Current Science

Open Access Open Access  Restricted Access Subscription Access

The 22 June 2020 Mizoram, India earthquake (Mw 5.5): an unusual intra-wedge shallow earthquake in the Indo-Burmese Wedge


Affiliations
1 Department of Geology, Mizoram University, Tanhril, Aizawl 796 004, India
2 Pachhunga University College, Mizoram University, Aizawl 796 001, India
3 Department of Geology, Mizoram University, Tanhril, Aizawl 796 004, India; Central University of Punjab, Bathinda 151 401, India
4 CSIR-National Geophysical Research Institute, Uppal Road, Hyderabad 500 007, India
 

Earthquakes in the Indo-Burmese arc occur due to interaction of India and Sunda plates along the IndoBurmese Wedge and Sagaing Fault. Majority of the moderate to major magnitude earthquakes in the Indo-Burmese Wedge occur within the Indian slab and very few of them occur on the plate interface. Earthquakes within the wedge are rare and the 22 June 2020 earthquake of magnitude 5.5 (Mw) on the India–Myanmar border in Mizoram, India, at shallow depth is probably one such earthquake. The earthquake caused moderate damage (maximum intensity VIII on MSK scale) in remote border villages (Vaphai and Chawngtui) with sparse population without any fatality. The earthquake did not seem to be related with the Mat Fault, which was transverse to the north–south trending wedge, as various estimates of mainshock and the region of maximum damage was ~20 km northeast of the surface trace of the Mat Fault. It appeared to be associated with almost north– south oriented Churachandpur Mao Fault (CMF) with dextral slip which mapped extensively and monitored geodetically in the neighbouring regions of Manipur and Nagaland to the north. Occurrence of this shallow depth earthquake may imply that some segment of the CMF might be seismically active, unlike in the north, where it appears to be predominantly aseismic. This implies that the seismic hazard along the CMF may vary along its length.

Keywords

Churachandpur Mao Fault, earthquakes, Indo-Burmese arc, tectonics.
User
Notifications
Font Size

  • Seeber, L. and Armbruster, J., Great detachment earthquakes along the Himalayan Arc and long-term forecasting. In Earthquake Prediction – An International Review (eds Simpson, D. W. and Richards, P. G.), Maurice Ewing Series. American Geophysical Union, 1981, vol. 4, pp. 259–277.

  • Tiwari, R. P., Status of seismicity in the Northeast India and earthquake disaster mitigation. Envis. Bull. Himalay. Ecol., 2002, 10(1), 10–21.

  • Bilham, R. and England, P., Plateau pop-up in the 1897 Assam earthquake. Nature, 2001, 410, 806–809.

  • Gahalaut, V. K. et al., Aseismic plate boundary in the Indo-Burmese wedge, northwest Sunda Arc. Geology, 2013, 41, 235–238.

  • Steckler, M. S. et al., Locked and loading megathrust linked to active subduction beneath the Indo-Burman Ranges. Nature Geosci., 2016, 9, 615–618.

  • Mallick, R., Lindsey, E. O., Feng, L., Hubbard, J., Banerjee, P. and Hill, E. M., Active convergence of the India–Burma–Sunda plates revealed by a new continuous GPS network. J. Geophys. Res., 2019, 124(3), 3155–3171.

  • Panda, D., Kundu, B., Gahalaut, V. K. and Rangin, C., India–Sunda plate motion, crustal deformation, and seismic hazard in the Indo‐Burmese Arc. Tectonics, 2020, 39; https://doi.org/ 10.1029/2019TC006034.

  • Kundu, B. and Gahalaut, V. K., Earthquake occurrence processes in the Indo-Burmese wedge and Sagaing fault region. Tectonophysics, 2012, 524–525, 135–146.

  • Gahalaut, V. K. et al., Constraints from seismological, geodetic and macroseismic observations on the 4 January 2016 Tamenglong, Manipur earthquake. Tectonophysics, 2016, 688, 36–48.

  • Debbarma, J., Stacey, S., Martin, G., Suresh, A. A. and Gahalaut, V. K., Preliminary observations from the 3 January 2017, Mw 5.6 Manu, Tripura (India) earthquake. J. Asian Earth Sci., 2017, 148, 173–180.

  • Tiwari, R. P., Gahalaut, V. K., Udaya Bhaskara Rao, Ch., Lalasawta, C., Kundu, B. and Malsawmtluanga, No evidence for shallow shear motion on the Mat fault, a prominent strike slip fault in the Indo-Burmese wedge. J. Earth Syst. Sci., 2015, 124, 1039–1046.

  • Maurin, T. and Rangin, C., Structure and kinematics of the IndoBurmese wedge: Recent and fast growth of the outer wedge. Tectonics, 2009, 28, TC2010; https://doi.org/10.1029/2008TC002276.


Abstract Views: 453

PDF Views: 127




  • The 22 June 2020 Mizoram, India earthquake (Mw 5.5): an unusual intra-wedge shallow earthquake in the Indo-Burmese Wedge

Abstract Views: 453  |  PDF Views: 127

Authors

J. Malsawma
Department of Geology, Mizoram University, Tanhril, Aizawl 796 004, India
Paul Lalnuntluanga
Department of Geology, Mizoram University, Tanhril, Aizawl 796 004, India
Saitluanga Sailo
Pachhunga University College, Mizoram University, Aizawl 796 001, India
V. Vanthangliana
Pachhunga University College, Mizoram University, Aizawl 796 001, India
R. P. Tiwari
Department of Geology, Mizoram University, Tanhril, Aizawl 796 004, India; Central University of Punjab, Bathinda 151 401, India
V. K. Gahalaut
CSIR-National Geophysical Research Institute, Uppal Road, Hyderabad 500 007, India

Abstract


Earthquakes in the Indo-Burmese arc occur due to interaction of India and Sunda plates along the IndoBurmese Wedge and Sagaing Fault. Majority of the moderate to major magnitude earthquakes in the Indo-Burmese Wedge occur within the Indian slab and very few of them occur on the plate interface. Earthquakes within the wedge are rare and the 22 June 2020 earthquake of magnitude 5.5 (Mw) on the India–Myanmar border in Mizoram, India, at shallow depth is probably one such earthquake. The earthquake caused moderate damage (maximum intensity VIII on MSK scale) in remote border villages (Vaphai and Chawngtui) with sparse population without any fatality. The earthquake did not seem to be related with the Mat Fault, which was transverse to the north–south trending wedge, as various estimates of mainshock and the region of maximum damage was ~20 km northeast of the surface trace of the Mat Fault. It appeared to be associated with almost north– south oriented Churachandpur Mao Fault (CMF) with dextral slip which mapped extensively and monitored geodetically in the neighbouring regions of Manipur and Nagaland to the north. Occurrence of this shallow depth earthquake may imply that some segment of the CMF might be seismically active, unlike in the north, where it appears to be predominantly aseismic. This implies that the seismic hazard along the CMF may vary along its length.

Keywords


Churachandpur Mao Fault, earthquakes, Indo-Burmese arc, tectonics.

References





DOI: https://doi.org/10.18520/cs%2Fv120%2Fi9%2F1514-1516