UPHEAVALS IN EARTH

Long back, a large collection of material masses coalesced and formed the Earth – it was a single crust or plate with no oceans - like a hard-boiled egg. Over time this single shell or plate started to split and drift into separate plates of land or ocean crusts. Now the surface looks like spherical jigsaw puzzle, all the plates fit together. The tectonic plates play crucial role in causing earthquakes. The earthquakes have been occurring throughout Earth's history, but our ability to document them only goes back to ancient Chinese records. The earliest recorded evidence of an earthquake dates back to 1831 BC in the Shandong province of China, but the recording began around 780 BC during the Zhou Dynasty.

Plate Tectonics

The surface of the Earth-the Lithosphere consists of seven major tectonic plates and many smaller ones. The Pacific Plate is the largest, covering one-third of the planet's surface, active tectonically causing earthquakes and volcanic activity, with collision of European plate and the Philippines plate. These plates are in constant slow motion in different directions and at different speed from those of neighbouring ones. Sometimes the plates collide and form mountains. Sometimes two plates move away from one another - creating rifts. In another case, two plates move side-by-side, along the same direction or in opposite directions. These three types of inter-plate interactions are the convergent, divergent and transform boundaries.

How does it happen?

When the Earth's tectonic plates move against each other, they put force on themselves and each other. When this stress/force is great enough, the lithosphere breaks or shifts, causing faults. When the break occurs, stress is released as energy, which moves through the Earth in the form of waves called the seismic waves - this causes a sudden shaking of the ground which we call an Earthquake. Earthquakes occur when the rock on one side of a fault slips relative to the other. The fault surface can be vertical, horizontal or at an angle. The faults and seismic waves are the main causes of Earthquakes.

Earthquakes are the most frightening natural hazards, occurring with no warning. Like any other natural process earthquakes are bound to happen.

Earthquakes are occurring almost every day throughout the world. From first week of February 2025 there have been 977 quakes of more than 4.0 magnitude (m), till first week of March. It struck in countries like Ecuador, Sumatra, Peru, Chile, Myanmar, Southern Iran, Mid-Indian Ridge, Bay of Bengal, Fiji Islands, Ethiopia, Solomon Islands, Southern Chile, Myanmar, off coast of Peru, Ethiopia, Alaska, Solomon Islands, Fiji Islands and many others.

Recent Events

In January 2025, an earthquake struck Shigatse city of Tibet, killing 400 people. It was also felt in Nepal and northern India. On the New Year’s Day 2024, quake struck the west coast of Japan, generating moderate tsunami. This resulted in uplift of coastline upto 250 m. In February 2023 there was a quake along Turkey -Syria border in the early-morning, there were two consecutive quakes of almost same magnitude, killing 50,000 people and razing entire building stock of the region. In 2015 Tohoku earthquake created devastating tsunami, damaging Fukushima Nuclear plant. The prediction was of 7.5 m but it turned out to be 9.0 m, causing largest tsunami in Japan.

There was a mild magnitude earthquake in New Delhi on 17th February 2025, which shook buildings. Within four hours it was also observed in Siwan, Bihar. In March 2025, earthquake struck in Lobujya, Nepal, Imphal, Bobdila, Arunachal Pradesh, February - Paradeep Garh, Odisha, Kathmandu, Guwahati. However, there have been quakes in the recent past, March 2023, North India, Nepal, 153 killed in Nepal. October 2005, India (Kashmir), Pakistan, Afghanistan, killing 50,000.

The Indian Himalayas are the smoking gun for earthquakes. At the same time Himalayas are over exploited by increasing human-induced activities in the mountains like massive constructional projects, beyond carrying capacity of the ecosystems. The infrastructural development in Himalayas region must be viewed. While several projects are intended to smooth the movement of people and goods, the recurring landslides and glacial lake outbursts that wash away dams, hydropower projects, and roads serve as a constant reminder of the inherent fragility of the region. Every form of infrastructure in the region – power plant or dam – must take into account the imminence of a major earthquake. There is need to follow existing building codes, not only in Himalayas but in the surrounding Indo-Gangetic plains, which can go a long way in limiting the inevitable damage.

Be prepared for the next

There are places where earthquakes occur more frequently and their histories foretell that future will be no different. The San Andreas fault is the best studied in the world, the scientists caution a threat of earthquake across San Francisco Bay region, a major one before 2032. Hence scientists have informed the people to be prepared for it. The same is situation of California, where people live above potent fault line knowing well that there is likely an earthquake one day. Seismologists have also cautioned about the impending earthquake in Himalayas, in the foothills and plains. Himalayas produced three great earthquakes in 1905, 1934 and 1950 but none afterwards. Seismologists are of the view that in central Himalayas may be a future great earthquake. There is very long interval in releasing the accumulated stress. The moderate quakes like Uttarkashi, Chamoli in the early and late nineties and Nepal in 2015 have left the gap unfilled. In the Himalaya region the projects like 900 km long Char Dham is worrying as 8m wide road may lead to landslides, floods and earthquakes. It needs to be viewed seriously. However, it is pertinent to have seismic analysis of the area which are prone to seismic activities for construction of structures like buildings and bridges etc.

Earthquakes loom large as major catastrophic events due to their substantial magnitude and the potential to trigger ancillary hazards like landslides, fires, and tsunamis. This multi-faceted nature of seismic events underscores their capacity to wreak havoc, causing significant losses and damages. The earthquakes are the least predictable natural disasters which impact the environment, economy, lives, and properties.

Geoscientists and researchers have been making continuous efforts, we may expect breakthrough in forecasting, especially to the areas of major subduction zones, after recording their high-density data to develop AI models. While the efforts so far in earthquake prediction have not been effective, rapid strides in technology will certainly help in forecasting and mitigating natural disasters.