For those who haven't heard, there was a major earthquake in Turkey last night. Effects were felt in countries like Syria, Lebanon, Israel, Palestine and Iraq. There are reports of soccer players trapped in the rubble. This will require a major response.
Technically, the primary and an aftershock. But there really were 2. One a 7.8 and the other a 7.5. Preliminary, of course.
I read something that the second one wasn’t technically an after shock, it was another full on earthquake (not sure what, if any, difference it makes)
Mostly semantic, to be honest. An aftershock is just an earthquake that happens in the same area of a larger earthquake, or mainshock. There is also something called "foreshock" which is smaller earthquake that happen before a mainshock. Not only that, but which earthquake is the mainshock can change if an aftershock is larger than the previous mainshock. So, long story made slightly less long, foreshock, mainshock, and aftershock are all earthquakes that are related to each other and it is determined by which earthquake has the highest magnitude. So, in the case of a 7.8 earthquake and a 7.5 earthquake that happen in the same area, the 7.8 earthquake is the Mainshock and the 7.5 earthquake is the Aftershock. However, if a 7.9 earthquake happens in the coming days/weeks/months, then that 7.9 earthquake would become the mainshock and the 7.8 and 7.5 would become Foreshocks. Clear as mud?
Having grown up in CA, and being in a home of nerds, I learned it makes a big difference...geologically speaking. There is the common mention of an "epicenter," but that is really misleading. And earthquake is a movement along plate boundaries for several kilometers (could be up to hundreds). Aftershocks are the resulting settling of the new locations of the plates. Aftershocks usually last several days, but can occur months later. An "aftershock" not at the same location of the original quake would be considered separate as there would be a different line-of-movement along the plate boundaries. The key point is the location, not the time. A quick note about the epicenter as a single point being misleading. When the is a slippage between to plates, the line-of-movement creates several points where the waves are sent out. As they go out, they cross. (Think of how throwing several smaller rocks into a pond at the same time each causes their own waves.) When those waves cross is where the most violent damage usually occurs. That is why you can find small areas which have significant damage in an otherwise fairly undamaged location. edit - didn't want to get into foreshocks as they don't currently apply.
American coverage of Turkey earthquake, breakdown: - 10% reporting on extent of devastation, ~10,000 deaths and extent of humanitarian crisis. - 90% reporting on the 5 people rescued from rubble.