Earthquake Survey Reveals Largest Tectonic Activities This Year; How Is the Strength of Tremors Measured?
(Photo : Wikimedia Commons/ Astroskiandhike)

Hundreds of earthquakes occur worldwide every day. However, most are rarely felt since they are only of magnitude two or smaller. Only the notable ones, usually of magnitude six or higher, can damage populated areas.

Earthquake Map

Recently, seismic experts have meticulously mapped out the most significant earthquakes projected to occur worldwide in 2024. These predictions are based on the seismic activity of a magnitude of 6 or higher. Among these, the two most substantial earthquakes of the year occurred in Taiwan and Japan, capturing global attention and emphasizing the importance of earthquake preparedness.

Other tremors of magnitude six or higher happened in Afghanistan, Brazil, Vanuatu, Macquarie Island, Papua New Guinea, Philippines, Tonga, China, Guatemala, and Indonesia. The U.S. Geological Survey classified these tremors as 'significant' based on a combination of factors. These include the magnitude of the earthquake, the level of alert triggered on the USGS's 'Did You Feel It?' page, and the number of people who reported feeling the earthquake. This classification system helps to provide a standardized way of categorizing earthquakes based on their potential to cause damage and impact communities.

On January 1, the Noto Peninsula in Japan was struck by a magnitude 7.5 earthquake, while a magnitude 7.4 tremor was experienced south of Hualien City in Taiwan on April 2. According to earthquake engineering expert Jonathan Stewart from the University of California, Los Angeles (UCLA), both incidents are notable. Stewart points out that the Noto Peninsula earthquake was significant not only because of its magnitude but also because it caused the first major tsunami warning in Japan since 2011. He also highlights the Hualien earthquake as the strongest in Taiwan since 1999, emphasizing the need for further research and preparedness in the region.

The earthquake in Japan, with its epicenter in the Noto Peninsula, left a trail of destruction, particularly in Wajima, Suzu, Anamizu, and Noto. The violent shaking also devastated the nearby communities of Niigata and Toyama, resulting in approximately 245 fatalities. This tragic event underscores the devastating potential of earthquakes and the need for comprehensive disaster management.

Large earthquakes in Japan are not rare since it is one of the most tectonically active countries in the world. Japan is located along the Pacific Ring of Fire, a major area in the basin of the Pacific Ocean where a large number of earthquakes and volcanic eruptions occur. This is due to the fact that Japan is atop four tectonic plates that constantly rub together. Almost 1,500 shakings happen in Japan yearly, although most are not felt.

However, massive earthquakes like this are not often reported. For instance, what makes the Noto Peninsula earthquake notable is not just its magnitude, but the fact that it caused the first major tsunami warning in Japan since the devastating 2011 Tohoku earthquake and tsunami. This is significant because it underscores the potential for large earthquakes to trigger destructive tsunamis, highlighting the importance of early warning systems and preparedness.

Meanwhile, the Hualien earthquake in Taiwan was the strongest since 1999. More than 1,000 people were injured, and at least 18 people died. According to Stewart, there are many areas of research to focus on regarding tremors of this size.

Scientists emphasized the need to understand the hazard of earthquakes of this size, focusing on the amount of permanent ground deformation resulting from faulting. This refers to the permanent changes in the landscape that occur as a result of the movement of the Earth's crust along a fault line during an earthquake. These changes can include the formation of new landforms, the displacement of existing features, and the alteration of drainage patterns. Understanding these changes is crucial for assessing the long-term impacts of earthquakes on the environment and for planning and implementing effective mitigation measures.

READ ALSO: Japan's 7.6-Magnitude Earthquake Transformed Noto Peninsula With Newly Elevated Coastlines By Up to 820 Feet, Satellite Photos Reveals


Earthquake Measurements: Magnitude Vs Intensity

Understanding earthquake measurements is crucial for comprehending the magnitude and impact of these natural disasters. Earthquakes can be quantified in terms of magnitude and intensity. Magnitude is a measure of the energy released at the source of an earthquake, while intensity gauges the ground shaking at a specific location. The moment magnitude scale and the Modified Mercalli scale are the commonly used scales in the U.S., providing a standardized way to communicate the Severity of earthquakes.

In the moment magnitude scale, a complex mathematical formula converts ground motion recorded with a seismometer into a magnitude number that represents the amount of energy released during an earthquake. In this scale, the energy released for each whole number measurement is about 31 times greater than that of the previous whole number.

On the other hand, measurements on the Modified Mercalli Intensity scale are solely based on damage assessments and eyewitness accounts. Generally, intensity measurements near the source of the tremor are higher than those at a distance.

RELATED ARTICLE: Taipei 101 Survived the Magnitude 7 Earthquake That Hit Taiwan; Here's How the Country's Tallest Skyscraper Withstood the Nation's Strongest Quake in 25 Years

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