Why was the DR spared and for how long?

Jan 3, 2003
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I am no expert on temblors so I would like to know WHY and for how long. Someday, the DR will face a similar catastrophe and then what?
 
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ExtremeR

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Mar 22, 2006
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One thing I am observing through the wide variety of photoes of this sad catastrophe is that most of the Haitian structures lacked rebars, I've been trying to find one in every picture but still haven't seen any.
 

Chirimoya

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Dec 9, 2002
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In this particular instance, the location of the epicenter.

Now that such a big one has hit, is it more than wishful thinking to suppose that the tension building up in the tectonic plates was released and it will be a long time before the next?
 

Roark

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Jan 14, 2010
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One thing I am observing through the wide variety of photoes of this sad catastrophe is that most of the Haitian structures lacked rebars, I've been trying to find one in every picture but still haven't seen any.

I have seen reinforcing steel in most of the major downed [concrete] structures. The mass-housing (Earthen-type material and tin roof) obviously does not have this.

Rebar is only as good as the quality of the concrete blocks, mortar and its placement within the concrete structure. If the earth shifts under 2 sections of a home [like at a T], it will most like "tear at the seams".
 

NALs

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Jan 20, 2003
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In this particular instance, the location of the epicenter.

Now that such a big one has hit, is it more than wishful thinking to suppose that the tension building up in the tectonic plates was released and it will be a long time before the next?
The strongest earthquake to have ever hit the island since records have been kept was in the mid-1940s in the DR. That earthquake was over 8.0 in the Ritcher scale.

Plus, the Haiti earthquake was the release of pressure in the southern Enriquillo fault line and in 2003 the other fault line that runs just south of the Cordillera Septentrional in the DR released its pressure. Those are the two big fault lines crossing the island.

So, with that in mind, my guess would be that chances for the next 'big one' will not be any time soon.
 

Adrian Bye

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Jul 7, 2002
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the dr is due for a big one anytime, especially around santiago and the north coast. if we had a 7.3 hit here like PAP did, we'd be a real mess too, just not as bad.

lets just hope it isn't a 9.0 like has happened in other places. if you want to read about a real earthquake, read this first hand account of the lisbon earthquake in 1755 which set portugal on the downward path its on today. it caused the capital city to be moved to brazil (which is rather odd for a european country).

it started with a big quake.. then came a fire which destroyed the city.. so people ran to the water.. then along came a tsunami and drowned a ton of people..

it was devastating.

summary: Historical Depictions of the 1755 Lisbon Earthquake

first hand account: Modern History Sourcebook: Rev. Charles Davy: The Earthquake at Lisbon, 1755
 

Ringo

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Mar 6, 2003
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I am no expert on temblors so I would like to know WHY and for how long. Someday, the DR will face a similar catastrophe and then what?

You ask a question that can not be answered. You ask a question that does not help the Dominican Republic. You ask a question that would not help any part of the World and can not be answerd. It only scares people for the effect of ... a reaction to scare them?

OK... my answer. The Big One has hit our area on our Island and it will be another 200 years before the next. Not true. Again, earthquakes are an unknown and just about every part of the World has them. Some more then others and some don't even notice them.

Being that we lived in the San Franciso Bay area, Ca. for many years and still have family their I have a little background on these things. We were their in 89.
 

Roark

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You ask a question that can not be answered. You ask a question that does not help the Dominican Republic. You ask a question that would not help any part of the World and can not be answerd. It only scares people for the effect of ... a reaction to scare them?

OK... my answer. The Big One has hit our area on our Island and it will be another 200 years before the next. Not true. Again, earthquakes are an unknown and just about every part of the World has them. Some more then others and some don't even notice them.

Being that we lived in the San Franciso Bay area, Ca. for many years and still have family their I have a little background on these things. We were their in 89.

Ummm, O&C is merely posing the question. Ok, no problem. I don't know the qualification of Ringo or O&C, but the seismology of this region is well, well understood by the scientific community.

You are right in that seismic activity is a constant and mostly undetectable without instrumentation, BUT the DR sits smack in the the middle of two major trouble spots (Septentrional and Enriquillo faults) which puts DR is a constant state of tectonic pressure. As they say, it's not IF, it's WHEN.

I don't know what math or science you are using when you say 200 years [O&C or who said?], but I'd like to see it.
 
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Chirimoya

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Dec 9, 2002
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If the epicentre had been 15 kms from Santo Domingo, wouldn't we still have seen massive destruction and casualties?
 

Ken

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Jan 1, 2002
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I don't know what math or science you are using when you say 200 years, but I'd like to see it.

Roark, if you reread Ringo's post again, you will see that he made the statement re 200 years, then immediately followed that with a "Not true."

It was a tongue in cheek response to an unanswerable question.

The Dominican often say, si Dios quiere, meaning, if God wills. That is probably as good as answer as any to the question.
 

CFA123

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May 29, 2004
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multiple fault lines run through or near DR. there are regular quakes of magnitude 3 or less that most people don't feel. less frequent (but not infrequent) quakes of higher magnitude are felt and fairly often reported in the local news.

neic_pwbj_m.jpg


You can see the fault line where pressure was released this week near Port au Prince in green at the lower left.

The green line running through the mountains to the north is where the Sept 22, 2003 6.4 magnitude quake occurred. (centered near Pto Plata)

The purple fault line off the north coast hasn't had a recent significant quake that I'm aware of.
 

Roark

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Jan 14, 2010
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Roark, if you reread Ringo's post again, you will see that he made the statement re 200 years, then immediately followed that with a "Not true."

It was a tongue in cheek response to an unanswerable question.

The Dominican often say, si Dios quiere, meaning, if God wills. That is probably as good as answer as any to the question.

I know, I edited to indicated it was directed at the poster who stated it. Sorry for the confusion, Neptuno :)
 

CFA123

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Last 16 years of seismic activity in the Caribbean... Hispaniola's not even visible due to all the shaking going on. The big 2003 quake in DR wasn't that long ago, but it appears there are many that are caught by surprise that Hispaniola is EQ prone :ermm:

caribbean.gif


and a link to some good information Caribbean Earthquake Information
 

ExtremeR

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Mar 22, 2006
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I have seen reinforcing steel in most of the major downed [concrete] structures. The mass-housing (Earthen-type material and tin roof) obviously does not have this.

Rebar is only as good as the quality of the concrete blocks, mortar and its placement within the concrete structure. If the earth shifts under 2 sections of a home [like at a T], it will most like "tear at the seams".


I'm going trough photos and photos of ruins and still haven't seen the first rebar.
Obviously some of the buildings downed may have some rebars, but not in the quantity I've seen them in the DR for example.

Chip, does a rebar enforced structure hold well in a similar quake? It is feasible for a rebar enforced structure to fall down completely to one side in a quake? Or it will be just cracks in the wall and maybe roof failure?
 

AlterEgo

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Jan 9, 2009
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The strongest earthquake to have ever hit the island since records have been kept was in the mid-1940s in the DR. That earthquake was over 8.0 in the Ritcher scale.

Is that the one that buried a city? I know there's a church that's completely buried except for the steeple - people make pilgrimages there... La Vega?????

There but for the grace of God goes the DR

AE
 

Roark

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Jan 14, 2010
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I'm going trough photos and photos of ruins and still haven't seen the first rebar.
Obviously some of the buildings downed may have some rebars, but not in the quantity I've seen them in the DR for example.

Chip, does a rebar enforced structure hold well in a similar quake? It is feasible for a rebar enforced structure to fall down completely to one side in a quake? Or it will be just cracks in the wall and maybe roof failure?

there are no major structures built without it. Whether you ignored the details in my above post or not, Rebar is only as good as it's architectural placement. It's hard to rebar a seam [T section] EXtremeR. When the earth below shifts, the rebar will absorb the tensile and compressive forces, but only to the extent of proper placement. God doesn't know where you put them.
 

kjdrga

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Mar 25, 2002
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I'm going trough photos and photos of ruins and still haven't seen the first rebar.
Obviously some of the buildings downed may have some rebars, but not in the quantity I've seen them in the DR for example.

Chip, does a rebar enforced structure hold well in a similar quake? It is feasible for a rebar enforced structure to fall down completely to one side in a quake? Or it will be just cracks in the wall and maybe roof failure?

You can see some of the damage with rebar coming out from the ruins in this series of pictures. They are from Carel Pedre (carelpedre) on Twitter

Carel Pedre flickr page carelp's Photostream


kj
 
Jan 3, 2003
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175
63
multiple fault lines run through or near DR. there are regular quakes of magnitude 3 or less that most people don't feel. less frequent (but not infrequent) quakes of higher magnitude are felt and fairly often reported in the local news.

neic_pwbj_m.jpg


You can see the fault line where pressure was released this week near Port au Prince in green at the lower left.

The green line running through the mountains to the north is where the Sept 22, 2003 6.4 magnitude quake occurred. (centered near Pto Plata)

The purple fault line off the north coast hasn't had a recent significant quake that I'm aware of.

For those of us who are neophytes in temblors, the color coded depths relate to the depth of the fault line?

At what point do you begin measuring the depth?

The deeper the depth of the fault line, the greater the damage of the temblor?
 

CFA123

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May 29, 2004
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Onions/Carrots,
Since experiencing the 2003 quake, I've done some research on the internet but am far from educated enough to confidently answer many questions. I 'think' there are many parameters associated with strength of quake - type of fault, type of slip (lateral or vertical), type of ground (sandy or rocky), etc, etc. Honestly, it becomes confusing for me after a while & I've drawn few conclusions.

There does seem to be a consensus that the northernmost faults thru the mountains and offshore have the potential for devastating 7.0+ EQ's.

Another couple of links to help you out in research:
WHOI : Oceanus : Tsunamis in the Caribbean? It's Possible.
Natural Hazards in the Caribbean
10-degree Map Centered at 20?N,70?W
Red S?smica de Puerto Rico