Why Do Earthquakes Occur? Essential Preventive Measures to Minimize Damage

Earthquakes happen when stress builds up along fault lines in the Earth’s crust and is suddenly released, sending seismic waves through the ground. This movement is driven by the shifting of tectonic plates, which cover the planet like a jigsaw puzzle. In India, seismic activity has risen in 2025, with 768 earthquakes recorded through July, a significant jump over the annual average of 370 events. Notable recent tremors included a 4.4 magnitude quake in Jhajjar, Haryana, on July 10 and a 4.0 magnitude tremor near Delhi on February 17.

Types of Earthquakes

There are four main types of earthquakes:

• Tectonic: Caused by plate movements along faults (most common).

• Volcanic: Triggered by magma shifting beneath a volcano.

• Collapse: Occurs when underground caverns or mines cave in.

• Induced: Result from human activities such as reservoir filling or hydraulic fracturing

Earthquake Magnitude vs. Earthquake Intensity

Magnitude measures the energy an earthquake releases at its source using the Richter or moment magnitude scales. Each whole-number increase signifies a tenfold energy jump. Intensity gauges the quake’s effects at different locations, often using the Modified Mercalli Intensity (MMI) scale from I (barely felt) to XII (total destruction). The July Jhajjar quake was magnitude 4.4 but registered intensity IV near the epicenter and III up to 100 km away.

How Earthquakes Are Predicted

Precise earthquake prediction, pinpointing when, where, and how strong a quake will be, is not yet possible. Instead, seismologists use historical earthquake data and probabilistic seismic hazard assessments to estimate risk. The India Meteorological Department (IMD) maps past seismic events, plate boundaries, and fault lines to issue alerts, though exact forecasts remain out of reach.

Understanding the Epicenter and Fault Lines

The epicenter lies directly above the focus, the subsurface point where the quake begins. Shallow quakes (0–70 km deep) cause stronger surface shaking. Delhi and the surrounding region sit on several active faults, like the Delhi–Haridwar Ridge, which explains why 17 quakes struck Delhi-NCR in 2025, all at shallow depths of 5–10 km.

The Role of Earthquake Sensors and Monitoring Systems

India’s National Centre for Seismology maintains over 160 seismic stations, including broadband sensors and accelerographs, as part of a National Seismological Network. The IMD also operates 82 observatories, along with VSAT-linked digital telemetry across Delhi–NCR and Northeast India. Plans are underway for a smart early warning system in the Indian Ocean, featuring underwater seismometers and pressure recorders to detect tsunamis and quakes.

Earthquake Preparedness: Steps to Take Before the Ground Shakes

Effective earthquake preparedness can save lives and property. Key measures include:

• Identify safe spots such as sturdy tables or interior walls.

• Secure heavy furniture, lighting fixtures, and appliances to prevent toppling.

• Repair deep cracks in walls and ensure gas connections are sound.

• Develop an earthquake emergency plan with evacuation routes and family meeting points.

What to Include in an Earthquake Survival Kit

A well-stocked earthquake survival kit should last at least 72 hours and contain:

• Battery-operated torch, radio, and extra batteries.

• First-aid kit with manual.

• Non-perishable food and sealed water (3–4 liters per person per day).

• Essential medicines, important documents in waterproof pouches, and emergency cash.

• Mobile phone, chargers, power bank, and sturdy shoes.

Earthquake Safety Tips: How to Stay Safe During and After a Quake

During a quake, Drop, Cover, and Hold On under a table or next to an interior wall, away from windows and heavy objects. If outdoors, move to an open area clear of buildings and power lines. After the shaking stops, check for injuries, gas leaks, or structural damage. Expect aftershocks and remain vigilant. The BhooKamp app allows citizens to report felt quakes, aiding rapid damage assessment. It logged 49 felt reports within two hours of the Jhajjar quake in July 2025.

Building resilient structures is key to earthquake prevention. India’s Seismic Zone IV regions, including Delhi, must follow the Bureau of Indian Standards (BIS) codes for earthquake-resistant design. As monitoring technologies advance, India’s earthquake preparedness and early warning capabilities continue to improve, reducing potential earthquake damage across the nation.