26
Mar
11

Myanmar earthquake

The Myanmar earthquake of magnitude 6.8 (USGS) that occurred near Kengtung, on 24 March 2011 at 13.55 UTC (7.25 pm IST), was a major earthquake of recent times in this region. The depth of focus reported was 10 km. According to the Chinese seismological observatory, the magnitude of the earthquake was 7.0 with the focus located at a depth of 20 km. The epicenter is located within Myanmar near the boundary of the three countries- Thailand, Vietnam and Myanmar.

 

The Seimological office in Myanmar recorded more than 6 after shocks of M5.0 and over 60 aftershocks of M<5. A major threat was to Srinagarind dam located in Thailand boardering Myanmar. However the dam was not affected.

 The earthquake resulted due to left-strike-slip movement of the Indian and Sunda plate along the Sagaing fault, a major N-S fault with a slip rate of 18mm/y. The Sagaing fault is a very active fault that hosted several earthquakes in the past including the 6.9 magnitude earthquake of February 1991.  The movement of the Indan plate with respect to the Sunda plate is about 45mm/y. The Sagaing faults continues south and transform into a series of transform faults in the Andaman Ses, east of the Narcondam and Barrend island volcanoes and joins ultimately the Sumatra fault. It is interesting to note that this fault was a loci of five major volcanic activity. Extint volcanic cones lies along the fault.

 Kengtung city was worst affected and a hospital in Tarlay was damaged. Over all deaths reported was 65 and 111 were injured.  390 houses were damaged, 14 monasteries and 9 gov. buildings were destroyed. 

The Chinese border (Yunan province) lies about 80 km from the epicenter. According to a local report from China and Myanmar, nearly 6500 people were affected in Yunan provinces by this earthquake.