Abstract
Abstract. A very high magnitude earthquake (9.1 MW) triggered a devastating Tsunami in the Indian Ocean on 26th December 2004. The epicentre was located at 3.3° N, 95.8° E with a focal depth of ~30 km. The impacts of Tsunami were felt as far away in Somalia, Tanzania and Kenya along the east coast of Africa. Considering the role of earthquake, in the present study the spatio-temporal analysis of long term (1901 to 2019) earthquake events was performed, which recorded by USGS to understand the genesis of Tsunami (2004) in the Indian Ocean. The study exhibited that the maximum frequency of earthquake was observed between the ranges of 4 MW to 6 MW on the Richter scale during 2001–2010. There was only one earthquake event > 8 MW on the Richter scale (26th December 2004 having depth 30 km) in the Indian Ocean recorded during 1901–2019. The study exhibited that the maximum earthquake was observed between 30–40 km below the surface, and primarily of moderate to low magnitudes. The proximity analysis along the major fault line indicates that the maximum earthquakes were in the buffer of 200 km from fault line in Bay of Bengal. The decadal variation of earthquake exhibits that the maximum number of earthquake events (8427 events) were triggered during the year 2001–2010, whereas during the year 2004, the total 902 earthquake events > 4 MW was recorded. The study indicates that the earthquakes > 7 MW (on Richter scale) and depth below 30 km (shallow earthquake) are primarily responsible to major Tsunami events in the Indian Ocean. The very high magnitude (> 9 MW on the Richter scale) and shallow depth (~30 km) are the major cause of 2004 Tsunami and its high level of damage. There were very low frequency (10–15 events) of earthquake occurred having magnitude > 7 and depth < 30 km.
Highlights
Tsunami, often incorrectly called tidal waves, is a series of waves with a long wavelength and period (Mathur and Udani, 2015)
It takes an earthquake with a Richter magnitude exceeding 7.5 MW to produce a destructive tsunami at specific depth
Since the number of events of earthquakes was increased during the post 1960s, but the magnitude trend was observed decreasing, means earthquake event occurring with less magnitude
Summary
Often incorrectly called tidal waves, is a series of waves with a long wavelength and period (time between crests) (Mathur and Udani, 2015). On 26th December 2004, an earthquake of 9.1 MW occurred at 0:58:53 GMT in Indian Ocean. The epicentre of earthquake was located at 3.3 N, 95.8 E with a focal depth of approximately 30 km (Lavigne et al, 2013), which triggered a massive Tsunami in the coastal areas of Indian Ocean. The vertical offset of the ocean floor by 7 to 10 meters on 26th December 2004, Sumatra earthquake displaced massive volumes of water, resulting in a destructive Tsunami. The wave height in deep water (open ocean) was measured through satellites to be approximately 60 cm, while traveling at a speed of 500 to 800 km/hr. The phenomenon of tsunami is mainly generated undersea disturbance due to earthquake or landslide or activity near the coast or in the ocean and displace few kilometres to >1000 km apart from epicentre. When a disturbance happens the ocean, the ocean floor rise or falls and effects on water above it and as the water moves up and down, seeking to regain its balance, a tsunami is born. (Borrero, 2005; Kanamori and Kikuchi, 1993; Pelayo and Wiens, 1990; Tsuboi, 2000)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
