Earthquakes are one of the most mysterious and frightening natural disasters. Although we have some idea of when the big ones might happen, the others can seemingly happen from nowhere, bulldozing the cities and the creation of secondary disasters such as FIRES, landslides AND tsunami. Climate change is causing an increase in other natural disasters, such as wildfires and hurricanes. It can do so earthquakes even more common?
The largest and most dangerous type of earthquake is a tectonic earthquake. These earthquakes occur because of plate tectonics, the massive plates of rock that make up the Earth crust and upper mantle. Heat emanating from deep within the planet causes these plates to move moderately half an inch (1.5 centimeters) per year, making them rub against each other. The pressure in those areas builds up until it reaches a breaking point where the plates will suddenly move, releasing energy that causes earthquakes.
Unlike other disasters, it’s almost impossible to predict when earthquakes will occur, making planned evacuations nearly impossible.
Unfortunately, climate change could make earthquakes happen closer together and with more intensity, experts told Live Science. With global warming, glaciers are melting at an increasing rate. When glacial meltwater flows off the land and into the sea, the land beneath it rises, he said John Cassidyan earthquake seismologist at 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 surface and then lets go: The noodle stays down as long as there is pressure from above, but once that pressure is released, it rises again. When that happens, pressure changes can cause previously dormant faults to suddenly pop, triggering earthquakes, Cassidy told Live Science.
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More worrisome than glacial melt earthquakes are those that can be triggered by rising sea levels. As the sea level rises, the pressure under the water at the bottom of the sea also increases, he said Marco Bohnhoff, a geophysicist at the GFZ Helmholtz Center Potsdam and Free University Berlin in Germany. As the water pressure increases, the pressure on the fault lines near the coast will also increase.
“Some earthquakes are late in their seismic cycle,” Bohnhoff told Live Science, including earthquakes predicted to occur nearby. San Francisco AND Los Angeles in the coming decades. “This means that just a small increase in pressure is enough to advance the seismic clock. It can be enough in many places to trigger earthquakes.”
Even if we stopped using it greenhouse gases Now, it would take up to 1,000 years for sea level rise to stop, Bohnhoff added. He predicts that as that time passes, the gaps between large coastal earthquakes will become shorter.
Because this prediction would take centuries to prove, Bohnhoff’s research is based largely on existing models. For example, scientists modeled the rise and fall of 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 uncertain whether rising sea levels would cause enough of a pressure change to make these giant earthquakes happen more quickly, at least within our lifetime. He stressed that when they do happen, climate change will make them more dangerous. Tsunamis caused by earthquakes will reach further inland as sea levels rise. Warmer oceans will lead to increased precipitation, which will increase the risk of earthquake-triggered landslides. Rainfall will also make earthquake shaking more pronounced, as any tremors in wet ground are much more reinforced than on dry land. But again, we won’t know exactly what’s going to happen until it happens, and according to Cassidy there’s still a lot we need to figure out.
“It’s an important topic and I’m sure we’ll see a lot of information come out in the coming months and years,” he said. “But regardless of what we’ve discovered, it’s not good news.”