
About earthquake intensity
So I just experienced the Venezuela earthquakes and of course I went to check on how bad it “felt” compared to other historical earthquakes.. Went down the rabbit hole of MMI scale and how it’s somehow related to PGA and PGV. I’m confused, not an expert at all so I was hoping some earthquake knowledgeable people would help
USGS slapped La Guaira with a big 7-8.5 MMI sticker after the 7.5 magnitude earthquake. You see that video where people got knocked off their feet and that one suv almost flipped over from the shaking? Yeah that’s like an 8.2, somehow. And apparently, according to USGS, the shaking was worse in the epicenter (Yaracuy)…where the buildings suffered much, much less damage. And it’s not like construction quality is a big factor here.
Also surprised me to see that PGA value for the 7.5 was reported to be like 0.5g. I know it’s an estimation but 0.5? Really? This is 1.5+ footage btw. Look much different to you?
It just seems like everything is lowballed… Or maybe it’s just me trying to make a bigger deal to feel like I went through worse. Or maybe the two earthquakes actually went through each other in some way? Is that even possible?
You can see in a lot of the La Guaira earthquake footage (including the one I shared before) that there was a big 5-7 second jolt. Some insanely violent sweeping motion from the floor. Why? Why did it become so much worse for such a short time, apparently without reason?
Did the two waves like… Synchronize and overlap or something? Why is USGS giving out these kinds of measurements? I mean, of course they’re more knowledgeable than some random on the internet looking at footage, but really… a lot of what they’re putting out seems not that accurate when compared to what happened IRL
Call me crazy, but to me the 2018 Sulawesi earthquake (footage) looks much more similar to the 2026 Venezuela Earthquakes… But the Sulawesi one had an MMI of X and 1.5g PGA.
I don’t know. Of course I’m not an expert and I’m just talking out of a few wikipedia reads… So, what do actually knowledgeable people think about this?