<p>It's a combination of two main things:</p>
<ol>
<li>Flexible buildings have a longer fundamental period and therefore are more sensitive to long-period waves.</li>
<li>Earthquakes generate waves with a range of frequencies (or periods, which is inverse of frequency). High-frequency (short-period) waves attenuate quickly (i.e., over short distances) but the long-period waves take more distance to attenuate (because they are longer). So, the long-period waves travel further.</li>
</ol>
<p>Other site-specific factors like basin effects also amplify long period ground motions. Like @user2821 said in the comments, the most significant damage in the 1985 Mexico City earthquake occurred on soil column with an elongated fundamental period of about 2 seconds, so mid- to high-rise buildings on the lacustrine soils did not fare well.</p>

CC BY-SA 4.0
2022-08-02T22:03:49.573Z
2022-08-02T22:03:49.573Z
a11
<p>Why and what could be the reasons for flexible buildings that are far from the epicenter of an earthquake being more sensitive to damage than those located near it.</p>

CC BY-SA 3.0
2017-02-12T18:53:06.583Z
Because they are built differently.  Look up earthquake engineering.
jamesqf
CC BY-SA 3.0
2017-02-13T01:41:17.370Z
@jamesqf, Indeed definitely important to the topic.  But are similarly engineered buildings all likely to fall at the same magnitude, or is there variation or additional factors that may play a factor?
JeopardyTempest
CC BY-SA 3.0
2017-02-13T01:43:40.440Z
@Taller de Control, I'm confused by the changes.  You're asking why similar neighboring buildings don't always get damaged the same?  Or you're asking if there are features of earthquakes that can cause more distant areas to be damaged more than those near the epicenter?  It seems you've changed the direction of your question with your newest edit.
JeopardyTempest
CC BY-SA 3.0
2017-02-13T01:44:01.340Z
@JeopardyTempest similar looking buildings may have very different construction, even something as simple as how many loadbearing walls it has or what type or brick can make a difference.
John
CC BY-SA 3.0
2017-02-13T02:20:20.077Z
@John, indeed. Can see the same in the Fujita Scale. Amazing the things that turn out important in damage surveys. That said, I take this as similar to the "why does a tornado seem to hit one house and skip another", and (even subtle) structural differences are certainly a big part of that, but I think they're also wondering if they are any other factors, and they've got me interested in such an answer as well.  Though if you do want to go into more details on things like loadbearing walls and materials, that'd be a great very useful answer as well!
JeopardyTempest
CC BY-SA 3.0
2017-02-13T02:33:55.233Z
@Jeopardy Tempest, I wonder if there are any characteristics in the physics of earthquakes, such as the distance to the epicenter that made them more sensitive to a building than to another one identically constructed, to suffer damages. Apparently in the Wellington NZ earthquake. August 13, 2013, buildings furthest from the epicenter (100 km in Wellington) suffered more damage than those in areas near the epicenter
(Http://www.stuff.co.nz/national/86639645/The-earthquake-from-an-engineers-perspective). I appreciate your comments.
Carlos
CC BY-SA 3.0
2017-02-13T02:45:49.880Z
well the source of an earthquake is usually deep underground so there should be a significant change in the angle that the sound waves come in at as you move away from the epicenter.
John
CC BY-SA 3.0
2017-02-13T03:13:30.247Z
@John,It means that the depth (h) of the epicenter of the earthquake correlates with the distance (r) in which the damage will be greater, for a magnitude (m) of the earthquake established as constant. That is, for greater depth of the epicenter (h) and for a greater distance r of the zone of the epicenter will produce greater damages. This would be erroneous if we do not take into account a domain of validity of the distance r, because this can not be infinite due to the attenuation of the seismic waves.
If this reasoning were valid, it would be great.
Carlos
CC BY-SA 3.0
2017-02-13T03:49:22.820Z
The local geology is an important factor. E.g. The 1985 Mexico City earthquake occurred at some distance, but Mexico City's location on soft lake sediments caused the damage.
user2821
CC BY-SA 4.0
2022-08-03T10:18:30.630Z
Rome is built on a sediment layer deposited on hard rock. That sediment layer filters out some frequencies and resonates other frequencies, therefore earthquakes there have some characteristic frequencies. There is a story, I don't know how much proven that there are many 4 and 6 stories buildings, but not 5 because 5 stories masonry buildings, built between 1500 and 1800 resonate with the characteristic quake frequencies.
FluidCode
<seismic-hazards>
Why would sensitive buildings, further away from the earthquake epicenter, be the ones that suffer more damage than those close to it?
Carlos
# Why would sensitive buildings, further away from the earthquake epicenter, be the ones that suffer more damage than those close to it?

(Asked by: username_0 on 2017-02-12)

Why and what could be the reasons for flexible buildings that are far from the epicenter of an earthquake being more sensitive to damage than those located near it.

**Tags:** seismic-hazards

> **Comments:**
> **username_1**: Because they are built differently.  Look up earthquake engineering.  
> **username_2**: @username_1, Indeed definitely important to the topic.  But are similarly engineered buildings all likely to fall at the same magnitude, or is there variation or additional factors that may play a factor?  
> **username_2**: @Taller de Control, I'm confused by the changes.  You're asking why similar neighboring buildings don't always get damaged the same?  Or you're asking if there are features of earthquakes that can cause more distant areas to be damaged more than those near the epicenter?  It seems you've changed the direction of your question with your newest edit.  
> **username_3**: @username_2 similar looking buildings may have very different construction, even something as simple as how many loadbearing walls it has or what type or brick can make a difference.  
> **username_2**: @username_3, indeed. Can see the same in the Fujita Scale. Amazing the things that turn out important in damage surveys. That said, I take this as similar to the "why does a tornado seem to hit one house and skip another", and (even subtle) structural differences are certainly a big part of that, but I think they're also wondering if they are any other factors, and they've got me interested in such an answer as well.  Though if you do want to go into more details on things like loadbearing walls and materials, that'd be a great very useful answer as well!  
> **username_0**: @Jeopardy Tempest, I wonder if there are any characteristics in the physics of earthquakes, such as the distance to the epicenter that made them more sensitive to a building than to another one identically constructed, to suffer damages. Apparently in the Wellington NZ earthquake. August 13, 2013, buildings furthest from the epicenter (100 km in Wellington) suffered more damage than those in areas near the epicenter (Http://www.stuff.co.nz/national/86639645/The-earthquake-from-an-engineers-perspective). I appreciate your comments.  
> **username_3**: well the source of an earthquake is usually deep underground so there should be a significant change in the angle that the sound waves come in at as you move away from the epicenter.  
> **username_0**: @username_3,It means that the depth (h) of the epicenter of the earthquake correlates with the distance (r) in which the damage will be greater, for a magnitude (m) of the earthquake established as constant. That is, for greater depth of the epicenter (h) and for a greater distance r of the zone of the epicenter will produce greater damages. This would be erroneous if we do not take into account a domain of validity of the distance r, because this can not be infinite due to the attenuation of the seismic waves. If this reasoning were valid, it would be great.  
> **username_4**: The local geology is an important factor. E.g. The 1985 Mexico City earthquake occurred at some distance, but Mexico City's location on soft lake sediments caused the damage.  
> **username_5**: Rome is built on a sediment layer deposited on hard rock. That sediment layer filters out some frequencies and resonates other frequencies, therefore earthquakes there have some characteristic frequencies. There is a story, I don't know how much proven that there are many 4 and 6 stories buildings, but not 5 because 5 stories masonry buildings, built between 1500 and 1800 resonate with the characteristic quake frequencies.  

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## 1 answers

### Answer by username_6 on 2022-08-02. Score: 1

It's a combination of two main things:

1. Flexible buildings have a longer fundamental period and therefore are more sensitive to long-period waves.
2. Earthquakes generate waves with a range of frequencies (or periods, which is inverse of frequency). High-frequency (short-period) waves attenuate quickly (i.e., over short distances) but the long-period waves take more distance to attenuate (because they are longer). So, the long-period waves travel further.

Other site-specific factors like basin effects also amplify long period ground motions. Like @username_4 said in the comments, the most significant damage in the 1985 Mexico City earthquake occurred on soil column with an elongated fundamental period of about 2 seconds, so mid- to high-rise buildings on the lacustrine soils did not fare well.


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