What could be the strongest earthquake on the planet, and what is the chance of its occurrence
Not always the high magnitude of earthquakes is associated with their lethality. How to understand the mechanism of this phenomenon, and what kind of “shaking” awaits us in the future, reports LiveScience.
On May 22, 1960, a devastating earthquake struck southern Chile. For 10 minutes, the ground shook so violently that people could not keep their feet. Cracks formed in the roads and buildings collapsed. One survivor of the earthquake and the tsunami that followed said he initially thought the Cold War had escalated into nuclear Armageddon.
The Valdivia earthquake, named after the nearest city to its epicenter, had a magnitude of approximately 9,5 and was the strongest ever recorded before or since. But can earthquakes intensify?
On the subject: Return youth: scientists have discovered a way to restore the previous color of gray hair
Geologists say yes. However, the chances of a much larger earthquake are slim. Although an earthquake of magnitude greater than 9,5 could occur, it would require a fault movement both extremely deep and unusually long to destroy a huge piece of the earth's crust at the same time. There aren't many places on Earth where this could happen, says Wendy Bohon, an earthquake geologist. Bohon said a magnitude 9,5 quake is likely near the upper limit of what the planet could produce, with a magnitude 10 extremely unlikely.
"It's great for Hollywood, but thank God it's not realistic for Earth," Bohon said.
Magnitude is a measure of the amount of energy released during an earthquake. This is slightly different than how strong an earthquake feels, which can be affected by distance from the epicenter and ground conditions. According to Bohon, the same earthquake will be felt more strongly for someone standing on loose soil and sand than for someone standing on solid rock.
The magnitude of an earthquake depends on the total area of the rupture. This, in turn, depends on how deep the fault goes into the earth's crust and how long horizontally the segment that breaks. There are physical limits to how large an area can collapse. The deepest faults are found in subduction zones, where one tectonic plate pushes another. While earthquakes can sometimes occur up to 800 miles (XNUMX kilometers) below the Earth's surface, according to the US Geological Survey, most deep earthquakes do not cause large shaking at the surface. It is those that are in the upper tens of kilometers of the earth's crust that are most dangerous to people.
According to Heidi Houston, an earthquake geologist at the University of Southern California, faults in subduction zones are more likely to trigger large destructive earthquakes. These "falling" faults, so named because they are at an oblique angle rather than vertically, have the largest areas of rocks that can get stuck in each other, build up stress, and then finally collapse.
“In fact, the size of the dipping fault plane is the biggest factor that determines the maximum size of an earthquake, and these fault planes can increase in the subduction zone,” Houston said.
Like the article? Support ForumDaily!(I.e.
But there are also limits on the length of a segment that can break. Even subduction zone faults don't collapse immediately, Bohon says. Usually, something gets in the way—perhaps a seamount, a change in rock type or rock geometry that makes one segment of the fault more resistant to stress than its neighbor.
Another factor that influences the magnitude of an earthquake is how much the fault shifts or shifts, Houston said. The 1960 Chile earthquake actually expanded the country because of the way the land stretched, Sergio Barrientos, a University of Chile seismologist who survived the quake, said in 2016.
Understanding the magnitude
The earthquake magnitude scale can inadvertently obscure the difference between very strong earthquakes. The scale is not linear, but logarithmic: for every unit increase in movement, the ground increases mobility by a factor of 10, and the energy released increases by a factor of 32. Bohon likes to use the metaphor of breaking a pack of spaghetti. If breaking one stick of spaghetti is the equivalent of a magnitude 5 earthquake, you would have to break 32 sticks to release the energy of a magnitude 6 earthquake. On this spaghetti scale, a value of 7 corresponds to a break of 1024 shelves, a value of 8 corresponds to 32 sticks, and a value of 768 corresponds to 9.
As this example shows, the difference between magnitude 8 and magnitude 9 earthquakes in terms of released energy is much larger than the difference between a magnitude 5 and magnitude 6 earthquake. fault than for magnitude 9,5 to 9,6.
Due to measurement uncertainty, there is still scientific debate about whether Chile's 1960 earthquake was a magnitude 9,5, Houston said. But to get across the huge differences in the size of seemingly small numbers at this end of the magnitude scale, a magnitude 9,5 quake is more than twice as strong as the next strongest quake ever recorded, a magnitude 9,2, which happened in Alaska at Prince William Sound in 1964.
There are, of course, planetary catastrophes that could theoretically lead to much larger earthquakes: for example, a collision with an asteroid. Some scientists believe that the asteroid impact that wiped out the dinosaurs 66 million years ago caused earthquakes with double-digit magnitudes, although the exact size is difficult to determine. On a time scale of billions of years, the Earth could certainly witness such a catastrophe, Houston said. But the chances of something more than 9 points happening in a human lifetime is very small, she added. According to 2022 studies, the largest ancient earthquake that was estimated based on geological data also occurred in Chile about 3800 years ago and probably also had a magnitude of about 9,5.
You may be interested in: top New York news, stories of our immigrants, and helpful tips about life in the Big Apple - read it all on ForumDaily New Y.
And size isn't always the most important factor in how deadly an earthquake is, at least not to humans, Bohon said. Small earthquakes have caused many deaths simply because they hit populated areas and areas with buildings prone to collapse. While a magnitude 9,5 earthquake in Chile killed about 2000 people, an estimated magnitude 8 earthquake is believed to have killed about 830 people in Shaanxi, China in 000. And in 1556, a magnitude 2010 earthquake in Haiti killed about 7,0 people. Even the Northridge earthquake in 220, with a magnitude of only 000, which was due to a fault that no one had even noticed before, killed 1994 people, injured thousands and caused billions of dollars in damage because it affected Los Angeles.
“There are so many potential small faults that could lead to devastating earthquakes,” Bohon said. “But people only think about big numbers.”
Read also on ForumDaily:
iPhone Hidden Features: 27 Features You Might Not Know About
Ukrainian clip maker conquers the USA: many stars want a video from a director from Odessa
Abnormal cold weather raged in Afghanistan for several weeks: 166 people died
stdClass Object ([term_id] => 1 [name] => Miscellaneous [taxonomy] => category [slug] => no_theme)Miscellanea
stdClass Object ([term_id] => 8210 [name] => earthquake [taxonomy] => post_tag [slug] => zemletryaseniya)Earthquakes
stdClass Object ([term_id] => 13992 [name] => Likbez [taxonomy] => category [slug] => poleznaja-informatsija)Educational program
stdClass Object ([term_id] => 16499 [name] => magnitude [taxonomy] => post_tag [slug] => magnituda)magnitude
Do you want more important and interesting news about life in the USA and immigration to America? - support us donate! Also subscribe to our page Facebook. Choose the "Display Priority" option and read us first. Also, don't forget to subscribe to our РєР ° РЅР ° Р »РІ Telegram - there are many interesting things. And join thousands of readers ForumDaily Woman и ForumDaily New York - there you will find a lot of interesting and positive information.