7.7 earthquake in Chile

[southsider2k5]

No reports of damage or injury thus far...

[LosMediasBlancas]

7.7 and little damage ?????!!!.........or has the town been demolished so no one is left to report any damage?

[Rex Kickass]

I don't know that it was in a heavily populated area. The earthquake was in a desert. Calama is the largest city closest to the quake with a population of 140,000 people.

[NorthSideSox72]

Magnitude is one of a few factors that dictate the amount of damage caused. Another key one is depth. This earthquake occured 37 miles beneath the surface - which seems awfully deep to me. But maybe one of our resident scientists can say just how deep that is, relatively.

 

Another factor is terrain. Mountainous areas can often mean the damage dissipates in a much shorter distance around the epicenter. Like transferring force through a pile of bricks, as opposed to a bucket of sand. Because of the gaps and cracks, it dissipates quicker in the bricks, so the damage radius is smaller.

 

[Balta1701]

Link

Magnitude is one of a few factors that dictate the amount of damage caused. Another key one is depth. This earthquake occured 37 miles beneath the surface - which seems awfully deep to me. But maybe one of our resident scientists can say just how deep that is, relatively.

 

Another factor is terrain. Mountainous areas can often mean the damage dissipates in a much shorter distance around the epicenter. Like transferring force through a pile of bricks, as opposed to a bucket of sand. Because of the gaps and cracks, it dissipates quicker in the bricks, so the damage radius is smaller.

See what happens when I don't read every thread? I miss questions for me.

 

In a subduction environment (in Chile, the oceanic Nazca plate is sliding underneath the South American plate and heading down to the mantle) a distance of 37 miles, or about 60 kilometers, is really not that deep at all. Usually, the feature that cuts off the seismic part of the earth is temperature; when rocks get too hot, they're able to flow and don't fracture. But in a subduction zone, the plate going down is fairly cold, and is able to fracture seismically to much greater depths.

 

For an example, here's a transect across the Sumatran subduction zone showing earthquake depths (in kilometers on the Vertical axis) versus horizontal distance across the subduction zone. In that zone, earthquakes can be resolved down to 700 kilometers depth, or something in the range of 400 miles deep.

 

Link

Edited November 15, 2007 by Balta1701

[farmteam]

Link

See what happens when I don't read every thread? I miss questions for me.

 

In a subduction environment (in Chile, the oceanic Nazca plate is sliding underneath the South American plate and heading down to the mantle) a distance of 37 miles, or about 60 kilometers, is really not that deep at all. Usually, the feature that cuts off the seismic part of the earth is temperature; when rocks get too hot, they're able to flow and don't fracture. But in a subduction zone, the plate going down is fairly cold, and is able to fracture seismically to much greater depths.

 

For an example, here's a transect across the Sumatran subduction zone showing earthquake depths (in kilometers on the Vertical axis) versus horizontal distance across the subduction zone. In that zone, earthquakes can be resolved down to 700 kilometers depth, or something in the range of 400 miles deep.

 

Link

 

Man, I could have answered this as well, since I'm learning all about it in a class I'm taking right now. Sure, I couldn't respond so eloquently, but I would get the gist.

 

And, in an attempt to at least look like I've learned something from my class....

 

There would be relatively few deaths because, in addition to the fact that it occurred in the middle of nowhere, damage from an earthquake depends largely on the types of buildings it hits. Buildings made out of stone and such are very susceptible to the seismic waves produced by the earthquake; wood frame building are much sturdier. In short: lots of people die if the earthquake hits areas that have buildings that are poorly constructed and/or made out of masonry, but relatively few people are affected if the buildings are made out of more "earthquake proof" materials.

Edited November 15, 2007 by farmteam

[DBAHO]

Going to be halting production at a lot of Copper Mines.

 

I imagine the price of Copper will be going back up quite a bit after this.

[Balta1701]

There would be relatively few deaths because, in addition to the fact that it occurred in the middle of nowhere, damage from an earthquake depends largely on the types of buildings it hits. Buildings made out of stone and such are very susceptible to the seismic waves produced by the earthquake; wood frame building are much sturdier. In short: lots of people die if the earthquake hits areas that have buildings that are poorly constructed and/or made out of masonry, but relatively few people are affected if the buildings are made out of more "earthquake proof" materials.

Well, one of the things also worth noting is that there tends to be a correlation between the economic well-being of an area and how earthquake proof an area is, especially in Earthquake prone regions. In most earthquake prone regions I can think of, large forests of the sort that one would need to supply wood for housing are pretty much absent. In the U.S., wood is imported to areas like CA from other growing regions, but thinking of areas like South America, India/Asia, etc., the building materials we see in the U.S. aren't always as common. In this region, I'm not totally certain, but this is a high mountain plateau, and therefore I wouldn't expect a lot of building wood to be available. I could be wrong of course, just guessing since I don't know the climate.

 

Beyond wood though, in general, it's a lot more expensive to make a building out of steel reinforced concrete than it is to make it out of brick or out of something like assemblies of the local rock. Which is one of the reasons smaller earthquakes, like the one in Bam, Iran a few years ago, do an awful lot of damage; they destroy pretty much every building in the area where they hit.

[Balta1701]

Going to be halting production at a lot of Copper Mines.

 

I imagine the price of Copper will be going back up quite a bit after this.

Chile, the world's biggest copper producer, was shaken by its largest earthquake since 2004, knocking out power to at least nine mines and reducing output of the metal. One woman was killed, state-run National Television said.

 

The magnitude 7.7 quake, which hit at 12:40 p.m. local time, was centered 170 kilometers (105 miles) north-northeast of the port city of Antof**asta in northern Chile, the U.S. Geological Survey said. Mines including BHP Billiton Ltd.'s Escondida, the world's largest copper mine, and Codelco's top deposit, Chuquicamata, lost power.

 

``It was a very strong quake,'' the government's spokesman, Ricardo Lagos Weber, said in comments to state-run National Television. ``There could be aftershocks.''

 

Panicked residents fled into the streets in cities in northern Chile and buildings swayed in the capital Santiago. The National Emergency Office said they don't yet know if the death of an elderly woman today in northern Chile was due to the quake.

 

Mines owned by Anglo American Plc, Xstrata Plc, Kinross Gold Corp. and Freeport-McMoRan Copper & Gold Inc. also reported power outages.

 

Copper prices marked their biggest gain since July 2006 in New York after the quake in Chile, which supplies 36 percent of the world's output of the metal.

Bloomberg

[southsider2k5]

Bloomberg

 

Copper is down 5% today