Earthquakes are one of the most mysterious and terrifying natural disasters. While we have an idea of when the biggest ones might happen, others can seemingly out of nowhere, flatten cities and creating secondary disasters such as to burn, landslides And tsunamis. Climate change is causing an increase in other natural disasters, such as wildfires and hurricanes. So could it be earthquakes also more common?
The largest and most dangerous type of earthquake is the tectonic earthquake. These earthquakes are caused by tectonic plates, the huge slabs of rock that make up the Earth. crust and upper mantleThe heat radiating from deep inside the planet causes these plates to warm on average half an inch (1.5 centimeters) per yearcausing them to grind against each other. The pressure in those areas builds until it reaches a breaking point where the plates suddenly move, releasing energy that causes earthquakes.
Unlike other disasters, it is almost impossible to predict when earthquakes will occur, making planned evacuations virtually impossible.
Unfortunately, climate change could cause earthquakes to occur closer together and with greater intensity, experts told Live Science. Global warming is causing glaciers to melt faster. When melted glacier water flows from land to sea, the land that was beneath it rises, according to John Cassidyan earthquake seismologist with the Geological Survey of Canada and the University of Victoria.
It’s the same principle as when a child pushes a pool noodle under the water’s surface and then lets go: The noodle stays underwater as long as there is pressure from above, but as soon as that pressure is released, it floats back up. When this happens, pressure changes can cause previously dormant faults to suddenly fire, triggering earthquakes, Cassidy told Live Science.
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More worrisome than earthquakes from melting glaciers are earthquakes that can be caused by rising sea levels. As sea levels rise, so does the pressure under the seabed, according to Marco Bohnhoffa geophysicist at GFZ Helmholtz Centre Potsdam and the Free University of Berlin in Germany. As water pressure increases, the pressure on fault lines near the coast will also increase.
“Several earthquakes are in late stages of their seismic cycle,” Bohnhoff told Live Science, including quakes expected near San Francisco And Los Angeles in the coming decades. “That means a small increase in pressure is enough to set the seismic clock forward. It could be enough to trigger earthquakes in many places.”
Even if we were to stop using greenhouse gases Now it would take up to 1,000 years for sea level rise to stop, Bohnhoff added. He predicts that during that time, the interval between major coastal quakes will become shorter.
Because proving this prediction would take centuries, Bohnhoff’s research relies largely on existing models. For example, scientists modeled rises and falls in the water level of the Salton Sea, an inland body of water about 80 miles (130 kilometers) northeast of San Diego, over the past 1,000 years and found that when the lake was full, more earthquakes occurred along the nearby San Andreas Fault.
Cassidy, however, is not sure that rising sea levels would create enough pressure change to make these giant quakes happen any sooner, at least within our lifetime. He stressed that when they do happen, climate change will make them more dangerous. Tsunamis caused by earthquakes will travel farther inland as sea levels rise. Warmer oceans will lead to more rainfall, which will increase the risk of earthquake-induced landslides. Rainfall will also make earthquake shaking more pronounced, because any shaking in wet ground much more reinforced then in dry soil. But again, we won’t know exactly what’s going to happen until it does, and Cassidy says there’s still a lot to figure out.
“It’s an important topic, and I’m sure we’ll see a lot of information about it in the months and years to come,” he said. “But whatever we’ve found out, it’s not good news.”