Scivillage.com Casual Discussion Science Forum

(Nov 20, 2017 03:31 AM)Yazata Wrote: [ -> ]Large 7.2 magnitude earthquake in the ocean midway between Vanuatu and New Caledonia in the SW Pacific on Sunday 20 Nov. Tsunami warnings initially issued for both those island groups, but danger has now passed. No tsunami warnings for Australia

http://www.bom.gov.au/tsunami/national.s...lBulletin0

New Caledonia

https://www.voanews.com/a/new-caledonia-...26110.html

note for those not too familiar about Tsunami data & reports.
it is not uncommon for Tsunami measurement to register something, HOWEVER 90% of the time that 'something' is maybe 25cms in height or a harbourmaster observing current & tide changes in a harbour as a result.

so you tend to get 2 reports quite often.
1 saying there is no Tsunami to worry about or no Tsunami which is generally news channels or the public danger alert process...
and the other which are actual scientific reports of the amount of small waves of changes in water behaviour(which is very common compared to actual tsunamis).

soo.. if your wondering why on earth you seem to get soo many reports saying there is and there isnt all at once, thats why.

and the other which is an "Advisory", "Alert" or "Warning"
from the actual Tsunami Warning Centre.
Advisory = something happened & your being told
Alerts = something has happened & waiting for better data before we set off the Big Alarm.
Warning = an actual expectation of potentially life threatening or damaging waves striking somewhere (of varying magnitude)

...

i am quite amazed at the number of quakes in that region.
on the up side its lucky they get quite a few which reduces the chance of something shaking loose easily and casuing major damage.
on the down side, lots of movement.

what i have been pondering about is the arctic.
for thousands of years the arctic has been frozen solid...
now it is starting to melt it will loosen up mountains which may cause undersea land slides when a medium to small quake strikes resulting in sudden never seen before tsunamis the likes of the one which struck some months back.

would be nice to see the science vessels of the various nations start to deploy tsunami bouy's/tidal sensors to start observing the water flows, current, volume, etc etc etc....
the deep water currents around the arctic & antarctic are like the drive shaft on your car while your driving through the middle of the desert.

[my rough estimatation]
if that drive shaft breaks.. the global fish/sea-life potentially will collapse by anywhere around 50%
(= actually millions of people starving to death within a 10 year span after an innitial 5  or so year decline)

crikey !

WWW.GLOBALINCIDENTMAP.COM

Type: EarthQuake
2 hours ago
Magnitude: 6.7
DateTime: 2017-11-30 00:32:52
Region: Central Mid-Atlantic Ridge.
Depth: 16
Source: GeoScience Australia


thats unusually large for that area(does it mean anything in particular? ... well from my observations these quakes here usually come after a bigger one rather than before and do not gget above around 5.7 or soo)
soo does it mean anything specifically... dont know, maybe it is the after effect of all the bigger movemrnts already happened around mexico a month or soo back...


M 6.7 - Central Mid-Atlantic Ridge
I
ShakeMapGREEN
PAGER
Time 2017-11-30 06:32:51 (UTC)
Location 1.108°S 23.418°W
Depth 10.0 km

---

melting ice caps...

this is the type of thing i am wondering about

M 5.6 - Norwegian Sea
I
ShakeMapGREEN
PAGER
Time 2017-11-28 13:15:45 (UTC)
Location 72.596°N 3.251°E
Depth 10.0 km


5.6 is not very big... however
when everything has previousely been frozen solid, things cant shake loose.
when things becomes un-frozen and you have entire mountain sides which can be shaken loose for the 1st time in thousands of years.

exciting for archiologists & geologists... not soo much for the low lying coastal communities which might be subject to tsunamis(dont have to be big to cause damage) the likes of which have never been recorded(for thousands of years).

Please note i am not making a prediction

i am posting this because i really like the japanese moving forward to prepare for such things and using science to put its people 1st.
attempting to learn from the past...


https://www3.nhk.or.jp/nhkworld/en/news/20171219_32/

Quote:A Japanese government panel says a massive earthquake with a magnitude of 8.8 or more could occur off Japan's northern island of Hokkaido.

Such earthquakes have occurred in the area at roughly 350-year intervals. The last one hit 400 years ago, making the next one very likely imminent.

The panel on Tuesday released the estimated scale and probability of quakes that could occur along the Chishima Trench, based on the latest studies. The trench is east and north of Hokkaido.

The panel said the probability of such a quake in the next 30 years is 7 to 40 percent.

Panel chair Naoshi Hirata, a professor at the University of Tokyo's Earthquake Research Institute, warns that an earthquake like the March 2011 temblor off northeastern Japan could be imminent, and that people in eastern Hokkaido should brace for a huge tsunami.

i have not been following the activity lately though i notice we have come into and then out of an activity stage.
we appear to be coming back into an activity stage now.
this 3rd activity stage seems a little closer to the previous 2 than i would expect, but nothing big showing up, just lots of indicator 4.5 plus on pacific rise and a few other places. some very deep movement a month back around indonesia and the on again off again stuff around the solomons.

An earthquake woke me up last night as I was sleeping. I noted the time, then rolled over and went back to sleep.

It didn't feel very strong to me and I estimated it at 3.5-4. The USGS has it at 4.4.

It occurred on the Hayward fault, and its epicenter was just about at the Oakland-Berkeley dividing line. (Maybe 20 miles from my location.)

Here's the USGS report on it:

https://earthquake.usgs.gov/earthquakes/...#executive

Shakemap indicating how strong the shaking was at various locations:

https://earthquake.usgs.gov/earthquakes/...1#shakemap

My house didn't suffer any damage that I'm aware of. The earthquake was felt over a wide area (~200km in diameter) but everyone reports it as feeling pretty puny.

https://earthquake.usgs.gov/earthquakes/...48801#dyfi

I submitted a report on the citizen-science observer report thing on the USGS website.

(Jan 4, 2018 04:05 PM)Yazata Wrote: [ -> ][...] Maybe 20 miles from my location. [...]

Makes a difference. I've slept through even between 4.0 and 5.5-plus magnitude earthquakes that occurred after bedtime, but their focal points were much farther away. A few permanent residents or transient nappers claimed having enough "princess and the pea" sensitivity to have been awoken by them, though.

- - -

Large magnitude 7.9 earthquake in ocean 280 km off Kodiak Alaska last night. No tsunami developed and no tsunami warning currently. This earthquake is large, but the USGS doesn't anticipate that it will cause significant damage because it's so far out at sea. Apparently is was weakly felt along most of the south coast of Alaska.

https://earthquake.usgs.gov/earthquakes/...#executive

(Jan 4, 2018 04:05 PM)Yazata Wrote: [ -> ]My house didn't suffer any damage that I'm aware of.

Actually just the reverse! The earthquake repaired my house!

There was an outside door on my house that was sticking badly so that I had to fight with it every day to open and close it.

After the little earthquake it opens and closes easily and normally. So apparently the door-frame shifted a bit. I don't see any cracks around the corners though where I would expect to see them.

So I'm happy about our little earthquake.

Magnitude 6.4 in Northeast Taiwan.

https://earthquake.usgs.gov/earthquakes/...#executive

http://www.bbc.com/news/world-asia-42966916

It's not a huge earthquake as these things go, but there's dramatic photos of a large building (a hotel, reportedly) tilting crazily and reports of trapped people.

I'm guessing that the hotel had a parking garage at the basement or ground floor level and the building was basically supported by pillars above it. In that kind of construction, the pillars often collapse in earthquakes and the garage-floors pancake.

Relatively small earthquake, notable for its unusual location: Wales, UK. Just north of Swansea. Mag 4.2, felt over a wide area of western Britain.

https://earthquake.usgs.gov/earthquakes/...#executive

Much bigger earthquake, mag 7.2 in southwest Oaxaca Mexico. Felt weakly as far away as Mexico city. This is a relatively remote area, very poor. with small mountain villages. The earthquake is large enough to collapse poorly constructed structures which are probably numerous in this area, so there are likely fatalities. (It's also a dangerous area in which criminal gangs are active. Which suggests that combined with Mexico's endemic disorganization and poor roads, aid might be slow arriving in some of these villages.) USGS models predict between 10 and 100 fatalities. They note that many structures in this area are vulnerable unreinforced adobe brick construction.

https://earthquake.usgs.gov/earthquakes/...#executive

So far the only known fatalities in the Mexico earthquake came when a Mexican military helicopter carrying the Interior Minister and the Governor of Oaxaca state crashed while surveying damage. At least a dozen dead, mostly people on the ground.