January 10, 2025

Abram Tran

12th Grade

Westminster High School

Causes and Effects of Earthquakes

The earthquake. A terrifying phenomenon often regarded as one of the most dangerous natural disasters on the planet, being only about 8% of all natural disaster occurrences but causing up to 58% of total human deaths according to the United Nations Office for Disaster Risk Reduction (UNDRR). Its power was often regarded by ancient people as the work of a god, with the Ancient Greeks assigning its power to Poseidon, who was second in power only to Zeus. 

Earthquakes occur when tectonic plates, often the size of entire continents, shift and collide with each other. As they collide, parts of each plate become stuck to the other, and as the rest of the plates move, friction and tension build-up. As the plates finally separate, this tension is released, releasing energies equivalent to up to thousands of times the most powerful nuclear weapons. The power of the earthquake is ranked on the Richter Scale, going fro

Humanity’s Fight Against Earthquakes

Over a dozen different countries exist in the Ring of Fire zone. This zone encompasses the whole Pacific Ocean and contains 90% of all documented earthquakes. As a result, countries in this area have developed simple solutions to fight back against powerful earthquakes. A common trend noticed was how earthquakes would cause buildings to sway side to side, or move unintentionally. This would cause structural damage to the building as concrete has little flexibility, weakening its structure over time or taking it down outright. But how have engineers managed to fight against this effect?

Japan

Japan is one of the world's most developed nations but is also one where earthquakes are frequent and powerful, with up to 1,500 earthquakes annually. Though many of the earthquakes are lower-magnitude ones, they would still be enough to cause damage to structures if not dealt with. Additionally, several powerful earthquakes hit Japan, including the 2011 Tohoku earthquake. At a magnitude of 9.1, it is the 4th most powerful seismic event ever documented.

To combat earthquakes, Japanese engineers developed the Menshin and Seishin techniques. The Menshin technique is the main technique when fighting earthquakes, and utilizes a system of massive rubber dampeners at the foundation of the structure to allow for the building to move horizontally with the earthquake. This gives the building flexibility, allowing them to resist the side effects of unnecessary saying. The Seishin technique complements the Menshin systems and works by inserting dampeners within the building to help absorb further seismic energy. Combined, they can absorb most of the energy coming from earthquakes and prevent harm to the superstructure. The use of both systems effectively makes the buildings invulnerable to earthquakes, with most buildings not even needing to be repaired after an earthquake.

Taiwan

Taiwan, like Japan, is situated on the Ring of Fire and has dealt with its fair share of earthquakes. As recently as April of 2024, Taiwan was hit with a magnitude 7.4 earthquake. Despite such a catastrophe, Taiwan’s tallest building, the Taipei 101 was able to withstand the event completely unharmed.

The Taipei 101, unlike Japanese buildings which rely on dampening the effects of tectonic activity, uses a massive 660 tons pendulum to counter the swaying caused by it directly. When the structure of the Taipei 101 begins to shake, the massive pendulum swings in the opposite direction. This is because the pendulum is suspended, meaning its movement is delayed relative to the rest of the building. The swinging of the pendulum will then be in the opposite direction of the sway of the building, fighting against the kinetic energy of the earthquake. Excess kinetic energy from the pendulum is then converted into heat by hydraulic machines.

Chile

On the other side of the Pacific, Chile rests on the opposite end of the Ring of Fire. In 1960, a magnitude 9.5 Valdivia earthquake hit the nation, causing the most powerful earthquake ever documented. Unlike Japan and Taiwan, Chile lacks a strong economy and cannot afford advanced systems to counter earthquakes. Rather, it relies on seismic building codes to negate the harm.

Chile's seismic building code was developed in the early 1900s, with several revisions added as new knowledge was gained. Its main goal was to make the most use of Chile’s resources in combating earthquakes and included protocols and study efforts to better negate future events. A main part of the earthquake resistance of Chilean structures is reinforcing the concrete. Adding rebar, a type of steel bar used in construction, to the inside of the concrete, allows the concrete some flexibility, helping negate the impact of earthquakes. Another technique is floor density. In 1985, it was noticed that buildings with a shear wall surface-to-floor ratio between 5-10%often survived better. This was because density impacted the ability to absorb seismic energy, with taller buildings performing better with higher densities.

Conclusion

Across multiple different countries, earthquakes are an issue that can wreak havoc on their communities. Fortunately, brilliant engineering and simple decisions have contributed to a design process to make structures earthquake-proof. From the use of rubber dampeners in Japan,  the powerful pendulum used by the Taipei 101, to the addition of rebar to concrete, humanity finds ways to innovate and adapt its way around disaster.