Current Science

Open Access Open Access  Restricted Access Subscription Access

An Appraisal of Recent Earthquake Activity in Palghar Region, Maharashtra, India


Affiliations
1 CSIR-National Geophysical Research Institute, Hyderabad 500 007, India
 

The present study focuses on the recent earthquake activity in Palghar region, Maharashtra, India. Until 31 August 2019, a total of 4854 earthquakes have been located here, whose local magnitude (ML) varied from 0.1 to 4.1. Majority of the earthquakes (~94%) were located in the depth range 4–16 km. The precise earthquake relocations reveal two clusters. The N–S trending cluster north of 20.04°N extends to a depth of 10 km, whereas the NE–SW trending cluster to the south of 20.04°N extends to 16 km depth. The shallow northern cluster is noticed to be sandwiched between two mapped mafic intrusions, whereas the deeper southern segment shows earthquakes clustering around the mafic intrusion. The modelled composite focal mechanism solutions for both the north and south clusters suggest normal faulting with a minor strike–slip component as the dominant deformation mode for the Palghar region. From relocated seismici-ty, we have detected a deeper seismically active zone (with M> 3) at 4–16 km depth, occupying a crustal volume of 1440 km 3 (i.e. 20 km (in N–S) ×6 km (in E– W) and 12 km (in depth)) that dips toward 20°S and 70°W. This could be attributed to the large crustal stresses induced by the mafic intrusive body below the region.

Keywords

Crustal Stress, Deformation Mode, Earth-quake, Mafic Intrusion, Relocations, Seismic Activity.
User
Notifications
Font Size

  • Reeves, C. V. and de Wit, M., Making ends meet in Gondwana: retracing the transforms of the Indian Ocean and reconnecting continental shear zones. Terra Nova, 2002, 12(6), 272–280.

  • Courtillot, V. E., Besse, J., Vandamme, D., Montigny, R., Jaeger, J. and Cappetta, H., Deccan flood basalts at the Cretaceous/ Tertiary boundary? Earth Planet. Sci. Lett., 1986, 80, 361–374.

  • Deshpande, G. G. and Pitale, U. L., Geology of Maharashtra, Geological Society of India, 2014, pp. 1–265.

  • Kissling, E., Geotomography with local earthquake data. Rev. Geophys., 1988, 26, 659–698.

  • Chatelain, J. L., Roecker, S. W., Hatzfeld, D. and Molnar, P., Microearthquake seismicity and fault plane solutions in the Hindu Kush region and their tectonic implications. J. Geophys. Res., 1980, 85, 1365–1387.

  • Gomberg, J. S., Shedlock, K. M. and Roecker, S. W., The effect of S-wave arrival times on the accuracy of hypocenter estimation. Bull. Seismol. Soc. Am., 1990, 80, 1605–1628.

  • Dasgupta, S. et al., Seismotectonic Atlas of India and its Environs, Geological Survey of India, 2000.

  • Ottemoller, L., Voss, P. and Havskov, J., Seisan Earthquake Analysis Software, Version 11, 2018.

  • Kaila, K. L., Murthy, P. R. K., Rao, V. K. and Kharetchko, G. E., Crustal structure from deep seismic sounding along the Koyna II (Kelsi–Loni) profile in the Deccan Trap area, India. Tectonophys, 1981, 73, 365–384.

  • Kaila, K. L., Reddy, P. R., Dixit, M. M. and Lazarenko, M. A., Deep crustal structure at Koyna, Maharashtra, indicated by deep seismic sounding. J. Geol. Soc. India, 1981, 22, 1–16.

  • Kissling, E., Velest User’s Guide. Internal report, Institute of Geophysics, ETH Zürich, Switzerland, 1995, p. 26.

  • Wiemer, S., A software package to analyze seismicity: ZMAP. Seismol. Res. Lett., 2001, 72(3), 373–382.


Abstract Views: 276

PDF Views: 77




  • An Appraisal of Recent Earthquake Activity in Palghar Region, Maharashtra, India

Abstract Views: 276  |  PDF Views: 77

Authors

D. Srinagesh
CSIR-National Geophysical Research Institute, Hyderabad 500 007, India
Dhiraj Kumar Singh
CSIR-National Geophysical Research Institute, Hyderabad 500 007, India
G. Vikas
CSIR-National Geophysical Research Institute, Hyderabad 500 007, India
B. Naresh
CSIR-National Geophysical Research Institute, Hyderabad 500 007, India
Sunil Roy
CSIR-National Geophysical Research Institute, Hyderabad 500 007, India
Y. V. V. B. S. N. Murthy
CSIR-National Geophysical Research Institute, Hyderabad 500 007, India
P. Solomon Raju
CSIR-National Geophysical Research Institute, Hyderabad 500 007, India
G. Suresh
CSIR-National Geophysical Research Institute, Hyderabad 500 007, India
Prantik Mandal
CSIR-National Geophysical Research Institute, Hyderabad 500 007, India
A. N. S. Sharma
CSIR-National Geophysical Research Institute, Hyderabad 500 007, India
M. Shekar
CSIR-National Geophysical Research Institute, Hyderabad 500 007, India
V. M. Tiwari
CSIR-National Geophysical Research Institute, Hyderabad 500 007, India

Abstract


The present study focuses on the recent earthquake activity in Palghar region, Maharashtra, India. Until 31 August 2019, a total of 4854 earthquakes have been located here, whose local magnitude (ML) varied from 0.1 to 4.1. Majority of the earthquakes (~94%) were located in the depth range 4–16 km. The precise earthquake relocations reveal two clusters. The N–S trending cluster north of 20.04°N extends to a depth of 10 km, whereas the NE–SW trending cluster to the south of 20.04°N extends to 16 km depth. The shallow northern cluster is noticed to be sandwiched between two mapped mafic intrusions, whereas the deeper southern segment shows earthquakes clustering around the mafic intrusion. The modelled composite focal mechanism solutions for both the north and south clusters suggest normal faulting with a minor strike–slip component as the dominant deformation mode for the Palghar region. From relocated seismici-ty, we have detected a deeper seismically active zone (with M> 3) at 4–16 km depth, occupying a crustal volume of 1440 km 3 (i.e. 20 km (in N–S) ×6 km (in E– W) and 12 km (in depth)) that dips toward 20°S and 70°W. This could be attributed to the large crustal stresses induced by the mafic intrusive body below the region.

Keywords


Crustal Stress, Deformation Mode, Earth-quake, Mafic Intrusion, Relocations, Seismic Activity.

References





DOI: https://doi.org/10.18520/cs%2Fv118%2Fi10%2F1592-1598