Earthquake Myths vs. Facts

Earthquakes, those powerful geological events that have both fascinated and terrified humans for centuries, continue to be a topic of intrigue. Yet, amidst the fascination, there exist numerous misconceptions and myths that often shape our understanding of these seismic phenomena. In our quest for knowledge and resilience, it becomes imperative to differentiate truth from falsehood, separating the seismic facts from the seismic fiction. In this blog post, we’ll explore some common earthquake myths and shed light on the facts.

Myth 1: Earthquakes Only Happen in Certain Parts of the World

Fact: This myth assumes that seismic activity is exclusive to specific regions, such as California’s notorious San Andreas fault, or regions that lie on the Ring of Fire. However, the reality is that earthquakes can strike almost anywhere on Earth. Our planet’s crust consists of tectonic plates and movement occurs along their boundaries or within them (so-called intraplate earthquakes). While some areas experience more frequent quakes due to plate interactions (like the Pacific Ring of Fire), no place is entirely immune. The central United States and some European countries, far from plate boundaries, have witnessed significant earthquakes.

Myth 2: Earthquake Activity is Increasing Globally.

The notion that earthquake activity is increasing globally is a common misconception. In reality, there's no evidence to support the idea that the frequency or severity of earthquakes is on the rise on a global scale.

Today, we have sophisticated seismic monitoring networks worldwide that can detect even small earthquakes, even with negative magnitudes). This increased monitoring capability means that more earthquakes are being recorded now than in the past. Therefore, it may seem like there's an increase in earthquake activity when, in fact, we're just better at detecting them.

Additionally, human populations are growing, and more people are living in urban areas in regions prone to earthquakes. As a result, when earthquakes do occur, they tend to cause more damage and receive more attention due to the higher population density and infrastructure in affected areas. This increased exposure can lead to the perception that earthquake activity is increasing.

Furthermore, advances in communication technology allow news of earthquakes to spread rapidly around the world. As a result, people are more aware of earthquakes that occur in distant regions, contributing to the perception of increased seismic activity.

Picture 1: Earthquakes occurred globally from April 17, 2019, to April 16, 2024, from Quantectum’s GIS.

Myth 3: Animals Can Predict Earthquakes

Fact: While anecdotal evidence suggests that animals exhibit unusual behavior before quakes, there’s still no scientific proof. Some believe that animals sense vibrations or changes in electromagnetic fields. However, no consistent correlation exists. Relying on animal behavior for early warnings is unreliable; we must rely on scientific monitoring and preparedness measures.

The earliest recorded instance of unusual animal behavior before a significant earthquake dates back to 373 BC in Greece. Rats, weasels, snakes, and centipedes reportedly left their homes and sought safety several days before a destructive earthquake.

Myth 4: Small Earthquakes Prevent Larger Ones

Fact: Some believe that small tremors release built-up energy, preventing more massive quakes. However, each earthquake is independent. While small earthquakes do relieve some stress along a fault, they typically do not significantly affect the likelihood of larger earthquakes. While small earthquakes don’t prevent large ones, they serve as valuable indicators. Seismologists often observe that minor quakes precede major ones. Preparedness remains essential regardless of quake size.

Myth 5: You Should Stand in a Doorway During an Earthquake

Fact: In the past, doorways were considered safe shelters due to their perceived structural strength. However, modern building codes and construction techniques have improved overall building integrity. Doorways are no longer the safest spots. Instead, follow the “drop, cover, and hold on” protocol. Seek shelter under sturdy furniture, protect your head and neck, and stay away from windows and heavy objects. Doorways are no longer the go-to choice during seismic events.

Myth 6: The “Triangle of Life” Method Is Safer Than “Drop, Cover, and Hold On”

Fact: The “triangle of life” advises:
- Lying next to furniture: Rather than taking cover under it, individuals should lie beside furniture.
- Void spaces: The theory assumes that void spaces created by collapsed structures can provide safety. These void spaces occur when a building’s roof collapses and lands on furniture or other contents.

Advocates of the Triangle of Life believe that lying in these void spaces is safer than using furniture as cover. However, experts dispute this method. “Drop, cover, and hold on” remains the recommended practice during earthquakes. It not only saves lives but also reduces panic and chaos by avoiding running during shaking. Remember, you cannot outrun an earthquake—taking cover is crucial.

Picture 2: Drop, cover, hold on – earthquake emergency measure for protection.

Myth 7: Earthquakes Only Occur Underground

Fact: While earthquakes are commonly associated with underground movements of the Earth's crust, they can also occur underwater, which is known as submarine earthquakes, or even on the surface, known as shallow-focus or shallow-depth earthquakes. We know:

- Underground Earthquakes: These are the most common types of earthquakes and are caused by the sudden release of energy in the Earth's crust due to the movement of tectonic plates. This movement can cause the crust to deform, leading to stress buildup and eventually rupture along fault lines. The resulting seismic waves propagate through the Earth, causing the ground to shake.

- Submarine Earthquakes: Earthquakes that occur underwater are known as submarine earthquakes. They have the same underlying causes as underground earthquakes, resulting from the movement of tectonic plates beneath the ocean floor. Submarine earthquakes can also trigger tsunamis if they displace large volumes of water.

- Shallow-focus Earthquakes: These earthquakes occur relatively close to the Earth's surface, typically within 70 kilometers (about 43 miles) below the surface. They are characterized by their relatively shallow depth compared to deeper earthquakes, which can occur several hundred kilometers beneath the surface. Shallow-focus earthquakes can cause significant damage, particularly in populated areas, due to their proximity to the surface.

Myth 8: Buildings Collapse Solely Due to Shaking

Fact: While seismic shaking is indeed a primary cause of structural damage during earthquakes, buildings rarely collapse solely due to shaking. Instead, collapses usually result from a combination of factors, including design flaws, poor construction quality, inadequate maintenance, and even soil conditions.

Buildings designed and constructed without proper consideration of seismic forces are more vulnerable to collapse. This could involve insufficient reinforcement, improper material selection, or flawed architectural designs that cannot withstand the lateral forces generated by earthquakes.

Additionally, the type and condition of the soil upon which a building is constructed can significantly affect its response to seismic shaking. Soft or loose soils can amplify ground motion, increasing the risk of structural failure. Similarly, liquefaction, where soil temporarily loses its strength due to saturation during an earthquake, can compromise a building's stability.

In some cases, localized factors such as nearby construction activities, changes in groundwater levels, or even the presence of heavy equipment on upper floors can contribute to building collapses during earthquakes.

Picture 3: Collapsed building after magnitude 6.4 quake in Hualien on February 6, 2018.

Myth 9: Small Earthquakes Can't Cause Significant Damage.

Small earthquakes—those with magnitudes below 4.0—may seem harmless, but appearances can deceive. Even minor shaking can stress buildings, bridges, and infrastructure. They can weaken the ground beneath structures, compromising their stability, or act as precursors, releasing stress and potentially triggering more significant seismic events.

For example, a series of small earthquakes preceded the devastating 2011 Christchurch earthquake. These foreshocks weakened buildings, exacerbating the impact of the main quake.

Whether it’s a gentle sway or a violent jolt, preparedness is key. Strict construction standards ensure resilience against even small quakes. Having supplies ready can make a difference.

Myth 10: Earthquakes Can be Triggered by the Alignment of Planets.

The cosmos, with its planets and stars, has long fascinated humanity. Ancient civilizations attributed significance to planetary alignments, believing they influenced earthly events. But what about earthquakes? Can the alignment of planets truly shake our world?

The myth that earthquakes can be triggered by the alignment of planets is a persistent misconception that has been debunked by scientists.

Firstly, there is no scientific evidence to support the idea that planetary alignments can cause earthquakes. While gravitational forces exerted by celestial bodies like the moon can influence tidal patterns on Earth, the gravitational pull exerted by planets is far too weak to have any significant effect on tectonic activity.

Secondly, earthquakes are primarily caused by the movement of tectonic plates along faults in the Earth's crust. These movements occur due to geological processes such as plate tectonics, volcanic activity, and fault slippage. Planetary alignments do not have any direct influence on these processes.

Sometimes, people may perceive a connection between planetary alignments and earthquakes due to confirmation bias, where they selectively remember instances when earthquakes coincided with such alignments while ignoring the countless times when they did not.

Conclusion

In our quest to understand earthquakes, it's vital to distinguish fact from myth. From uncovering the regional exclusivity to the belief in planetary alignments triggering seismic activity, each myth examined underscores the importance of scientific inquiry. By separating fact from fiction, we stand firm in our pursuit of truth and understanding, poised to navigate the seismic forces shaping our planet.

Sources:
1) CSUSM. Earthquake Myths and Facts. Accessed on: 15-Apr-2024. Available at: https://www.csusm.edu/em/procedures/earthquake_myths.html
2) USGS. Can the position of the moon... Accessed on 15-Apr-2024. Available at: https://www.usgs.gov/faqs/can-position-moon-or-planets-affect-seismicity-are-there-more-earthquakes-morningin-eveningat