Intensities of M 6.8 Earthquake of SIKKIM, INDIA 2011 September 18

vulnerability of Structures

Overall, the population in this region resides in structures that are highly vulnerable to earthquake shaking, though some resistant structures exist. The predominant vulnerable building types are unreinforced brick masonry and rubble/field stone masonry construction.

Intensities of the Significant Cities on Modified Mercalli Intensity Scale (MMI)

MMI	City	Population
VI	Mangan	1k*
VI	Singtam	6k
VI	Namchi	1k
VI	Gangtok	31k
VI	Naya Bazar	1k
V	Rangpo	4k
V	Shiliguri	516k
IV	Thimphu	99k
III	Kathmandu	1,442k
III	Bhagalpur	362k
III	Patna	1,600k

* K= X 1000

Seismic details are:

2011 September 18 12:40:48 UTC : SIKKIM, INDIA 

Magnitude: 6.8

Date-Time : Sunday, September 18, 2011 at 12:40:48 UTC

Sunday, September 18, 2011 at 06:10:48PM at epicenter
Location : 27.730°N, 88.082°E

Depth : 20.7 km (12.9 miles)

Region : SIKKIM, INDIA

Distances: 69 km (43 miles) NW (310°) from Gangtok, Sikkim, India

120 km (74 miles) NNW (343°) from Shiliguri, West Bengal, India

 272 km (169 miles) E of KATHMANDU, Nepal

572 km (355 miles) N of Kolkata (Calcutta), West Bengal, India

Subduction Zones-Purple, Ridges-Red and Transform Faults Green

Location Uncertainty :  horizontal +/- 14.4 km (8.9 miles); depth +/- 7.4 km (4.6 miles)

Parameters : NST=258, Nph=258, Dmin=369.6 km, Rmss=1.17 sec, Gp= 29°, M-type=regional moment magnitude (Mw), Version=9