M 4.8 - Whitehouse Station, New Jersey, US

[Astronuc]

Not a terribly strong earthquake, but it is unusual. It is apparently near the Ramapo fault, whih is part of the Appalachian mountain chain as it curves across NJ into NY and CT.

Folks noticed it - and of course, many panicked and called 9-1-1. I have not heard of any injuries or building damage. Airports in the NY area suspended takeoffs and landing to assess the runways, and bridges and tunnels (between NJ and NY) were briefly closed to traffic to ensure they were not damaged.

My wife, son and I did feel it - a few (4 or 5) seconds of rumbling at the house, almost like a heavy truck (or several) rolling by.

https://earthquake.usgs.gov/earthquakes/eventpage/us7000ma74/executive

M 4.8 - Whitehouse Station, New Jersey Earthquake​

• 2024-04-05 14:23:20 (UTC)
• 40.703°N 74.758°W
• 4.7 km depth

No aftershocks reported, so it appears to be a one-off. It was fairly shallow at 4.7 km. Originally reported at 1 km and 4.8, it was updated to 4.7 Mag, and revised back to 4.8 Mag.

https://earthquake.usgs.gov/earthquakes/eventpage/us7000ma74/region-info

It took about 7 minutes for the USGS site to post information. It was the first place I went for information.

 

[.Scott]

My household in Pelham, NH heard it but did not really feel it. We live directly over an aquifer with wetlands on most sides - so there would have been an amplifying effect
I didn't recognize it (at the time) as a quake and tried to determined what direction it came from - without success.
It lasted for about 30 seconds.

 

[Astronuc]

I didn't recognize it (at the time) as a quake and tried to determined what direction it came from - without success.

My wife wondered if my son was jumping on the floor (he wasn't), I wondered if our heater furnace was having a problem (it wasn't, and it actually wasn't operating until after the quake). Lots of folks started posting on a local Facebook forum, which my wife checks for local news/events. Once USGS posted it's summary, I sent the link to my wife so she could share it.

I've experienced much stronger quakes while visiting California. Ours was much less significant - kind of a light rumble.

https://www.yahoo.com/news/earthquake-felt-42-million-people-160201382.html

 

[.Scott]

My wife wondered if my son was jumping on the floor (he wasn't), I wondered if our heater furnace was having a problem (it wasn't, and it actually wasn't operating until after the quake).

I was in my bedroom with the laundry room one floor below. If the washing machine is unbalanced when it goes into the spin cycle, it can create a rumble that goes on and off similar what I was hearing - so I was trying to determine if that rumble really was coming from the laundry room. But it didn't seem to be and I thought (correctly) that there was nothing in the washer. The mystery was solved half an hour later when I checked my email and saw the news alert.

 

[Baluncore]

We live directly over an aquifer with wetlands on most sides - so there would have been an amplifying effect
I didn't recognize it (at the time) as a quake and tried to determined what direction it came from - without success.

The low velocity material near the surface at your location, not only amplifies the motion, but also refracts the wave, turning the movement upwards, so all quakes will appear to rise steeply from below. That can make identification of direction very confusing and unreliable.

 

[Astronuc]

Apparently there were two aftershocks.

M 3.8 - 7 km SW of Gladstone, New Jersey​

https://earthquake.usgs.gov/earthquakes/eventpage/us7000mab9/executive

• 2024-04-05 21:59:13 (UTC)
• 40.685°N 74.735°W
• 8.5 km depth

Note: The magnitude of this earthquake was improved based on more complete physical modeling. The magnitude was changed from 4.0 to 3.8.

M 2.5 - 7 km WSW of Gladstone, New Jersey​

• 2024-04-06 10:46:39 (UTC)
• 40.694°N 74.744°W
• 9.0 km depth

This small quake is the northern most of the three.


Edit/update: https://www.yahoo.com/news/columbia-university-geologists-head-nj-221739521.html

“We knew right away that it was an earthquake,” said Dr. Folarin Kolawole, a Columbia University geologist. “We were looking at ourselves and started screaming. It was amazing.”

. . .

“The goal is to take measurements of, say, hundreds of fractures that I can see and touch and take measurements on,” said Kolawole.

After scouring the area, even while only having two hours of daylight to work with, their trip was a success.

“We were able to find fractures and fault planes, ancient fault planes, in the bedrock that have similar orientations to the one that ruptured the earthquake,” said Kolawole.

Kolawale said more geologists will be back out in Hunterdon County this week.

 

[Bruzote]

For the record, some of us most definitely were moved by this earthquake. I was in Summit, NJ at my dentist. Despite my reclining in a chair, I felt the building detectably sway (or roll like a particle on the ocean surface?). At first, it was more like truck or construction noise with a strong vibration, but it increased to perceived motion beyond "vibration", affecting balance sensation slightly.