|In just two weeks last October, the island of Mindanao in the Philippines suffered from three successive strong earthquakes. The first had a magnitude of 6.3 followed by a magnitude 6.6 and the third, a magnitude 6.5 / Photo by: Teemu Väisänen via Wikimedia Commons|
In just two weeks last October, the island of Mindanao in the Philippines suffered from three successive strong earthquakes. The first had a magnitude of 6.3 followed by a magnitude 6.6 and the third, a magnitude 6.5. While the region has been hit by at least 35 earthquakes since the 1900s, the Philippine Institute of Volcanology and Seismology (Phivolcs) reported that the recent events were unusual.
However, this particular series of strong earthquakes can be explained by the fact that Central Mindanao is one of the most seismically active regions in the country because of the presence of several active faults in the area.
As a result of these massive quakes, at least 22 people died and P1 billion ($19,806,500) worth of damage in the region. Forbes, a global media company focusing on business, investing, technology, entrepreneurship, leadership, and lifestyle, reported that more than 1,200 homes and 10 schools have were destroyed, with many other buildings sustaining significant damage from the shaking.
While this news seems common, the fact remains that earthquakes are becoming stronger and more rampant. In August 2018, several strong earthquakes occurred across the globe. Live Science, a science news website that features groundbreaking developments in science, space, technology, health, the environment, our culture, and history, reported that eight earthquakes that were magnitude 6.5 or greater were recorded in just three weeks during that period. According to the US Geological Survey (USGS), the majority of these earthquakes happened around the Ring of Fire or the Circum-Pacific Belt where about 90 percent of the world's earthquakes occur.
Triggered by Humans?
While the most common cause of earthquakes is the plate boundaries colliding or grinding against each other, recent reports showed that humans are also causing them. Scientists discovered that earthquakes can be caused by the extraction of mining products, groundwater, or oil. Removal of material changes the stress, which can cause faults to move. According to EarthDate, a public service radio program with a mission to engage listeners in earth science and reconnect them to the wonders of their world, more than 50 percent of anthropogenic seismic events are attributed to mining or extraction of groundwater, oil, and gas.
Unfortunately, today’s earthquakes caused by humans occur on a much greater scale. Many industrial activities, particularly mining, have induced earthquakes large enough to cause significant damage and death. Some of these include geothermal energy production, extraction of oil and gas, and filling of water reservoirs behind dams. Worse, industrial activities can even induce extremely large, damaging events across the world.
In 2016, a group of researchers from Durham and Newcastle Universities funded by the Dutch oil and gas company Nederlandse Aardolie Maatschappij developed the Human-Induced Earthquake Database (HiQuake) to review the full global extent of induced earthquakes. HiQuake, considered the world's most complete database of earthquake sequences, was created after the researchers analyzed peer-reviewed literature, media articles, academic presentations, and industry and government reports that show human activity as the cause of an earthquake sequence.
|Scientists discovered that earthquakes can be caused by the extraction of mining products, groundwater, or oil. Removal of material changes the stress, which can cause faults to move / Photo by: Olav Gjerstad via Wikimedia Commons|
Science Daily, an American website that aggregates press releases and publishes lightly edited press releases about science, reported that the data gathered dates back almost 150 years, with most maximum observed magnitude earthquakes falling between magnitude 3 and 4. Miles Wilson, a geophysicist at Durham University working on the HiQuake research effort, stated that they discovered that the most commonly reported causes of induced earthquakes are mining projects (37 percent) and water impounded behind dams (23 percent).
Aside from those, the researchers also showed other causes such as unconventional oil and gas extraction projects using hydraulic fracturing. This comes as no surprise since the number of hydraulically fractured boreholes has increased in recent years. "The more important trend is that between hydraulically fractured boreholes and unusually large earthquakes, most likely related to the reactivation of pre-existing geological faults,” Wilson said.
The findings also revealed that anthropogenic projects, including nuclear explosions and the building of heavy skyscrapers, are also behind these earthquakes. Wilson stated that this is because these activities influence forces acting on the Earth's crust. This can worsen as more projects involving geothermal sources of energy and carbon dioxide emissions become widespread.
In the last 30 years, the five deadliest earthquakes that occurred in Haiti, China, Pakistan, Iran, and the Indian Ocean caused the deaths of 680,000 people. In 2008, an estimated 80,000 people died or went missing following a 7.9 earthquake in China’s Sichuan Province. The worst earthquake on record was believed to have killed 830,000 people in the Shaanxi province of China in 1556.
These figures only prove how earthquakes can be deadly. Reports showed that earthquakes kill more people in developing nations because of two reasons: poor building practices and proximity to fault lines.
Experts say we can’t accurately predict when earthquakes will happen, which means we must always be ready. According to USGS, people should prepare emergency supplies such as a first-aid kit, medications, and a fire extinguisher. But above all, it’s important that factors that cause the worsening of earthquakes must be solved.
|In the last 30 years, the five deadliest earthquakes that occurred in Haiti, China, Pakistan, Iran, and the Indian Ocean caused the deaths of 680,000 people / Photo by: United Nations Development Programme via Wikimedia Commons|