The consequences of the earthquake can shake Turkey and Syria for months and even years

Early Monday morning magnitude 7.8 earthquake broke through Turkey and Syria, and nine hours later followed 7.5 aftershock. The death toll is worth over 3800and rescuers had just begun combing the collapsed buildings.

Aftershocks will continue to rock the area as local faults adjust to such a strong initial shock, and scientists say the process could go on for months or even years, not just days. There is even a possibility, albeit a small one, of an aftershock. more than the original earthquake.

“The risk of aftershocks is, in fact, greatest immediately after the mainshock, but after this earthquake there will be noticeable aftershocks for many years,” says David Oglesby, a geophysicist at the University of California at Riverside. “Right now, I can predict for you that there will be many more aftershocks of magnitude 5, possibly 6 or so in this area. It’s easy to do because historically and statistically it’s almost guaranteed.”

This will turn the humanitarian crisis in Turkey and Syria into something even worse. “We cannot tell people: Okay, you’re done. It was terrible and now it’s over. Because the Earth is arranged differently,” says seismologist Wendy Bohon. “It just sucks to know that these people will have to be shaken by earthquakes for a long time after they were so traumatized and had such a devastating experience.”

Earthquakes are products of plate tectonics: plates are large masses of rock that move independently in the earth’s crust but are in contact with each other along faults. “Eventually, the stress and stress will overcome the friction holding the stones together, and those stones will break in an earthquake,” says Bohon. “When rocks break, they release energy in the form of waves, and those waves are what we experience as shaking.”

On Monday morning, the main shock struck about 125 miles of the East Anatolian Fault, a well-known fault line in southern Turkey. In particular, it was a “shear” earthquake, that is, the stress that occurs between two rock masses moving horizontally until a fault breaks. It was also very shallow underground, meaning that there were stronger shaking at the surface. (The San Andreas Fault in California is also a strike-slip fault—it was the one that actually destroyed San Francisco in 1906.)

Generally speaking, the stronger the main shock, the stronger the aftershocks, the frequency and strength of which tend to decrease over time. As you can see in this map, aftershocks of varying intensity accumulated along the fault line of the original quake, as well as on another but related fault line to the north, where a magnitude 7.5 aftershock appears to have occurred. “It’s a really complex fault system because the crust is really fractured,” says Alice Gabriel, a seismologist at the Scripps Oceanographic Institution.

This complexity means that what happens in one error doesn’t stay there. Perhaps the stress that led to the 7.5 quake had been building up for some time, and the shock from the main shock caused it. “He kind of moved his clock a little bit, so there was a big earthquake that should have happened anyway, probably a little earlier,” says Austin Elliott, an earthquake geologist with the US Geological Survey. Such aftershocks are “just other earthquakes—nothing separates them from one another. It’s just that an earthquake so strong changes the stress in the earth’s crust so significantly that it increases the speed of all other local earthquakes.