M7.7 Jamaica Quake: Surface Waves Coming Soon

  • Thread starter davenn
  • Start date
In summary: Back arc basin A belt of extensional tectonics is a very common feature behind (back from) a subduction trench. Because of the extensional ( pulling apart) action the crust thins creating a basin and volcanism is the common result, eg the Taupo Volcanic Zone (TVZ) in the North Island of New Zealand and many other places around the world. The back arc basin can be on land or in the ocean depending on how mature the island arc is.Now multiple versions of the above to form a basin with a thinned crust Dave Back arc basin
  • #1
davenn
Science Advisor
Gold Member
2023 Award
9,587
10,208
TL;DR Summary
Jamaica quake
Mw 7.7 quake coming in on my seismograph now

http://www.sydneystormcity.com/seismograms.htm

The surface waves have not arrived yet ( at time of writing this) they will probably max out the display
 
  • Informative
  • Like
Likes fresh_42, Klystron and anorlunda
Earth sciences news on Phys.org
  • #2
Gads, that's big. How close to the island is the epicenter, or is it ON the island?
 
  • Like
Likes davenn
  • #3
phinds said:
Gads, that's big. How close to the island is the epicenter, or is it ON the island?

from the USGS map ...

200128  M7.7 offshr Jamaica.jpg
 
  • Informative
Likes phinds
  • #5
davenn said:
Summary:: Jamaica quake

The surface waves have not arrived yet ...
Yeah, there is always some delay of time on Jamaica ...

1580245868047.png
 
  • Haha
Likes phinds
  • #6
Can't be too serious - hopefully. CNN international still covers the current farce in DC, German news channels have breaking news a) new Corona infections b) Jamaica 7.7 no damages reported so far, and another one has only the usual irrelevant news in the ticker. And @berkeman's link speaks of a possible 3ft (1m) tsunami.
 
  • Like
Likes davenn
  • #7
https://earthquake.usgs.gov/earthquakes/eventpage/us60007idc/executive
Fairly shallow at 10 km.
  • Lucea, Hanover, Jamaica125.9 km (78.2 mi) SSE, Population: 6289
  • Montego Bay, St. James, Jamaica139.1 km (86.5 mi) SE, Population: 82867
  • Niquero, Granma, Cuba140.3 km (87.1 mi) ENE, Population: 18771
I wonder how it relates to the Mag 6.4 earthquake in Puerto Rico. Seems to be same fault system.
https://earthquake.usgs.gov/earthquakes/eventpage/us70006vll/executive
https://www.usgs.gov/news/magnitude-64-earthquake-puerto-rico
 
  • Like
Likes davenn
  • #8
Astronuc said:
I wonder how it relates to the Mag 6.4 earthquake in Puerto Rico. Seems to be same fault system.

Same plate boundary, yes. But there's over 1000km between the 2 events, so kinda like asking if a quake
near Mexico City is related to a quake in Los Angeles.
The Puerto Rico was south of the plate boundary, by some 200km, but the Jamaican event was on the boundary.

The Jamaican event was primarily strike-slip, with a little oblique slip component
The Puerto Rican event was a back arc extensional motion (normal faulting)

so both events had a very different tectonic setting

Dave
 
  • Informative
  • Like
Likes Ophiolite and fresh_42
  • #9
davenn said:
back arc extensional motion
Interesting. Please explain what that means. Or maybe a graphic.
 
  • Like
Likes davenn
  • #10
anorlunda said:
Interesting. Please explain what that means. Or maybe a graphic.

OK ... A belt of extensional tectonics is a very common feature behind (back from) a subduction
trench. Because of the extensional ( pulling apart) action the crust thins creating a basin and volcanism
is the common result, eg the Taupo Volcanic Zone (TVZ) in the North Island of New Zealand and many
other places around the world. The back arc basin can be on land or in the ocean depending on how
mature the island arc is.
di-5584-gns.jpg


in the caldera, you can see the faults that angle inwards from either side. These are the extensional
(normal) faults.

((I had another couple of images to upload, but the forum is on a go-slow again for me and refuses to
upload files I will do so when it starts working properly again)))https://en.wikipedia.org/wiki/Back-arc_basin
 
Last edited:
  • Informative
Likes Klystron, BillTre, berkeman and 2 others
  • #11
A single normal fault
extension (normal) fault.jpg

now multiple versions of the above to form a basin with a thinned crust
basin faulting.jpg

Dave
 
  • Informative
Likes BillTre, berkeman and anorlunda

1. What is the cause of the M7.7 Jamaica Quake?

The M7.7 Jamaica Quake was caused by a strike-slip fault, where two tectonic plates slide horizontally past each other.

2. How large was the earthquake?

The M7.7 Jamaica Quake had a magnitude of 7.7 on the Richter scale, making it a major earthquake.

3. Was there any damage or casualties from the earthquake?

There have been reports of some damage and injuries in the surrounding areas, but the full extent is still being assessed.

4. Are there any aftershocks expected?

It is possible that there may be aftershocks following the M7.7 Jamaica Quake, but the frequency and magnitude cannot be predicted with certainty.

5. How can we prepare for earthquakes like this in the future?

It is important to have emergency plans in place and to practice earthquake safety measures, such as drop, cover, and hold on. It is also important to have earthquake-resistant structures in areas prone to earthquakes.

Similar threads

Replies
2
Views
1K
  • Earth Sciences
Replies
12
Views
2K
  • Earth Sciences
Replies
2
Views
3K
  • Earth Sciences
Replies
2
Views
1K
  • Earth Sciences
Replies
3
Views
2K
  • Earth Sciences
Replies
10
Views
3K
  • Earth Sciences
Replies
14
Views
3K
  • Earth Sciences
Replies
2
Views
2K
  • Earth Sciences
Replies
4
Views
1K
  • Earth Sciences
Replies
2
Views
5K
Back
Top