Major quake Bougainville PNG ---- NOW

[davenn]

prelim mag M8.0, Bougainville PNG

the P waves were even hitting the stops

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

 

[davenn]

Location map

M 8.0 40km W of Panguna, Papua New Guinea
2017-01-22 04:30:24 (UTC)
153.8 km deep

 

[Astronuc]

USGS reports it as 8.0 - http://earthquake.usgs.gov/earthquakes/eventpage/us10007uph#executive
M 8.0 - 40km W of Panguna, Papua New Guinea
2017-01-22 04:30:24 UTC
Lat 6.267°S, Long 155.119°E
153.8 km depth - very deep
http://earthquake.usgs.gov/earthquakes/eventpage/us10007uph#map

• Panguna, Papua New Guinea (I wonder how much shaking they had?)
  40.9 km (25.4 mi) W
  Population: 2,916
  
• Arawa, Papua New Guinea
  49.6 km (30.8 mi) W
  Population: 40,266

 

[StevieTNZ]

Has been revised down to 7.9. http://www.newshub.co.nz/home/world/2017/01/major-earthquake-rattle-solomon-islands.html

Rather deep, ~154km

 

[davenn]

153.8 km depth - very deep

Has been revised down to 7.9. http://www.newshub.co.nz/home/world/2017/01/major-earthquake-rattle-solomon-islands.html

Rather deep, ~154km

yeah, that meant the max'ing out of my seismo didn't last as long as it would have for a shallower event

• Panguna, Papua New Guinea (I wonder how much shaking they had?)

even at around 150+ km from the event, the shaking would be intense ... many major mining projects on BougainvilleDave

 

[Baluncore]

An earthquake at 154 km is quite deep. Note that this earthquake was 140 km east of the Planet Deep, 29,988 feet (9,140 m), the deepest point in the New Britain Trench, Solomon Sea.

The Planet Deep in the Solomon Sea was found by the German survey vessel SMS Planet in 1912. There was another eponymous 'Planet' Deep for a while in the Philippine Sea, but later survey vessels found deeper points nearby in the Philippine Trench.

The SMS Planet was scuttled at Yap Is, 7th Oct 1914 to avoid capture by the Japanese in WW1. The Yap Trench is only 35 km from Yap Island. It seems that there was some significant attraction between the SMS Planet and deep trenches.

 

[Astronuc]

I'm wondering what the peak ground acceleration was. I wonder if they have any accelerometers in place at any of the mines.

 

[davenn]

I'm wondering what the peak ground acceleration was. I wonder if they have any accelerometers in place at any of the mines.

looks like it got up around 80% of g

 

[davenn]

raw seismogram screenshot off my system, just before it started to overwrite the previous line

Processed file

cheers
Dave

 

[fresh_42]

Oops, I mean wow! Is the tsunami warning still active? Or has there been one. $0.8 \,g$ sounded a lot.

 

[davenn]

Oops, I mean wow! Is the tsunami warning still active? Or has there been one

there was an alert put out, but was canceled after it was found that there were no significant waves generated

0.8 g sounded a lot.

pretty significant, but by no means the largest
exceeding 1g happens periodically with larger events, M6 and up ... lots of factors come into play, type of fault motion, ground type
to name a couple.
The M 6.3 quake that wrecked Christchurch, NZ in Feb. 2011 had a peak ground accel. of 220.3% g pretty much above the focus.
there was a soft ground location some 10 km to the north ( just east of the city centre) that hit 188.7% g

pretty serious recordings for a moderate event

Dave

 

[Astronuc]

The M 6.3 quake that wrecked Christchurch, NZ in Feb. 2011 had a peak ground accel. of 220.3% g pretty much above the focus.
there was a soft ground location some 10 km to the north ( just east of the city centre) that hit 188.7% g

On the other hand, that moderate quake was shallow, at a depth of 5 km (3.1 mi).

The Great Tohoku earthquake of March 2011 had PGA of ~3.0 g
More on PGA - https://en.wikipedia.org/wiki/Peak_ground_acceleration

 

[davenn]

On the other hand, that moderate quake was shallow, at a depth of 5 km (3.1 mi).

indeed ... makes a big difference
another in the list of the many factors that affect ground motion

 

[Mono Kakata]

Astronuc, there are no operating mines on Bougainville at this time (nor since the late 1980s). I have reports from a few places along the west coast -- landslides, some houses knocked down, but so far no reports of fatalities. Also, the place Panguna hardly exists anymore. It references the copper mine there, which is no longer in operation.

 

[davenn]

there are no operating mines on Bougainville at this time (nor since the late 1980s).

I didn't realize that

it made for some interesting history reading

 

[Mono Kakata]

davenn - yes, it does. It's a complex and sad tale. I worked as an anthropologist on Bougainville (west central, among the people called Nagovisi) in the late 1960s and into the early 1970s. At that time, the Panguna mine was in operation, and although it wasn't the only cause of the long and deadly war of secession, it certainly played a major role. I was last there in 2001, after the fighting died down.