Rising Seismic Activity Highlights Almora Fault Activation in Western Nepal
Recent data reveals a surge in earthquake occurrences throughout 2023, primarily linked to the activation of the Almora fault in Western Nepal. This activation triggered significant mainshock earthquakes on January 24, 2023 (Magnitude: 5.8), October 3, 2023 (Magnitude: 6.2), and November 3, 2023 (Magnitude: 6.4). These mainshocks, accompanied by subsequent aftershocks, have contributed to an elevated frequency of earthquakes in the region during the year.
While fluctuations in seismic activity are common for northern India and Nepal, the recent increase is noteworthy. Nepal and the adjoining northern part of India, located near the active faults of the Himalayan region, are highly seismically active areas prone to frequent earthquakes due to collision tectonics, where the Indian plate subducts beneath the Eurasian Plate.
Details of earthquake occurrences (Magnitude 3.0 and above) in these regions, as recorded by the National Center for Seismology, New Delhi, over the last three years and the current year are as follows:
| Earthquake Magnitude Range | Number of Earthquakes (2020) | Number of Earthquakes (2021) | Number of Earthquakes (2022) | January to Nov. 2023 |
|---|---|---|---|---|
| 3.0 to 3.9 | 42 | 41 | 41 | 97 |
| 4.0 to 4.9 | 18 | 18 | 20 | 21 |
| 5.0 to 5.9 | 1 | 1 | 3 | 4 |
| 6.0 to 6.9 | 0 | 0 | 1 | 2 |
The Bureau of Indian Standards (BIS) has issued the Seismic Zoning Map of India, categorizing regions from Zone II to V, providing guidelines for implementing essential engineering codes and practices to construct earthquake-resistant buildings. The National Disaster Management Authority (NDMA) plays a crucial role in implementing precautionary measures such as earthquake drills, awareness programs, and earthquake management to enhance preparedness and response to earthquake-related incidents.
This information was presented by the Union Minister of Earth Sciences, Kiren Rijiju, in a written reply in the Lok Sabha.
