Seismologist calls for more monitoring stations to track quake risks in NE India

Guwahati, Oct 22: Northeast India, a high seismic zone and site of some of the most destructive earthquakes in history, requires more seismic monitoring stations for better analysis of earthquake hazards, according to seismologist Prof Alan L Kafka, Earth and Environmental Sciences faculty and former Director of Weston Observatory (Boston College’s Geophysical Research and Science Education Center).

Having studied earthquakes around the world, Prof Kafka’s team has installed a seismograph at Madhabdev University, North Lakhimpur. He spoke to The Assam Tribune on the seismic scenario of the region. The excerpts:

AT: Northeast India lies in a high seismic zone. What are your observations regarding the recent quakes and future probabilities?

Prof Alan: I am used to working mostly in regions of much lower earthquake activity than Northeast India, particularly the Northeastern US (NEUS), which is an “intraplate” region, i.e., a region far away from major plate boundary activity. So, in our work on Northeast India earthquakes, it is a new experience for me to be dealing with such a high-level of activity associated with the India plate/Eurasian plate boundary. In this regard, Northeast India is the site of one of the most destructive and tragic earthquakes in history – the 1950 earthquake of 8.6 magnitude that occurred in the border region between Assam and Tibet. The Northeast India also experienced an earthquake of 8.1 magnitude in 1897 that occurred in the Shillong Plateau, and caused massive destruction across the region. In addition, in 1869, there was an earthquake of 7.4 magnitude in Cachar, Assam, and since that earthquake, the region has experienced about 25 major earthquakes with magnitudes exceeding 7.0. These major earthquakes, along with the continuing intense seismic activities, underscore the critical importance of understanding and, ideally, mitigating earthquake hazards in this region.

On September 14, 2025, an earthquake of 5.8 magnitude near Guwahati was recorded by our new seismograph at Madhabdev University, North Lakhimpur. The official United States Geological Survey (USGS) location of this earthquake didn’t include any nearby stations to enable an accurate location. But I was able to get a slightly better sense of how accurate that official location was because our Madhabdev University seismograph was closer to the epicenter than the stations used in the USGS location. This is still only a very preliminary analysis, but it provides a good illustration that having a good distribution of seismic stations near the epicenter of an earthquake is important for high-quality earthquake research, so that we know where (and how deep) the earthquake was. Better determination of those characteristics of the earthquake provides better resolution of the earthquake’s proximity to faults, other geological features that might be active, population centres, and built environment structures that are vulnerable to earthquake shaking. The more accurate we can locate earthquakes in Assam, the better we will be able to understand earthquake processes and earthquake hazards in the region. That is why we installed the Madhabdev University seismograph and why we would like to continue to increase the number of both low-cost, community science seismographs (like what we installed at Madhabdev University), as well as a full array of the (much more expensive) research-grade “broadband” types of seismographs across Assam.

AT: Besides Guwahati which are the most vulnerable areas.

Prof Alan: This is a question that always makes me worry about the possibility of choosing some specific areas over others and maybe missing some large future earthquakes in areas that have been dormant during the years we have been monitoring the region. And yet, this is perhaps the most direct earthquake seismology question that is of concern to people living in harm’s way of potentially tragic earthquakes. I would, therefore, like to explore this question as part of my collaborative research with CSIR-North East Institute of Science & Technology, Jorhat (CSIR-NEIST). Based on a quick review of the earthquake hazard situation in Assam, I noticed in some earthquake hazard maps that cover Northeast India, a general earthquake hazard approximately 5 to 10 times greater than that of the NEUS. The area around Guwahati looks, at a glance, to be about 5 times greater earthquake hazard than that of the NEUS, and the area around the recent tragic earthquake in Myanmar looks like about 10 times higher hazard than NEUS. This is just my first preliminary guess about this, and I would like to make one of the objectives of our research to see if we can narrow down the earthquake hazard variation across Assam and surrounding areas, while also paying attention to the possibility of large earthquakes in some “surprise areas”

AT: There is a network of around 20-25 seismic stations, deployed by different agencies to study the seismicity in the region. Is it enough, or more are required for in-depth studies to find out the causes of the tremors and other implications?

Prof Alan: Yes, I do think we need more seismic stations in this region. As I mentioned earlier, the official USGS location of the recent earthquake of 5.8 magnitude didn’t have any nearby stations to enable a precise location (the nearest station was about 360 km away from the epicenter). When I tried to do a preliminarily location that included our closer station in Madhabdev University (160 km away from the USGS location), I got a location that was about 10 km Northeast of the USGS location. I also got 42 km for the depth, compared with the USGS depth estimate is 29 km. This leaves too much uncertainty to do a sufficiently detailed analysis of just how close the earthquake was to geologically mapped faults and to vulnerable population centres. We will need more stations near future significant earthquakes to achieve the necessary resolution of these kinds of issues.

For effective seismic monitoring, I envision a well-monitored Assam with a combination of both many low-cost, community science seismographs as well as a full array of (much more expensive) research-grade “broadband” seismographs. I’ve learned about the initiative by CSIR-NEIST, in collaboration with ASDMA, Government of Assam, to install 45 seismic sensors integrated with up-to-date data recording and analysis for monitoring earthquakes and other natural hazards in Assam. This initiative also marks a significant advance in the emerging field of Environmental Seismology, a growing field that uses seismic waves to study processes associated with not only the solid earth, but also the atmosphere, oceans, glaciers, and human activity. The study of these phenomena is therefore applied to solving a wide range of environmental problems. I highly commend CSIR-NEIST for undertaking such a valuable initiative to upgrade all aspects of seismic monitoring for the greater good of the people of Assam and of the entire Northeast region of India.

AT: Quakes cannot be prevented, but what can be mitigated is the damage and casualties. How will you rate the Northeast in terms of preparedness and awareness?

Prof Alan: I feel that it is too soon in my educating myself about Northeast India earthquake risk to give an authoritative answer to this question (yet). There will always be tragic earthquakes, but there are things we can do to mitigate their effects and hopefully make ourselves less vulnerable to their powerful impact.

AT: How important are microzonation maps vis-a-vis building byelaws in such a seismically vulnerable region?

Prof Alan: Microzonation maps are critically important for every city in this region. They provide the scientific basis for implementing seismic design standards in new construction and for retrofitting older buildings that were not designed with earthquake safety in mind. Earthquake hazard microzonation, if done properly, can guide urban planners, engineers, and policymakers in making cities safer. However, as I mentioned earlier, the real challenge lies not only in preparing these maps, but also in ensuring their accuracy and—most importantly—their effective implementation. That is the task ahead of us.