Signs of Earthquake: How To Tell If Earthquakes Are Coming?

Do you know the subtle signs of earthquake that often appear before a quake hits? Strange animal behavior, sudden shifts in groundwater, and even unusual lights in the sky can all hint that the ground might start shaking soon. In this article, we will explore the most common warning signs of earthquakes, and explain how you can recognize them to stay safe. Let’s dive in!

Signs of Earthquake

Warning Signs of Earthquake

Warning signs of earthquake are often subtle and easy to miss, yet they can provide valuable clues before the ground starts to shake. 

• Unusual animal behaviors

Many reports suggest that animals may exhibit strange behaviors before an earthquake. 

For instance, pets might become agitated, and wildlife may flee their habitats. 

While these observations are anecdotal, they have been noted across various species.

Researchers believe animals could be sensitive to environmental changes preceding earthquakes.

• Foreshocks

Foreshocks are smaller tremors that sometimes occur before a major earthquake.

Not all earthquakes have foreshocks, and not all foreshocks lead to significant quakes. However, when they do occur, they can serve as a warning. 

• Ground deformation

Before a significant earthquake, the Earth's crust may deform.

This can manifest as tilting or uplifting of the ground. Such changes are often detected using precise instruments and can indicate accumulating stress along fault lines.

• Groundwater level changes

Sudden changes in groundwater can be one of signs of earthquake. 

Fluctuations in groundwater levels have been observed before major earthquakes.

These changes can result from shifts in the Earth’s crust, affecting underground water reservoirs. Monitoring wells can help detect these anomalies.

Sudden changes in groundwater can be one of signs of earthquake 

• Gas emissions

An increase in certain gases, like radon, can precede earthquakes. These emissions might occur due to the fracturing of rocks along fault lines, releasing trapped gases.

Monitoring gas levels in areas prone to seismic activity can provide early warnings.

• Unusual sky or light phenomenon

Phenomena such as earthquake lights - glowing orbs or flashes in the sky - have been reported before and during earthquakes.

The exact cause remains unclear, but these lights are believed to result from electrical charges in the Earth's crust.

While rare, they have been documented in various seismic events.

• Electromagnetic and Thermal Anomalies

Some studies suggest that electromagnetic and thermal anomalies, such as unusual readings in magnetic fields and temperature variations, can be signs of earthquake. 

Such anomalies are still under research, and their reliability as earthquake predictors is yet to be confirmed.

What are the signs of a big earthquake coming?

Are small earthquakes a sign of a big one?

Many people wonder if minor tremors indicate a larger earthquake is coming. In general, small earthquakes are not considered a reliable sign of a major quake.

Most minor quakes occur randomly and do not lead to a larger event. 

To better understand how tremors differ from full-scale quakes, you can read this detailed guide on the difference between earthquake and tremor.

However, there are exceptions. A series of small earthquakes near a locked fault zone can sometimes signal accumulating stress in the crust. This stress may eventually trigger a larger earthquake. 

For example, along the Hayward Fault near San Francisco in January 2019, several small quakes of magnitude 3.4-3.5 occurred a few miles from UC Berkeley.

These were followed by another earthquake in the same area. 

Do small earthquakes signal a larger earthquake coming?

What to do if you notice signs of earthquake?

Noticing signs of an earthquake means you need to act quickly. Even subtle hints, like minor tremors or unusual environmental changes, can give you precious seconds to protect yourself.

• Drop, Cover, and Hold On: If indoors, immediately drop to the ground, take cover under sturdy furniture like a table, and hold on. This protects you from falling objects and debris.

• Stay Away from Windows and Glass: Glass can shatter easily during tremors. Keep a safe distance from windows, mirrors, and glass doors to prevent injuries.

• Move Outdoors Only When Safe: If you are outside, move to an open area away from buildings, trees, and power lines. Do not rush into streets or areas with heavy traffic. Only leave buildings when you are sure it is safe.

• Be Prepared: Having an emergency kit with water, food, and first aid supplies is essential. Familiarize yourself with earthquake preparedness guidelines to stay ready for any situation.

Prepare an emergency kit before an earthquake

To better prepare for an incoming earthquake, read our full guide on earthquake preparedness!

Conclusion

Understanding the signs of earthquake helps you respond quickly and stay safe. Observing foreshocks, unusual animal behavior, or strange lights can give you valuable time to act and protect yourself and your loved ones.