Earthquakes in Arunachal Pradesh, India

Capital - Kabul
Population - 1,091,117 (2001)

Population per district (Top 5)
Lohit - pop. 143,527
Changlang - pop. 124,422
Papum Pare - pop. 122,023
West Siang - pop. 103,918
Tirap - pop. 100,326

Earthquake History
Arunachal Pradesh is the cordon sanitaire between the Indian and the Eurasian plates in North-eastern India. Dozens of earthquakes are recorded in this region every year. The earthquake activity in this region is due to the Indian plate diving (thrusting) beneath the Eurasian plate. This process can trigger powerful earthquakes. Earthquakes here are generally shallow but in the Naga Hills some intermediate focus events have also occurred.

Seismic Hazard

All districts of the state of Arunachal Pradesh lie in Zone V. Since the earthquake database in India is still incomplete, especially with regards to earthquakes prior to the historical period (before 1800 A.D.), these zones offer a rough guide of the earthquake hazard in any particular region and need to be regularly updated (See also: GSHAP Hazard Map for Arunachal Pradesh).
 

Largest Instrumented Earthquake in Arunachal Pradesh
15 August 1950 - Indo-China Border Region, Mw 8.6
19:39:28.5 IST/ 14:09:28.5 UTC, 28.70N 96.60E
This "Independence Day" earthquake was the 6th largest earthquake of the 20th century. Though it hit in a mountainous region along India's international border with China, 1500 people were killed and the drainage of the region was greatly affected. The resultant floods were the cause of most of the fatalities blamed on this earthquake. The initial shock was followed by thousands of aftershocks, some of which were big earthquakes in their own rights.

Significant Earthquakes in Arunachal Pradesh
The following list briefly outlines known earthquakes in this region. General locations are provided for historical events for which "generalized" epicentral co-ordinates are available. Some events which were significant for other reasons are also included. This list will be updated whenever newer information is available. Please note that Magnitude and Intensity are NOT THE SAME. All events are within the state or union territory covered on this page unless stated otherwise.

Acronyms Used:
D=Depth, OT=Origin Time, Mw=Moment Magnitude, Ms=Surface Wave magnitude, Mb=Body Wave Magnitude, ML=Local Magnitude, M?=Magnitude Type unknown

17 February 1905 - Xizang, China, North of the border with India, Mw 7.1 (Ambraseys '00)
11:42 UTC, 30.00 N, 95.00 E

12 May 1906 - Indo-China Border, North of Itanagar, India, Mw 6.5 (Ambraseys '00)
05:50 UTC, 28.00 N, 92.00 E

31 August 1906 - Indo-Myanmar Border, Near Chaukan Pass, India, Ms 7.0
14:57:30.0 UTC, 27.00 N, 97.00 E

12 December 1908 - Northern Sagaing Division, Myanmar, Ms 7.6
12:54:54.0 UTC, 26.50 N, 97.00 E
South of the Chaukan Pass, India

27 January 1941 - Indo-Bhutan Border region, Ms 6.7
12:41:48.0 UTC, 27.00 N, 92.00 E

29 July 1947 - Indo-China Border north of Itanagar, Mw 7.3, Ms 7.5
13:29:25.0 UTC, 28.50 N, 94.00 E

15 August 1950 - Indo-China Border Region, Mw 8.6
19:39:28.5 IST/ 14:09:28.5 UTC, 28.70N 96.60E
This "Independence Day" earthquake was the 6th largest earthquake of the 20th century. Though it hit in a mountainous region along India's international border with China, 1500 people were killed and the drainage of the region was greatly affected. The resultant floods were the cause of most of the fatalities blamed on this earthquake. The initial shock was followed by thousands of aftershocks, some of which were big earthquakes in their own rights.

15 August 1950 - Patkoi hills, Tirap District, Arunachal Pradesh (Indo-Myanmar Bdr), 8.0 (TS)
21:42:16 UTC, 25.00 N, 95.80 E

16 August 1950 - North of Sadiya, Dihang Valley District (Arunachal Pradesh), 7.0 (TS)
06:41:59.5 UTC, 28.60 N, 95.70 E

13 September 1950 - NW of Sadiya, Dihang Valley District (Arunachal -Assam Bdr), 7.0 (TS)
11:07:34.1 UTC, 27.80 N, 94.30 E

12 March 1951 - Indo-China Border north of Itanagar, Ms 6.5
14:52:20.0 UTC, 28.70 N, 94.20 E

18 November 1951 - North of Dibrugarh, West Siang District (Arunachal Pradesh), 6.7 (TS)
00:44:10 UTC, 27.70 N, 94.60 E

20 February 1962 - Myanmar, South-east of the Patkoi hills, India, Ms 6.7
22:02:35.0 UTC, 26.13 N, 96.94 E

7 June 2000 - Northern Sagaing Division, Myanmar, Mw 6.4, Ms 6.5, Mb 6.3 (NEIC)
21:46:55 UTC, 26.856 N, 97.238 E
South the Chaukan Pass, India.

18 August 2003 - Upper Tsangpo, Xizang, Mw 5.5
29.547 N, 95.562 E, D=29 kms, OT=09:03:02 UTC
A moderate earthquake struck the Upper Tsangpo Valley in eastern Tibet, close to the border with India, on 18 August 2003 at 17:03 PM local time. It had a magnitude of Mw=5.5 and was felt in parts of Nyingchi prefecture causing minor damage.

1 June 2005 - Upper Dibang Valley, Arunachal Pradesh, Mw 5.7
28.871 N, 94.598 E, D=18 kms, OT=04:16:48 UTC
A moderate earthquake struck the Upper Dibang Valley in Arunachal Pradesh, India, on 2 June 2005 at 01:36 AM local time causing minor landsides. The earthquake had a magnitude of Mw=5.7.