04-09-2024, 08:37 PM
For the Science Nerds or interested.
Most Earthquakes (EQs) occur on active margins, where you have spreading/extension (mid ocean ridges), compression (Mountains like the Himalaya's) or strike-slip (San Andreas in Cali).
The plates are constantly moving, but they also have a tremendous amount of friction when trying to slide by each other and the usually get stuck. When they "unstick" they move abruptly and you get EQs. Also, the slippage isn't uniform. Some parts of a plate boundary slip constantly, creating little to no build of of potential energy and some are very sticky storing lots of energy and creating large EQs.
New Jersey is on a stable margin, not an active margin, so how did we get EQs and aftershocks there. Because what is now passive was ONCE active. The EQs in NJ originated from a failed "triple junction".
What the heck is a triple junction? (https://en.wikipedia.org/wiki/Triple_junction) When continents have been crashed together and joined by Plate Tectonics, it creates a insulating effect due to the thick continental crust, mantle circulation and no spot to release heat. So the crust heats and heats until magma moves up through the thick crust and bursts out. The shape of this usually has three prongs, thus the name triple junction. With the magma pouring out, it starts to break the continent up, pushing away from the initial area in three different directions. If the process continues then the triple junction will be where three separate tectonic plates meet. A failed triple junction is where the process started, but then did not continue for various reasons. Geology is dumb. The Earth likes the path of least resistance, so when continental breakup happens in history you get lots of failed triple junctions. Though they are no longer moving ACTIVELY, they are still zones of weakness representing rips through the 30-50km thick continental crust that can still build up potential energy, but over much longer periods of time. This is what moved in New Jersey.
Now to scare the shyt out of you, the most famous failed triple junction event in the history of the US happened in the center of the continent in Missouri in 1812 - read this and be terrified because it hasn't moved in 140 years - I give you the New Madrid Seismic Zone - ( https://iemaohs.illinois.gov/preparedness/earthquake-newmadrid.html#:~:text=The%20New%20Madrid%20Seismic%20Zone%20(NMSZ)%20is%20a%20150%2D,western%20Kentucky%20to%20southern%20Illinois. ) and ( https://www.usgs.gov/programs/earthquake-hazards/new-madrid-seismic-zone )
Most Earthquakes (EQs) occur on active margins, where you have spreading/extension (mid ocean ridges), compression (Mountains like the Himalaya's) or strike-slip (San Andreas in Cali).
The plates are constantly moving, but they also have a tremendous amount of friction when trying to slide by each other and the usually get stuck. When they "unstick" they move abruptly and you get EQs. Also, the slippage isn't uniform. Some parts of a plate boundary slip constantly, creating little to no build of of potential energy and some are very sticky storing lots of energy and creating large EQs.
New Jersey is on a stable margin, not an active margin, so how did we get EQs and aftershocks there. Because what is now passive was ONCE active. The EQs in NJ originated from a failed "triple junction".
What the heck is a triple junction? (https://en.wikipedia.org/wiki/Triple_junction) When continents have been crashed together and joined by Plate Tectonics, it creates a insulating effect due to the thick continental crust, mantle circulation and no spot to release heat. So the crust heats and heats until magma moves up through the thick crust and bursts out. The shape of this usually has three prongs, thus the name triple junction. With the magma pouring out, it starts to break the continent up, pushing away from the initial area in three different directions. If the process continues then the triple junction will be where three separate tectonic plates meet. A failed triple junction is where the process started, but then did not continue for various reasons. Geology is dumb. The Earth likes the path of least resistance, so when continental breakup happens in history you get lots of failed triple junctions. Though they are no longer moving ACTIVELY, they are still zones of weakness representing rips through the 30-50km thick continental crust that can still build up potential energy, but over much longer periods of time. This is what moved in New Jersey.
Now to scare the shyt out of you, the most famous failed triple junction event in the history of the US happened in the center of the continent in Missouri in 1812 - read this and be terrified because it hasn't moved in 140 years - I give you the New Madrid Seismic Zone - ( https://iemaohs.illinois.gov/preparedness/earthquake-newmadrid.html#:~:text=The%20New%20Madrid%20Seismic%20Zone%20(NMSZ)%20is%20a%20150%2D,western%20Kentucky%20to%20southern%20Illinois. ) and ( https://www.usgs.gov/programs/earthquake-hazards/new-madrid-seismic-zone )
![[Image: 4CV0TeR.png]](https://i.imgur.com/4CV0TeR.png)
