East coast geology (older, harder rocks) causes earthquakes to feel about ten times stronger than a west coast earthquake. This is felt roughly the same as a 5.8 in California. That's enough to be notable, especially at a shallow depth.
I'm in Forest Hills (fifth story) and at first I thought it was the usual extreme wind we get because the windows were shaking heavily. Then it got worse and I realized what it was when I felt it through the floor.
I've felt at least one other in the last year or two here but my wife in the other room did not. This one was the strongest I've been through though.
> Episodic tremor and slip (ETS) is a seismological phenomenon observed in some subduction zones that is characterized by non-earthquake seismic rumbling, or tremor, and slow slip along the plate interface.
New Jersey is nowhere near a subduction zone, or any plate boundary.
I can't find any source that matches what you're saying. "Tremor" seems to always be defined in terms of earthquakes, either as a synonym or a "very small earthquake", which wouldn't even apply here because this was relatively large and clearly perceptible to the average person.
As someone who lived for decades in a seismic country, I’d say that tremors can also be perceived. The difference lies mostly in the damage generated by the event.
I felt it in Mass -- I was working on the second floor. My wife was on the ground floor and didn't feel it. From our internal slack channel, this seems fairly common -- people on the ground floor don't feel it here in MA, but higher floors, they do feel it.
Im on ground floor and definitely felt it. In brooklyn. All the buildings around me were visibly shaking. Felt like a freight train going by 10 feet away, but eerily quiet.
This was my second minor quake that could be felt in Mass. I was driving both times. First time I thought my steering felt suddenly rubbery. I was in a rotary. Didn't notice this one.
That was eerie! I felt my apartment building start to rock and sway as the walls were creaking. Not something I’m used to as a NY native, and not something I loved to experience 20+ floors above the ground.
I was in the one in Seattle around 2000 on the 5th floor of a building, and I distinctly remember walking down the hall with the building swaying like a boat in a storm, wondering when the whole thing was just going to snap and crumble into a pile of rubble. Luckily it turns out they make modern buildings not do that. I've been back to that building and they still have cracks in the stairwell from it, though.
On the 38th floor in Hell's Kitchen, I felt my chair and desk shake. It was like 10 seconds long.
One of my neighbours often close their doors with force which causes the wall to vibrate. Then I noticed things not attached to the walls also were shaking and understood it's an earthquake. I also noticed lots of birds flying near the Hudson River. I have never thought I would feel an earthquake here.
I also searched Google to see if there's an earthquake, and at 10:23am nothing was showing up. I remember a year ago Google used to ask "Have you felt your building start shaking", and nothing this time.
I was at a coffee shop in Astoria and it sounded like the subway running under. My first thought was that there is no line under this street (been living here forever). Then I thought maybe a jet liner flew over too close. But then judging by other people's reaction, I realized that this was an earthquake. I had no idea that you can hear earthquakes...
I experienced a 3.8 (I think) in Dallas some years ago, 30 stories up. It was likely caused by oil drilling action in the area, as Texas is not an earthquake zone if I remember correctly. It was not fun, no dampers in that building.
Pretty common, but small and rarely noticed [0]. Probably lots of construction and geotechnical engineering wouldn't have survived anything significant at least in the Northeast
I think i remember someone telling me when i was living in nyc that your area foundations are a lot of clay. That would probably amplify the sensation of a quake.
I experienced a 4.8 earthquake about a month ago in Tokyo, and noticed the shaking significantly. In Manhattan this morning, I didn't notice the 4.7 earthquake at all.
The Belden quake is 4.4 at 7.8 km, and 4.2 at 5 km.
It's a log scale so the Whitehouse quake is much larger, but the significance of the quake seems to be more than just these numbers because Belden quake is irrelevant (didn't make the news really).
Sarupathar was a 5.8 (huge comparatively) at 10 km. Hualien was 5.1 at 15.9 km and talked about more than Sarupathar. So the defining aspect appears to be how many people are within range of the epicenter rather than just raw depth and magnitude. Which makes sense, I suppose. We care about how population centers encounter the movement!
Thank you! Yeah, a 7.4 is humongous. I did wonder about this because my wife's family reported quite intensive shaking and I've been in a 6-something before and that was quite disruptive. I can't imagine a 5.1 being that much.
Well tuned 3d printers are somewhat surprisingly mostly unaffected by earthquakes. People have even done stuff like hanging a printer and printing without any significant issue. It'd just show as a slight imperfection on that specific line.
Makes sense, as long as the force creating the vibration is acting on both the extruder and the bed so they don't move relative to one another it shouldn't really matter.
Was on a call with my boss reluctantly explaining how kubernetes works. I felt the rumble, thinking it was just my discomfort with the state of affairs in my company. Might as well have been a fart in the wind.
A number of years ago, in SoCal (where earthquakes are nothing too special), we had a similar sized quake (maybe a tad bigger). One guy from Denver was out and his eyes went big and wasn't sure what to do -- everyone else just kept talking and moved away from the big glass windows haha.
For my first quake in CA, I was peeing. (I'm a man and I pee standing up.) The shower doors next to me started to rattle, so I thought the people above me were jumping around. I didn't realize it was a quake! (The stream kept going where it was supposed to go.)
I came out of the bathroom and my roommate was terrified.
It was even funnier when my mom called me in a panic and I told her what happened.
Yes, the speed of sound (through the earth, so faster than the speed of sound in air); yes.
In California, typically usgs has earthquakes posted before I can feel them. They didn't have this one a few minutes after I felt it, so I feel like automatic earthquake detection is off in this area of the US.
Same experience -- felt a shaking; thought maybe a heavy truck had passed by for a second, then saw that all the monitors were swaying. Checked USGS and saw nothing, so figured it was nothing, because on the west coast they have the reports up lickety split. Half hour later everyone's phone started buzzing with the automated alert.
We felt it at 10:26 am ET. And an alert was sent to everyone at 11:24 am that an earthquake is coming. And then another one alerting for possibility of aftershocks. No aftershocks felt.
Same thing happened to me. I was on a facetime with someone in Brooklyn, but I was a 2 hour drive north outside of NYC and it took what felt like 30 seconds to propagate over that 200km.
Earthquakes propagate very slowly (around 2-8 miles/sec). That's how systems like ShakeAlert can send out early warning notifications. This one, for example, happened 40+ miles from NYC proper, so residents could have had like 20 seconds notice if the service operated here. People further up or down the coast could have had multiple minutes.
I assume they meant “propagation speed that is substantially slower than light in a vacuum” since that is less than 50ms between any two points on earth.
Sure given the epicenter was in NJ and closer than Brooklyn. I am from Brooklyn, but live in Nyack, NY, and I felt it here. Nyack is 40mi from epicenter, Brooklyn ~60mi. But your experience could be different based on the structure you are in, floor elevation, and existing soil and ground conditions.
Yes. Last time there was a fairly large one in the SF Bay Area I happened to be on the phone with some relatives about 40 miles away and I felt an earthquake a moment before they did.
Earthquake waves have several propagation speeds, because there are different types of waves. The fastest is called the P-wave, which is a compressional (longitudinal) wave, similar to a sound wave, with a velocity of ~5-8 km/s for typical continental bedrock. The second fastest is the S-wave, or shear wave, which is about 65% of the P-wave speed. These waves produce relatively little displacement at the surface (except for close to the epicenter of large earthquakes) but are important seismologically. Then, there are the surface waves, which are caused by the interaction of the S-waves with the surface (in a way that I don't 100% understand). These travel about 90% of the S-wave speed, but they have the biggest displacements at the surface and therefore are the main ones that you feel and that cause damage.
The surface wave displacements also get amplified in wet or loose soil, so the ground shaking and seismic damage is also much greater areas on top of sediment rather than bedrock. Areas on a river, lake or coast where the land has been extended into the water by dumping fill dirt are the worst--ground shaking is really bad and they are very prone to liquefaction.
The difference between the arrival times (at any given point on earth) of the different phases of seismic waves is a function of the distance from the earthquake itself (the hypocenter) and the observation site. It is close to linear in Euclidian distance relatively near the earthquake hypocenter, but becomes more nonlinear farther from the earthquake, because the wave speeds are faster at depth (denser rock) so the travel paths of the wave fronts (the ray paths) are nonlinear. These differences in arrival times are one of the main ways of locating the hypocenter of an earthquake given observations from seismometers at multiple sites. It's essentially triangulation, except with time differences instead of angles--this is done through solving a system of equations.
Additionally, S-waves can't pass through liquids, so there is the 'S-wave shadow zone' that occupies a large fraction of the side of the earth opposite an earthquake where there are no primary S-wave arrivals--S-waves are blocked by the liquid outer core. This is how we found out that the outer core is liquid!
I was laying in bed and thought I'd sleep a little bit more. the earthquake wasn't violent, but certainly noticeable. It was similar to someone walking on my roof, without the banging.
I distinctly remember the first time I created a Twitter account (& probably became aware of Twitter being a thing) was the day when a similar earthquake was felt in NYC back in 2011...
I remember this earth quake! I missed it lol. I happened to be driving and we got out of the car to see a tv telling us how we got hit with an earth quake and my friend and I looking at one another like "what did we miss". This time I happened to be on the second floor of a small office building. I was about to run out of the building if it started to get worse I wasn't sure it wasn't the building having an issue.
I worked in northern Virginia at the time, fairly close to the epicenter.
Our office building shook violently. A poor woman I worked with was quite panicked, dove under her desk... and admonished me afterward for staying calm?
This is the second quake I've felt in Pennsylvania. The first was in 2011. I was born here and lived here for my whole life except for 4 years when I lived in CA, where I didn't feel any earthquakes.
383 comments
[ 3.3 ms ] story [ 329 ms ] threadLast time something like this happened was 25 years ago…
https://www.usgs.gov/observatories/yvo/news/aftershocks-swar...
https://earthquake.usgs.gov/earthquakes/map/?currentFeatureI...
From this URL: https://earthquake.usgs.gov/earthquakes/eventpage/us7000ma74...https://earthquake.usgs.gov/earthquakes/eventpage/us7000ma7c...
For all our sakes, I hope that’s not the case.
(1)https://earthquake.usgs.gov/earthquakes/eventpage/us7000ma74...
4.7 quake at 1 km depth will shake more at the surface than a 6.0 at 30 km depth
I've felt at least one other in the last year or two here but my wife in the other room did not. This one was the strongest I've been through though.
The Wikipedia article says an ETS event is imperceptible to humans. This was not imperceptible.
Tremendously helpful to the people who felt it? Or to geologists?
New Jersey is nowhere near a subduction zone, or any plate boundary.
TREMOR - NO life or financial loss
EARTHQUAKE - life or financial loss
No further distinction is needed, warranted, or desired.
Full stop.
First thought was it was an earthquake, but then no signs other than that I could feel it in legs.
https://earthquake.usgs.gov/earthquakes/eventpage/us7000ma74...
One of my neighbours often close their doors with force which causes the wall to vibrate. Then I noticed things not attached to the walls also were shaking and understood it's an earthquake. I also noticed lots of birds flying near the Hudson River. I have never thought I would feel an earthquake here.
I also searched Google to see if there's an earthquake, and at 10:23am nothing was showing up. I remember a year ago Google used to ask "Have you felt your building start shaking", and nothing this time.
Watching all the water slosh around as the building swayed was... disconcerting.
Right now in Huntington
https://en.wikipedia.org/wiki/1886_Charleston_earthquake
NYC quake was at shallow depth.
4.7 quake at 1 km depth will shake more at the surface than a 6.0 at 30 km depth
https://earthquake.usgs.gov/earthquakes/map/?currentFeatureI...
The Belden quake is 4.4 at 7.8 km, and 4.2 at 5 km.
It's a log scale so the Whitehouse quake is much larger, but the significance of the quake seems to be more than just these numbers because Belden quake is irrelevant (didn't make the news really).
Sarupathar was a 5.8 (huge comparatively) at 10 km. Hualien was 5.1 at 15.9 km and talked about more than Sarupathar. So the defining aspect appears to be how many people are within range of the epicenter rather than just raw depth and magnitude. Which makes sense, I suppose. We care about how population centers encounter the movement!
That's just an aftershock.
The main quake was three days ago. M 7.4 according to USGS: https://earthquake.usgs.gov/earthquakes/eventpage/us7000m9g4...
So for an earthquake that's almost 1000x as strong, you'd think it'd be talked about more.
I came out of the bathroom and my roommate was terrified.
It was even funnier when my mom called me in a panic and I told her what happened.
Do earthquakes have a propagation speed? Might she have felt it before me?
In California, typically usgs has earthquakes posted before I can feel them. They didn't have this one a few minutes after I felt it, so I feel like automatic earthquake detection is off in this area of the US.
Some industrial equipment shuts down to avoid damage.
https://xkcd.com/723/
https://xkcd.com/723/
But in summary, the speed is slower than light, so yes you can find out through telecom faster than it getting to you.
[0] https://www.google.com/maps/place/40%C2%B040'58.8%22N+74%C2%...
[1] https://www.britannica.com/science/seismic-wave
Surface waves yes, body waves not necessarily. But surface waves are more destructive.
https://earthquake.ca.gov/
Frustrated network architects would disagree!
The surface wave displacements also get amplified in wet or loose soil, so the ground shaking and seismic damage is also much greater areas on top of sediment rather than bedrock. Areas on a river, lake or coast where the land has been extended into the water by dumping fill dirt are the worst--ground shaking is really bad and they are very prone to liquefaction.
The difference between the arrival times (at any given point on earth) of the different phases of seismic waves is a function of the distance from the earthquake itself (the hypocenter) and the observation site. It is close to linear in Euclidian distance relatively near the earthquake hypocenter, but becomes more nonlinear farther from the earthquake, because the wave speeds are faster at depth (denser rock) so the travel paths of the wave fronts (the ray paths) are nonlinear. These differences in arrival times are one of the main ways of locating the hypocenter of an earthquake given observations from seismometers at multiple sites. It's essentially triangulation, except with time differences instead of angles--this is done through solving a system of equations.
Additionally, S-waves can't pass through liquids, so there is the 'S-wave shadow zone' that occupies a large fraction of the side of the earth opposite an earthquake where there are no primary S-wave arrivals--S-waves are blocked by the liquid outer core. This is how we found out that the outer core is liquid!
I’m about 15 miles from the epicenter.
Edit: Here it is. It was the end of August which I consider the Fall cause that's when the Fall semester starts for me ^^ https://en.wikipedia.org/wiki/2011_Virginia_earthquake
Our office building shook violently. A poor woman I worked with was quite panicked, dove under her desk... and admonished me afterward for staying calm?
Of course now I've jinxed myself.