Buzz
Of all natural disasters, earthquakes are arguably the most unpredictable and destructive. The severe destruction they cause has led to their longstanding fear throughout history. With no scientifically validated way to predict earthquakes (at least not yet), the key lesson we’ve learned from previous events is that prevention strategies are far more dependable than attempts at forecasting. Rather than relying on outdated myths (like standing in doorways during an earthquake), we should focus on educating ourselves about earthquake engineering as the most effective means to reduce damage and save lives.
10. The Phenomenon of Earthquake Lights
For centuries, people have reported seeing strange lights in the sky just before or during major earthquakes. These lights have been described in various ways, such as bright flashes, blue flames, or faint rainbows that appear to rise from the ground, sometimes stretching up to 200 meters (650 feet). Prior to the 1960s, geologists dismissed these accounts as mere hallucinations due to the lack of photographic or video evidence. However, this changed in the mid-1960s after a series of earthquakes struck Nagano, Japan, providing skeptical geologists with a rare opportunity to document and accept the phenomenon as real.
Various theories have been proposed to explain the origin of earthquake lights. One theory suggests that the lights are caused by a disruption in the Earth's magnetic field, triggered by the piezoelectric effect in quartz rocks under tectonic stress. However, since not every major earthquake is preceded by such lights, these theories remain unproven and continue to be explored.
9. Soil Liquefaction
Most of us know about quicksand, which is famous in movies and cartoons for its ability to swallow people. In reality, quicksand isn’t as terrifying as we were led to believe in our childhood. However, there is another type of quicksand that truly deserves our concern—soil liquefaction.
Along with tsunamis and landslides, liquefaction is another dangerous consequence of earthquakes. This phenomenon happens when loosely packed, water-saturated soil experiences strong earthquake vibrations, causing the soil to lose its strength and stability. As a result, anything relying on the soil for support, such as buildings, roads, or vehicles, will sink or topple over. This was clearly demonstrated in 1964 when an earthquake combined with unstable subsoil triggered liquefaction that destroyed or damaged 16,534 houses in Niigata, Japan. Liquefaction was also largely responsible for the significant damage to roads, cars, and other structures during the 2011 Christchurch earthquake.
8. Earthquake Storms
The sight of collapsed buildings, lifeless bodies, and shattered communities may seem like the peak of an earthquake’s devastation. However, according to the earthquake storms theory, this is not always the end of the story. Developed by Stanford professor Amos Nur, who studied a range of ancient and modern earthquakes he believed were connected, the theory posits that a single earthquake can trigger a sequence of large tremors along the same tectonic plate boundary. These subsequent quakes can occur months or even years later.
Nur’s theory finds support in a series of major earthquakes along the North Anatolian Fault in Turkey, spanning from 1939 to 1999. Of the 13 significant quakes in the region, seven occurred in a regular, predictable pattern. Each earthquake struck a section of the fault immediately to the west of the previous one. Nur attributed these recurring quakes to the stress transfer that follows each seismic event.
7. Reelfoot Lake
While earthquakes are often associated with death and devastation, they can also have positive effects. A prime example of this is Reelfoot Lake in Tennessee, which was formed by the New Madrid earthquakes that struck the Mississippi Valley in 1811 and 1812. After one of these earthquakes, eyewitnesses reported seeing the Mississippi River flowing backward for several hours, a result of a phenomenon called a “fluvial tsunami.”
The earthquake also caused the land in the area to subside, with depths ranging from 1.5 to 5.9 meters (4.8 to 19.2 feet). This sinking allowed the river’s water to flow into the depression, creating a lake. Over time, this newly formed lake became a rich habitat for various plant and animal species. Today, Reelfoot Lake is a popular spot for boating, hunting, and fishing activities.
6. Ice Quakes
Ice quakes (also known as frost quakes or cryoseisms) occur when moisture trapped under the ground freezes rapidly and expands. This sudden expansion creates pressure, which is then released, causing the ground to crack and producing a loud, booming sound. Ice quakes have been reported in Canada and the northeastern United States, where they are often mistaken for earthquakes.
This rare event typically happens when temperatures drop suddenly to below freezing. It may be accompanied by tremors similar to those of an earthquake, but unlike quakes, the effects of a cryoseism are confined to a small area, as the vibrations do not travel far. In some instances, people just a few hundred meters from the epicenter may not notice or hear anything.
Due to their rarity, there is limited scientific data on cryoseisms. Most of the information available comes from news reports and firsthand accounts. It is generally believed that cryoseisms are harmless, aside from the frightening sounds they produce, which can wake up entire cities during the night.
5. The Cities That Moved
Chile is renowned for being the site of some of the world’s most powerful earthquakes. This is largely due to the country’s location near the Ring of Fire, where two of the Earth’s tectonic plates are constantly colliding.
In 2010, one earthquake in particular was deemed by the scientific community as one of the most significant earthquakes ever studied. This recognition isn’t because of the 523 lives lost or the 1.5 million people left homeless, but because of its immense force, which actually caused the city of Concepcion to shift 3 meters (10 feet) to the west.
Concepcion was not the only city affected by the quake. Other cities, including the Chilean capital Santiago, shifted by about 28 centimeters (11 inches), while even Buenos Aires, located 1,300 kilometers (810 miles) away, experienced a shift of nearly 4 centimeters (1.5 inches). These measurements were recorded by teams from four US universities who compared GBS data before and after the 8.8-magnitude quake.
4. Sunquakes
Quakes are not limited to Earth. Scientists have discovered that even the Sun experiences seismic waves similar to those on our planet. This phenomenon, known as a sunquake, was first observed on July 9, 1996, when a solar flare caused a quake with 40,000 times the energy of the devastating 1906 San Francisco earthquake.
The sunquake, equivalent to an 11.3-magnitude earthquake, created waves that resembled ripples in water. However, unlike water ripples, these waves accelerated from an initial speed of 35,000 kilometers per hour (22,000 mph) to a staggering 400,000 kilometers per hour (250,000 mph) before fading into the Sun’s photosphere. Dr. Craig Deforest, a researcher with NASA and ESA, noted that the energy released was equivalent to covering the entire Earth in dynamite and detonating it all at once.
3. Earthquakes’ Effect On Days
In addition to displacing cities, liquefying soil, and generating massive tsunamis, earthquakes can also speed up the Earth's rotation. NASA scientists discovered this after the 8.9-magnitude earthquake that struck Japan's coast in 2011. Their analysis revealed that the tremor caused the Earth to spin faster, shortening the day by 1.8 microseconds. This acceleration was the result of a shift in the planet’s mass distribution, with more mass moving toward the equator.
This is not the only time such an effect has been observed. A similar phenomenon occurred during the 2004 Sumatra earthquake, which shortened the day by 6.8 one-millionths of a second. The same happened with the 2010 Chilean earthquake, which sped up Earth’s rotation by 1.26 one-millionths of a second. While these changes may seem minimal, the cumulative impact of every earthquake of similar magnitude over time could be substantial.
2. The Quake Island
On the morning of September 24, 2013, a 7.7-magnitude earthquake struck southwest of Balochistan, Pakistan. This was followed shortly by the emergence of a new island, located 2 kilometers (1.2 miles) off the coast of Gwadar. The island, named Zalzala Jazeera (“The Quake Island”), is believed to be a mud volcano.
Despite the significant attention the island garnered both locally and internationally, its appearance was not unexpected. Longtime residents of the coastal town remembered seeing an island appear in the same spot after a 1968 earthquake that struck the region.
Standing 18 meters (60 ft) tall and stretching over 175 meters (576 ft), Zalzala Jazeera has become a notable tourist destination in the region. However, this may not be the case for long, as recent satellite images from NASA have shown that the island has begun to fade back into the ocean.
1. Earthquakes Caused By Humans
Our influence on the planet reaches far beyond the air, land, and sea; it penetrates deep into the Earth’s crust, where its vulnerability is most apparent. While earthquakes are naturally triggered by the movement of tectonic plates, human activities can also induce earthquakes of varying magnitudes.
One major human-induced cause of earthquakes is the injection of fluids—such as water or oil—into the ground for industrial or environmental purposes. This process increases underground pore pressure, which can weaken nearby faults. When the pore pressure exceeds a certain threshold, the fault can slip, releasing tectonic stress in the form of an earthquake.
Another human-induced cause of earthquakes is the extraction of groundwater, which scientists believe was responsible for the catastrophic 2011 Lorca earthquake. The quake was triggered by the removal of large amounts of water from the ground to meet the town's water supply needs. This depletion caused stress changes in the Earth's crust, eventually leading to the earthquake.
