Can It Happen Here?

[Scott]

The big quake that hit China and was felt all in BKK is really a scary scenario. There have been some major aftershocks and then I heard on the news today that Indonesia had a quake. It seems that the tectonic plates and fault lines in this region of the world are somewhat more unsettled than usual. Is BKK (and Thailand in general) at a greater risk of a quake and how much 'shaking' could the buildings take before it would be a major disaster?

Part of what had me thinking about this is that my dog and cats always act strangely when there is a quake--not that they can predict these things, but the other night they were all behaving the same way as they did when the tsunami hit and the same way as the China quake (and a few smaller ones). But this also happens when there is a strange animal in the garden etc. At any rate, I suddenly found myself staring at the ceiling wondering if the whole place might not collapse on me!

What do others know or think?

[britmaveric]

thai construction - I think you better be on the groundfloor or outside when it happens.

[froggshw]

dont think it would take too much shaking to collapse buildings in Thailand...lets hope it never happens

[PhilHarries]

Bangkok is not built on or near a major fault line so the chances of a major seismic event being centered there are minimal to the extreme. There is a minor fault, from memory, located some way to the north that sometimes gives a little rumble but nothing much in terms of the Richter scale. The major tremors felt in Bangkok come from events centered away to the south (Indonesia) and north/northwest (Laos, China etc). Even the worst of these have not, to my knowledge, caused any serious structural damage in Bangkok. They sway a few tall buildings that results in the workers running out screaming which is more of a risk to life and limb than the quake itself.

In terms of risk IMO you can ignore earthquakes except for keeping valuable fragile objects to the back of shelves.

However, never try and predict Mother Earth and always expect the unexpected.

[Scott]

I thought that Kanchanaburi has a fault that is somewhat threatening to BKK area.

[0Mix1up]

I think the big issue for Bangkok, if it were to happen (and I pray it doesn't) is what it was built on.

And condolences to all those in misery in China.

[flying]

I know I have wondered about Thai quality of construction when I saw some construction being done in Puket last year.

But that aside...... I live in Hawaii & the island is still active so we have seen earthquakes over the years.

The worst I rode out was on Nov 16th 1983

6:03am I remember it like yesterday.

Reason is it was 7 points on the Richter scale & lasted 50 some odd seconds.

You know I am a building contractor by trade & what I saw & learned that day was this............If the quake is big enough (anything over 4 on the Richter ) & the duration more than a handful of seconds there is not much mother earth cannot topple if she is pissed off enough

[teacup]

I thought that Kanchanaburi has a fault that is somewhat threatening to BKK area.

You're absolutely correct and Huahin is part of it too, all the way to Chiangmai. Check out the earthquake zone map -the NationalGeographic 2005 - don't remember what month exactly

[Shotime]

I'm in Bangkok, and I felt the earth move last night

[toptuan]

I think the big issue for Bangkok, if it were to happen (and I pray it doesn't) is what it was built on.

Exactly.

The biggest seismic problem Bangkok faces is the sandy fill that has built up over the centuries from the Chao Praya River, creating an ideal liquefaction zone which also devastated the Marina District in San Francisco during the last big earthquake there.

The second biggest seismic problem Bangkok faces is the total lack of seismic reinforcement in 90% of its structures. The tall skyscrapers are probably well-designed, especially with a steel superstructure designed to flex in seismic conditions; however, it's the worrisome multi-story structures eight floors or less which are not able to withstand even a moderate earthquake in this region. Everyone of these is a Chinese school building ready to pancake in such a scenario. The only reason that the San Francisco Marina District did not suffer further destruction was due to a majority of wood construction which tends to flex better in seismic conditions. Unreinforced masonry (which comprises the vast majority of Bangkok's structures) is a disaster just waiting for a big enough jolt.

(Below scans from The Nation following the Sumatran earthquake which preceded the Boxing Day Tsunami.)

Edited May 22, 2008 by toptuan

[Ulysses G.]

We have small ones in Chiang Mai fairly often. How much danger is likely?

[A_Traveller]

I note that an apartment building here in Bangkok had posted 'earthquake' advice notes in the lifts, including cute drawings of people under tables.

Regards

Edited May 22, 2008 by A_Traveller

[toptuan]

We have small ones in Chiang Mai fairly often. How much danger is likely?

Notice on the above seismic zone map, that Chiang Mai is in the same zone as Bangkok, but is in much closer proximity to the "medium risk" zone which includes the Kanchanaburi fault zone.

[TheDon]

I hope nothing happends to Thailand, building in Thailand aint the best but compared to Burma they are solid. I dont think there will be as much death in LOS. Well I hope not anyways

[Ulysses G.]

Since Chiang Mai is built on firm ground, does that mean that we are fairly safe?

[toptuan]

Since Chiang Mai is built on firm ground, does that mean that we are fairly safe?

IMO, the disadvantage of being closer to the Kanchanaburi fault zone and the advantage of firmer ground (depending on how much is built on the overflow sandy loam of the Ping River over the centuries), is probably a "wash."

To personalize the risk a bit, in these more active zones, I would just feel much safer in a one-story dwelling with a metal roof overhead (those falling tiles really can raise a bump on the head!). Keep the bed away from the walls, use two thick mattresses, and jump between them at the Moment of Truth.

Edited May 22, 2008 by toptuan

[toptuan]

I hope nothing happends to Thailand, building in Thailand aint the best but compared to Burma they are solid. I dont think there will be as much death in LOS. Well I hope not anyways

Give me a flexible wood/bamboo structure (housing the majority of Burma's population) any day over a "solid" structure in the event of a "shaker." (Of course, wind resistance is a total 'nother story... )

Masonry structures do have a comfort factor in their "solid" appearance, but are remarkably brittle when it comes to the "shake" factor. Ever watch the karate expert do his thing with 5-8 concrete blocks? The first one only really breaks due to the resistance of the material itself. The rest mostly self-destruct due to the seismic-like "jolt" factor from the blocks above--similar to the "pancake-ing" that happened with the Chinese school buildings--except that the energy source comes from underneath in an earthquake.

I have had extensive training in seismic reinforcement for seismic Zone 6 and 7 regions of the world (Tokyo and USA West Coast), and it always gives me a queazy feeling in the pit of my stomach to watch masonry/concrete building construction in Asia, including Thailand.

The only thing that lets me sleep at night is living in the Isaan "green zone" for seismic activity (although I still have the two thick mattresses readily available ) Oh yeah, and that nightcap.

Edited May 22, 2008 by toptuan

[submaniac]

Man, you folks got me thinking. Anyways, I did a quick google and found this on Thailand's earthquake fault areas. It might be useful.

http://www.dmr.go.th/geohazard/earthquake_...veFault_Eng.htm

[lannarebirth]

You know I am a building contractor by trade & what I saw & learned that day was this............If the quake is big enough (anything over 4 on the Richter ) & the duration more than a handful of seconds there is not much mother earth cannot topple if she is pissed off enough

I'm not sure a cat is even aware of a 4.0 quake.

Chiang Mai has dozens of these tiny magnitude quakes per year. It's not a bad thing, it's a good thing. These little temblors serve to relieve pressure tha tcould lead to quakes of larger magnitude.

[MJo]

thai construction - I think you better be on the groundfloor or outside when it happens.

One of my Taiwanese friends, who's been thru the last big one and several smaller ones, gave me advice that it is actually better to be as high floor as possible if big one hits. His reasoning was that if you survive the initial quake and the collapsing building it is more likely that you will be rescued in case there is only one or two floors of the building on top of you instead of all the 42 and basement car park. Kind of makes sense...

Now i've been trying to tell this to the missus but she still point blankly refuses to stay high floor apartments and want's to move from present 7th floor unit to ground floor to be safe from the quakes...

Any case i doubt that all quakes happen at night when you are home so one can't really prepare for it in place like BKK. Being outside in the street is the worst i guess with all that glass hanging over your head.

Edited May 22, 2008 by MJo

[offset]

This site will tell you a lot about earthquakes www.iris.edu/seismon

[toptuan]

thai construction - I think you better be on the groundfloor or outside when it happens.

Elderly Japanese lady: "Better to be upstairs, when upstairs become downstairs!"

[Heng]

Glad my house is one story and built to my own specifications. Would much rather deal with falling gypsum than pancaking floors.