Chiang Rai hit by three aftershocks in four hours Tuesday

[webfact]

Chiang Rai hit by three aftershocks in four hours



CHIANG RAI: -- The Seismology Bureau of the Thai Meteorological Department reported today that Chiang Rai was hit by three aftershocks Tuesday from 4.00 p.m.- 8.30 p.m. Tuesday night.

The third aftershock of 4.3 magnitude at 8.30 p.m. occurred in Phan district with epicentre at the depth of nine kilometres underground.

The second 1.9 size aftershock was in Mae Lao at 5.57 p.m., and the first of 3.5 magnitude was in Mae Suay district at 4.02 p.m,

There was no report of damages of the three aftershocks, it added.

Source: http://englishnews.thaipbs.or.th/chiang-rai-hit-three-aftershocks-four-hours/


-- Thai PBS 2014-07-16

[Garry]

So when is it officially an earthquake and not an aftershock? What magnitude constitutes a reset of the aftershock news, after aftershock news?

[NanLaew]

I had a look at the USGS earthquake map and the only thing that comes up in the area is a 4.1 located 56km N of Myitkyina, Burma on 2014-06-20 03:13:36 UTC+00:00.

Since the USGS have a bit more experience than some department of the Thai weather bureau on this seismic malarkey, I would assume these recent events are all just aftershocks?

When was the last 'big' one in Chiang Rai? I recall maybe a couple of months back there was one that caused quite a lot of damage?

PS. My internet speed is quite challenged here so possibility that my quake map isn't updating fast enough. Anyone can quote any USGS links to these recent events that the locals have pegged at 3.9 and 4.3?

[toybits]

I believe these quakes are not afterschocks but new events. I believe having small but more frequent quakes is better in the long run. I get scared when there are no quakes because it means pressure is building up - when when that breaks, could mean a bigger quake.

[NanLaew]

Then how come they are not eventing on the USGS's global seismic activity map then? They have the most comprehensive network of seismometers locally (I know because my mate installed them) so where does the Thai Meteorological Department buy it's earthquake measuring stick from?

[Garry]

That's the reason why I'm curious; as to what constitutes a new event? Eg: No activity based on a period of time and / or a certain magnitude threshold?

Edited July 17, 2014 by Garry

[Rotweiler]

It's actually very simple. A "new event" is when someone in Bangkok tells us we have had an earthquake that no one here thinks is important enough to comment on....

That's the reason why I'm curious; as to what constitutes a new event? Eg: No activity based on a period of time and / or a certain magnitude threshold?

[brianmarinus]

http://www.seismology.tmd.go.th/en/local.html

When you open it it say-open at your own risk-its nothing but cookies so just press on it and you get the local earth quakes and after shocks.

Edited July 18, 2014 by brianmarinus

[NanLaew]

Good link thanks! I scrolled around and I think I found the 'big' one; a 5.0 on 12th May? I think that was the one where there was a lot of damage to a white colored 'significant' temple and it was on the front page of the Post and Nation. However, it never showed on the USGS global eventer. I know that the USGS installed the geophones and they are part of the global grid but maybe someone had kicked the plug out in the Bangkok office... or their geophone is broken and they have replaced it with a microphone from the karaoke shop.

I have asked my mate, the former USGS engineer who installed them (and a whole lot of others all over SA Asia and China), to advise.

[villagefarang]

If you go to the USGS website and click on the list of countries which are searchable you will find that Thailand is not listed. What your mate did or did not do is of little significance if their website is not setup to post Thailand data or events.

[brianmarinus]

NanLaew...the big one was at 6,3 - 5.th. of May.

[NanLaew]

If you go to the USGS website and click on the list of countries which are searchable you will find that Thailand is not listed. What your mate did or did not do is of little significance if their website is not setup to post Thailand data or events.

And according to what my mate said last night, you are correct... although I reckon he would be a tad miffed that you consider his job as insignificant; he did it for about 20 years. My comment about someone kicking the plug out would have been correct if there had been a plug in the first place. As he explains it, although it was all USGS kit and people installing it, this was back in the days before the marvels of the internet, microwave links and GSM networks so the Thai network is an autonomous one with no live feeds to anything outside the enchanted kingdom. All pretty analog and not very digital IMHO. I would guess for anyone interested, they could use the USGS's website to report local events and by extrapolation from the networks that are 'live', the USGS may be able to start populating Thailand with colored dots.

It is sort of disappointing that the locals didn't go the extra half mile to get globally connected but I understand that the original USGS-installed equipment was the basic system with limited support and no free upgrades.

NanLaew...the big one was at 6,3 - 5.th. of May.

Thanks for that, I should have scrolled another 3 or 4 pages on the link you provided. It certainly is rocking up there.

My curiosity was piqued when a friend of mine had to rush home to Chiang Rai due to the family home being 'broken' in an earthquake earlier this week and I couldn't find any references to recent seismic events.