Frequent Earthquakes in Mizoram: What’s Shaking India’s Northeastern Hills?
Part of the answer lies in geology. Mizoram lies in what India’s seismic map calls Zone V – the highest hazard zone. The entire northeastern region is wedged between colliding tectonic plates and active fault lines. India’s massive plate is still pushing northeastward at about 5 cm per year, crashing into Eurasia (to the north) and sliding under a Burma microplate (to the east) along the Indo-Burma subduction zone. This collision has built up the Himalayas in the north, while in Mizoram and neighboring Myanmar it causes complicated deformation and quakes. In fact, “the Indo-Burmese subduction zone is seismically more active compared to the rest of the region,” geoscientists note. Mizoram sits near the very edge of this subduction arc, meaning it inherits that high seismicity. As one study observes: “Mizoram is one of the states located in the proximity of the Indo-Burmese subduction zone” and has “witnessed many large earthquakes in the past, including the M7 event on 16 August 1938”. Since then, some 13 earthquakes of magnitude 6–7 and over 80 quakes of magnitude 5–6 have been recorded in and around Mizoram. (Historic examples in the broader region include the great Assam quake of 1897 (M8.1) and the 1950 Assam–Tibet quake (M8.7).)
In June 2020, Mizoram’s Champhai district (on the Myanmar border) saw a sudden surge of tremors. Researchers recorded a swarm of 20+ earthquakes over just a few weeks, with four shocks at or above magnitude 5.0. Locals told reporters they could feel multiple jolts each day. Studies (such as the 2022 IIT-Delhi/Ministry of Earth Sciences report) linked this cluster to deeply buried faults. Geologists at Pachhunga University College in Aizawl later reported that “the area was caught between two subterranean faults or cracks underneath”. In other words, Champhai may sit atop an intersection of hidden fault lines that were activated by stress. The state’s geology is very complex – folded layers of rock from ancient plate collisions. Mizoram lies in the Surma basin (formed by earlier India–Burma collisions) and is crisscrossed by old thrusts and strike-slip faults (the Churachandpur-Mao Fault, Naga Thrust, Dauki Fault, etc.). Modern surveys confirm the Surma sedimentary rocks here have been warped into steep, oblique folds. When such folded rocks rupture, they generate earthquakes.
Experts emphasize that northeast India is a “highly seismic zone.” Seismologist J.R. Kayal (one of India’s senior seismologists) remarked after a massive 7.7-Magnitude earthquake hit Myanmar (2023) that this part of the world is expected to shake. “A 7.7 Richter scale quake is a large quake in terms of seismology. It is not surprising as it is a highly seismic zone,” Kayal said, warning of likely aftershocks. Likewise, the National Centre for Seismology (NCS) noted that the region has a history of large quakes (“Northeast India also felt this trans-boundary earthquake … the region has a history of M 7 and above quakes”). Within Mizoram itself, the recent pattern of multiple 5+ tremors in a short time is highly unusual. As Kayal observed about the 2020 swarms: “There are 8-10 quakes of magnitude 5-6 within a few months in Mizoram, which is rare. We need to study if there is some link”. In short, the plates and local faults around Mizoram are under constant stress, and occasionally that pent-up energy bursts out as a series of quakes.
What drives the stress? Local experts point to the geometry of the plate boundary. Mizoram’s geology is dominated by an oblique collision. The Indian plate is moving roughly northward beneath the Burmese plate, but the convergence is strongly tilted. “The transverse fault and the Indian plate moving northward is causing stress along with the pressure from Myanmar’s side,” explained Mr. Sawma, an assistant professor at Mizoram University, after visiting quake-affected villages. In plain terms, India’s plate is shoving into Myanmar’s edge while also sliding past it, squeezing Mizoram’s folded crust. Sawma added that because “the folds are oblique, due to strain accumulation, rupture has been caused leading to earthquakes”. This agrees with the frontiers research that many quakes here are not classic megathrust events but occur on steep, oblique thrusts and strike-slip faults within the crust. In effect, the crust is like a distorted spring being twisted; when it snaps, it sends out shocks. The geology is so active that some researchers have warned a magnitude-8 or greater quake could eventually happen in the region – far beyond the magnitudes seen in 2020–23. (That scenario would be disastrous given modern population and building development.)
Even at moderate magnitude, the tremors have real effects on people. After the June 22, 2020 quake of magnitude 5.5 (centered near the border trade town of Zokhawthar), homes and churches were damaged in Champhai district. The Times of India reported cracks in buildings, fallen rocks on roads, and widespread panic. Mizoram’s Chief Minister Zoramthanga told media that “frequent earthquakes have resulted in fear, panic and psychological distress among the affected people,” noting that even relatively small quakes damaged 283 houses (loss about ₹3.16 crore) in the province. Many residents recall feeling the ground “suddenly jolting” and even hearing loud noises just before shaking began. In remote mountain villages, people fled outside at every tremor, leading to sleepless nights even during the rain. In mid-2020, some families indeed abandoned their homes and camped outside for fear of aftershocks, describing it as a “two-fold disaster” on top of the COVID-19 pandemic. Roads and utilities in hilly zones are also vulnerable: even minor quakes can trigger landslides or block roads in Mizoram’s steep terrain.
The socio-economic impacts have been worrying for the local government. Teachers and workers have described cracks splitting house walls. In response, Mizoram officials urgently requested help from New Delhi. The state’s Rajya Sabha MP even met ministry officials to demand a central seismology team study the swarm, set up an observation station, and advise on building safety. In fact, the Chief Minister formally asked for new “earthquake observation centres in eastern Mizoram” to improve warning and preparedness. Disaster authorities have compiled lists of damaged houses and are debating compensation for affected families. The anxiety is high: in 2020 one local geologist noted people were so shaken that maintaining COVID precautions in shelters became nearly impossible.
Geological History and Ongoing Research
Seismologists emphasize that Mizoram’s case is not about a single fault but a network of faults in a tectonically crumpled zone. Ongoing research (using records from 2020–2022) has started to map the active structures. For example, waveform analysis of the 2020 events found two distinct earthquake clusters along known faults. It confirmed that the Churachandpur-Mao Fault (a major strike-slip fault crossing Mizoram) is especially active. Computer simulations of very large hypothetical quakes (M8+) on that fault suggest peak ground accelerations could be severe for eastern Mizoram, underscoring the risk to foothill communities. At the same time, some data suggest many quakes occur within the subducting slab or on subsidiary thrusts, not necessarily on the shallow plate boundary.
Compared to the massive Himalayan quakes of the past (1950, 1897), the quakes in Mizoram have been moderate in size and relatively shallow (often 10–35 km deep). The 1938 M7 quake had a 75 km depth, so it caused little damage at the time. But today’s earthquakes, even if smaller, occur under denser population. Building codes in Mizoram have improved only slowly. Many hill villages still have unreinforced masonry or concrete houses on slopes. Scientists worry that without seismic-resistant design, even a magnitude-6 event could collapse vulnerable structures or trigger landslides in saturated soils.
Conclusions and Preparedness
In short, Mizoram’s frequent quakes are the result of its tectonic setting. The oblique collision of the Indian plate with the Burma microplate, the presence of multiple active faults, and the accumulation of strain in the folded crust all conspire to make Mizoram one of India’s most seismically restless states. As one review noted, “being in close vicinity of the Indo-Burmese arc (IBA), the Mizoram State is highly vulnerable to earthquakes”. Scientific experts agree more monitoring is needed: the region currently lacks dense seismic networks. NCS tweets provide real-time updates (e.g. the April 2023 quake was followed by locals feeling it far from the epicenter), but researchers would like more local instruments and cross-border data sharing with Myanmar.
For ordinary citizens, the lesson is caution and preparation. Individuals can secure heavy furniture, create emergency kits, and practice drills. Local governments must enforce building codes and plan evacuation routes. Meanwhile, geologists continue to study Mizoram’s faults – some even suggest remote sensing (satellite or airborne LIDAR) to map hidden fractures. The goal is to better forecast which areas are most at risk and how to reduce damage.
Overall, the geological verdict is clear: the earthquakes in Mizoram are not a mystery anomaly but a predictable consequence of plate tectonics. The Indian Plate’s relentless motion under Burma has “activated” old faults and created new ones in the hilly frontier. As Mizoram’s chief minister warned after 2020 quakes, the tremors have already inflicted damage and fear. Understanding the causes – through studies like those in *Frontiers* and close monitoring by NCS – is the first step toward mitigating impact. In the words of local geologists, this is “a two-fold disaster” when combined with other challenges (like the pandemic). But by taking the science seriously (and perhaps accepting that “it is a highly seismic zone”), Mizoram can improve its preparedness. Future research and expert collaboration will continue to unravel the seismic puzzle of Mizoram, and help keep its people safer as more tremors come.
