NJ Earthquake affecting Amtrak and Transit 4/5/2024

[AmtrakBlue]

 

[drdumont]

4.8 Earthquake in Central NJ this morning. I felt it in Phila airport hotel. I am sked to ride the Crescent tomorrow to NOL.
Local radio reports the N.E. Corridor has no delays at this time, but local rail transit authorities including PATCO are reporting lines are halted for inspection. AMTRAK just told a local news outlet that AMTRAK has initiated inspection protocols.
As a veteran of the San Fran quake (I was next to TV truck at Candlestick Park) and of subsequent quakes in the LA basin, when I felt the tremor, I looked my coffee cup, and there was wave action. It's really interesting to feel the intial panic response which occurs until reality sets in, as in "Nowhere To Run".
NYC airports have initiated a Ground Stop, and A "Structural Engineer" has been dispatched to inspect the equipment at the NL stadium, site of Wrestlemania. I'm headed to Atlantic City for an Organ concert. I'll wait a couple of hours until the panic subsides.

 

[jis]

Epicenter was off of SR 527 (Old Turnpike Road) about 2 miles North of I-78, a mile North of Oldwick.

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

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

There have been three related quakes so far as of 12:10pm 2024/04/05

https://earthquake.usgs.gov/earthqu...ude","starttime":"2024-03-06T14:23:20.334Z"}}

 

[BlackDiamond]

My son and daughter in law felt it at their house near Providence RI.

No issues with MBTA or the airports in the Boston area.

 

[west point]

Seems earthquakes travel a long distance in the east. Remember the one that damaged the Washington monument? Also, in colonial times the one in Charleston SC that rang bells in Boston?

 

[jis]

I just realized there was a 3.8 aftershock in the same general area a little east of the original epicenter a little after 5pm. The other aftershocks were all around 2 or less.

 

[AmtrakBlue]

This includes explanation as to why some of us did not feel the earthquake.

It all has to do with the dividing line between the rocky geology of the Piedmont region and the sandy soil of the coastal plain. Wunsch said. The dense granite and other rock that lies under the Piedmont carries energy much better.

NEWARKPOSTONLINE.COM
'The whole place was shaking': New Jersey earthquake felt here in Newark
An earthquake shook the Northeast on Friday morning, with residents across the region, including here in Newark, reporting rumbling in an area where people are unaccustomed to feeling the ground

 

[jis]

Incidentally, the epicenter was apparently along the Ramapo Fault. Ramapo River runs along the valley that roughly marks the location of the fault around the NY/NJ border. The epicenter was further south in Readington. The railway angle to it is that the epicenter of the original and the largest aftershock were around NJTs Gladstone Station and White House Station area.

This includes explanation as to why some of us did not feel the earthquake.



NEWARKPOSTONLINE.COM
'The whole place was shaking': New Jersey earthquake felt here in Newark
An earthquake shook the Northeast on Friday morning, with residents across the region, including here in Newark, reporting rumbling in an area where people are unaccustomed to feeling the ground

Transmission of earthquake waves can be strange. Typically lower frequencies travel further in alluvium than higher frequencies, and lower frequencies are felt much less unless the waves are huge.

During the 2004 Sumatra-Andaman 9.1 earthquake only the very low frequency waves were felt in Kolkata over a thousand miles from the epicenter. The effect was that many of the lakes got emptied out as the water sloshed out of them into surrounding field. There was no damage to buildings but the amplitude was apparently quite large. There was no higher frequencies felt (so no rattling and shaking) as it got completely attenuated by the miles of sediment between the bedrock and the surface in the Ganga - Bramhaputra Delta. I was on a flight from Delhi to Kolkata which landed soon after the event. We were excitedly told that all the water has disappeared from the lakes! Apparently the same thing happened around Dhaka.

 

[Metra Electric Rider]

Incidentally, the epicenter was apparently along the Ramapo Fault. Ramapo River runs along the valley that roughly marks the location of the fault around the NY/NJ border. The epicenter was further south in Readington. The railway angle to it is that the epicenter of the original and the largest aftershock were around NJTs Gladstone Station and White House Station area.


Transmission of earthquake waves can be strange. Typically lower frequencies travel further in alluvium than higher frequencies, and lower frequencies are felt much less unless the waves are huge.

During the 2004 Sumatra-Andaman 9.1 earthquake only the very low frequency waves were felt in Kolkata over a thousand miles from the epicenter. The effect was that many of the lakes got emptied out as the water sloshed out of them into surrounding field. There was no damage to buildings but the amplitude was apparently quite large. There was no higher frequencies felt (so no rattling and shaking) as it got completely attenuated by the miles of sediment between the bedrock and the surface in the Ganga - Bramhaputra Delta. I was on a flight from Delhi to Kolkata which landed soon after the event. We were excitedly told that all the water has disappeared from the lakes! Apparently the same thing happened around Dhaka.

Intriguing; do you have any further links for reading about this? Not finding anything readily.

 

[jis]

Intriguing; do you have any further links for reading about this? Not finding anything readily.

I have never looked, since I was there and saw it with my own eyes. Unlikely that there was any significant report except perhaps in local newspapers since there was no damage or destruction. All the reports from that event are about what happened at the Andaman Islands and the destruction caused by the Tsunami hitting India's Coromandal Coast.We had our house inspected after it and there was no significant damage, just a few minor cracks here and there.

Incidentally this phenomenon has apparently been observed also in conjunction with large earthquakes in the Himalayan belt on the plate boundary too, including the big one in the 19th Century which completely changed the course of the River Bramhaputra.

 

[Metra Electric Rider]

I have never looked, since I was there and saw it with my own eyes. Unlikely that there was any significant report except perhaps in local newspapers since there was no damage or destruction. All the reports from that event are about what happened at the Andaman Islands and the destruction caused by the Tsunami hitting India's Coromandal Coast.We had our house inspected after it and there was no significant damage, just a few minor cracks here and there.

Incidentally this phenomenon has apparently been observed also in conjunction with large earthquakes in the Himalayan belt on the plate boundary too, including the big one in the 19th Century which completely changed the course of the River Bramhaputra.

That's too bad, It's really intriguing - would love to read more about the phenomenon.

 

[jis]

That's too bad, It's really intriguing - would love to read more about the phenomenon.

I found one reference of seiches - i.e. an effect like water sloshing around in a bowl. Typically triggered by the bowl moved around at a relatively low frequency

Seismic Seiches & Other Phenomenon:

This earthquake also caused energetic seismic seiches in water bodies in Assam, Jharkhand, Maharashtra, Manipur, Orissa and West Bengal. In Kolkata, residents of Behala in the south-eastern part of the city describe vigorous seiches in ponds in the area. Seismic seiches were also seen in other parts of Kolkata and also in Balasore in neighbouring Orissa. One person drowned in a pond as a result of a seiche in Nadia, West Bengal. Television news reports also said such instances were common in Bhubaneswar, Balasore, Puri and other townin Orissa. Press reports from Jharkhand also spoke of similar occurrences in Dhanbad and Rajganj. Similar phenomena were observed throughout Bangladesh and at the Maipokhari Lake in eastern Nepal as well as from water bodies in northern Thailand. A seismic seiche was also reported from ponds in the Ganeshpuri temple and from Gorai in Mumbai in Maharashtra. Such seiches were reported from the almost same region in the last great Mw=8.5-8.7 earthquake in Sumatra in 1861.

The full article is here http://asc-india.org/lib/20041226-sumatra.htm

I see contrary to my recollection, some tremor was felt in Kolkata, but again damage if any was minimal. As I said our house did not suffer any damage., Even much more rickety houses than ours withstood whatever was felt.

I was just talking to a friend in Kolkata who is a geologist and he said that apparently seiches are not that uncommon from extremely large earthquakes on plate boundaries in that part of the world, as the plate underneath shifts appreciably as a result of the 8+ earthquake, causing large low frequency waves to propagate out and they travel much further..

Wikipedia has a good article on Seiche:

https://en.wikipedia.org/wiki/Seiche

The seiches around Kolkata in 2004 are mentioned in this article too.

 

[Metra Electric Rider]

I found one reference of seiches - i.e. an effect like water sloshing around in a bowl. Typically triggered by the bowl moved around at a relatively low frequency



The full article is here http://asc-india.org/lib/20041226-sumatra.htm

I see contrary to my recollection, some tremor was felt in Kolkata, but again damage if any was minimal. As I said our house did not suffer any damage., Even much more rickety houses than ours withstood whatever was felt.

I was just talking to a friend in Kolkata who is a geologist and he said that apparently seiches are not that uncommon from extremely large earthquakes on plate boundaries in that part of the world, as the plate underneath shifts appreciably as a result of the 8+ earthquake, causing large low frequency waves to propagate out and they travel much further..

Wikipedia has a good article on Seiche:

https://en.wikipedia.org/wiki/Seiche

The seiches around Kolkata in 2004 are mentioned in this article too.

Yes, Lake Michigan has been affected by seiches - several people died in one back in the, iirc, 50's.