; Searle & Treloar, 2019; Yin, 2006).…”

Section: The Tectono‐geomorphic Setting Of Dibru‐saikhoa Islandmentioning

confidence: 99%

Morphotectonic forcing and anthropogenic impact behind a recently emerged relict island of the Brahmaputra River

Gogoi

Chetia

Borgohain

et al. 2022

Earth Surf Processes Landf

View full text Add to dashboard Cite

Large rivers can be significantly impacted upon by both tectonics and human activities; yet, there are very few studies where these natural and anthropogenic impacts combine. A new river island called Dibru-Saikhoa has appeared very recently on the Brahmaputra valley map in Assam. More than 200 km 2 in area, it is situated in the extreme upstream reach of the Brahmaputra River and represents the second biggest relict island after Majuli (with a present area of $500 km 2 ). The cause of the formation of this island is generally attributed to river dynamics, with only a minor anthropogenic role. However, our study, considering morphological changes from 1915 to 2019 and subsurface geophysical data, suggests that the anthropogenic factor was an important 'trigger' of island formation, acting on a system made sensitive to change by the combination of local tectonics and rapidly changing sediment influx.Making use of the satellite-borne Bouguer gravity data and ground survey-based seismic sections, we located some of the prominent blind faults. Taking into consideration recent activation and interplay of these faults, the mode of accommodation space generation, and aggradation characteristics due to fluvial processes, we suggest a multi-order mechanism of formation of this relict island. The first-order trigger is due to the unstable river morphology of the Siang, which is responding to tilting of the valley floor as a co-seismic phenomenon, and subsequently influences two other rivers-the Dibang and the Lohit. Second-order forcing comes from intra-plate residual pop-up that comes into play due to uneven sediment loading. The third-order forcing is inter-plate suturing, which causes arching and fracturing of the basement.

show abstract

Section: The Tectono‐geomorphic Setting Of Dibru‐saikhoa Islandmentioning

confidence: 99%

Morphotectonic forcing and anthropogenic impact behind a recently emerged relict island of the Brahmaputra River

Gogoi

Chetia

Borgohain

et al. 2022

Earth Surf Processes Landf

View full text Add to dashboard Cite

show abstract

“…The Indian Plate is also subducting below the Burmese Plate towards the east (Curray, 1989; Khogenkumar et al, 2021; Li, van der Hilst, Meltzer, & Engdahl, 2008; Mitchell & Mckerrow, 1975). Based on the study of seismicity and tomography the subducted Indian lithosphere can be seen up to a depth of ~200 km (Hurukawa, Tun, & Shibazaki, 2012; Rai, Srinagesh, & Rajagopala Sarma, 1996; Raoof, Mukhopadhyay, Koulakov, & Kayal, 2017). Based on fault plane solutions Chen and Molnar (1990), Le Dain, Tapponnier, and Molnar (1984), and Ni et al (1989) opined that subduction has stopped and at present, the subducted slab is being dragged northward along the movement of the India Plate.…”

Section: Introductionmentioning

confidence: 99%

Along‐strike variation in the shear wave crustal structure of the NE Himalayan and Indo‐Burmese arc: Evidence based on surface wave dispersion analysis

Chanu

Kumar

Kumar³

et al. 2022

Geological Journal

View full text Add to dashboard Cite

Surface wave dispersion data is used to infer the shear wave velocity structure variation in the north‐east Himalaya and Indo‐Burmese arc regions. We have used 25 earthquakes data from four groups with a magnitude range of 5.0–6.7, epicentral distance range 368–800 km, and focal depth less than 50 km. Ray paths from the earthquake location to the seismic station are transversely passing different geotectonic units of the Himalayas, Indo‐Gangetic plains, and Indo‐Burma collision zones. The weighted average dispersion curve and the path averaged shear wave velocity models are computed for the four groups located at different azimuths around Shillong seismic station. Non‐linear least‐square inversion is performed to obtain the shear wave velocity structure of the crust and uppermost mantle from joint inversion of Rayleigh and Love waves group velocities. Subsequently, Rayleigh and Love waves group velocities are inverted separately to obtain vertical and horizontal components of S‐wave velocity. Next, using these components anisotropy coefficient values at different depths for each path are also estimated. A high variation of dispersion curves and the shear wave velocity models from one group to another indicates that the region is geotectonically very complex. An approximately 80 km‐thick zone beneath the study region has shear wave velocity as low as 1.7 km/s in the uppermost crust in the southern part and ~4.7 km in the uppermost mantle beneath the Eastern Himalayan Syntaxis (EHS). Inferred velocity is also lower than that of PREM and AK135 global models with a much thicker crust beneath the study region. Radial anisotropy varies even within the northern part from the Indo‐Eurasian collision zone to EHS and northern to southern Indo‐Burma ranges. Anisotropy is comparatively stronger in the deeper part below ~40 km for the three paths, except for the EHS, where the result is contrary.

show abstract

Oblique Plate Convergence in the Indo-Burma (Myanmar) Subduction Region

Satyabala¹

2003

Pure appl. geophys.

View full text Add to dashboard Cite

Morphology of the subducted Indian plate in the Indo-Burmese convergence zone

Cited by 10 publications

References 20 publications

Morphotectonic forcing and anthropogenic impact behind a recently emerged relict island of the Brahmaputra River

Morphotectonic forcing and anthropogenic impact behind a recently emerged relict island of the Brahmaputra River

Along‐strike variation in the shear wave crustal structure of the NE Himalayan and Indo‐Burmese arc: Evidence based on surface wave dispersion analysis

Oblique Plate Convergence in the Indo-Burma (Myanmar) Subduction Region

Contact Info

Product

Resources

About