<p>The two geological faults that may be responsible of large earthquake in proximity of the museum are:</p>

<ul>
<li>Hollywood fault;</li>
<li>Santa Monica fault (actually many branches, but they all go together as Santa Monica fault).</li>
</ul>

<p>The museum seems to be enough far away from the fault trace (the surface expression of the fault itself), so it is unlikely that there will be a major shift in the soil. </p>

<p>However, the museum may sink in the soil due to the earthquake mobilizing the soil, especially if composed of loose sand.</p>

<p>The phenomena responsible of the museum "falling in the soil during an earthquake" is liquefaction. The geological service of California provides you an interactive map to check if a certain address may be under liquefaction hazard <a href="https://www.americangeosciences.org/critical-issues/maps/interactive-map-california-earthquake-hazard-zones" rel="nofollow noreferrer">https://www.americangeosciences.org/critical-issues/maps/interactive-map-california-earthquake-hazard-zones</a> and ...</p>

<p>at the moment the interactive map is not accesible to me. Sorry :) </p>

<p>If liquefaction is possible, either the tar may quickly move and sputter on/in the museum, or the museum may sink in and later tar may infiltrate slowly in the building.</p>

CC BY-SA 4.0
2020-03-05T20:23:45.727Z
Thank's for your answer! I was hoping that the museum was built on bedrock and the tar pit was just a hole in that rock providing access to oil (tar) trapped in layers below. But it's just soil and not rock? I wish there were a diagram with a cross-section of this kind of tar pit that shows what keeps the soil and tar from just eventually mixing together. I'd always thought that it was rock.
uhoh
CC BY-SA 4.0
2020-03-06T09:58:39.450Z
@uhoh providing cross section in urban environment is very complicated. Check the app from the californian geological survey, if the museum is on a "possible liquefaction area" then it means it is very likely to stand on a sandy/soil basement. Which I expect to be the case, since reading from here: https://tarpits.org/research-collections/tar-pits-our-research/geology
"the Santa Monica Mountains uplifted and rivers flowing down brought large amounts of sands and gravels that subsequently buried the remains of plants and animals trapped on the surface of the asphalt  seeps at Rancho La Brea"
EarlGrey
CC BY-SA 4.0
2020-03-06T10:12:28.387Z
This area was studied *long before* it was built up [1](https://i.sstatic.net/7WjHF.jpg) [2](https://i.sstatic.net/frFAx.jpg) due to both it's economic and scientific interest, so I'm hoping that there might be more understood about the subsurface structure here.
uhoh
CC BY-SA 4.0
2020-03-06T11:03:59.053Z
Don't confuse exploited with studied ... if the target was oil, then they were looking for oil and whatever in between the surface and the reservoir was just "tough or tougher" material to be drilled.
Said this just a couple of drlling/mud logs from the wells perforated there would help a lot to get your answer.
EarlGrey
CC BY-SA 4.0
2020-03-05T15:45:16.427Z
2020-03-05T15:45:16.427Z
EarlGrey
<p>LACMA (the <a href="https://en.wikipedia.org/wiki/Los_Angeles_County_Museum_of_Art" rel="noreferrer">Los Angeles County Museum of Art</a>) is built right next to the famous La Brea Tar Pits and that keeps me up at night<sup>†</sup>. </p>

<p><strong>Question:</strong> What is the subsurface structure like adjacent to the Lake Pit? I'm wondering if the LA County Museum of Art and other buildings near the Lake Pit could actually fall in some day. Is the museum built on bedrock and the tar pit next to it is just a small hole in it, or if "the big one" comes (major earthquake) could soil shift and the art museum end up submersed in tar? </p>

<p><sup>†</sup>no it doesn't, drinking too much coffee keeps me up at night.</p>

<p>Google Maps of La Brea Tar Pit and LACMA</p>

<p><a href="https://i.sstatic.net/0zx15.jpg" rel="noreferrer"><img src="https://i.sstatic.net/0zx15.jpg" alt="Google Maps of La Brea Tar Pit and LACMA"></a></p>

<p>Ground truth: LA/Hollywood, so plastic dinosaur...</p>

<p><a href="https://i.sstatic.net/DsE3A.jpg" rel="noreferrer"><img src="https://i.sstatic.net/DsE3A.jpg" alt="Google Maps of La Brea Tar Pit and LACMA"></a></p>

<p><a href="https://i.sstatic.net/Jh6zF.png" rel="noreferrer"><img src="https://i.sstatic.net/Jh6zF.png" alt="Google Maps of La Brea Tar Pit"></a></p>

CC BY-SA 4.0
2020-03-05T08:43:51.437Z
The real question is: could the museum be propelled into Trinidad asphalt lake by an asteroid (and fossilize once there)?
Jean-Marie Prival
CC BY-SA 4.0
2020-03-06T05:09:16.330Z
NOT dinosaur, mammoth (or perhaps mastodon).  And to answer the question, we'd have to know a lot more about the subsurface geology of the area - or even the elevations: are the museum buildings significantly upslope from the tar pits?  We'd also have to know about the seismic engineering that went into the buildings' designs.
jamesqf
CC BY-SA 4.0
2020-03-06T10:06:05.433Z
@jamesqf I thought those were brontosauri, no? ;-) So with "Is the museum built on bedrock and the tar pit next to it is just a small hole in it, or..." I'm asking for precisely "the subsurface geology of the area". Since this has been such a geologically interesting area I'm sure this has been studied, examined and written about extensively, I just don't know where to begin to read up on it.
uhoh
CC BY-SA 4.0
2020-03-06T19:33:59.270Z
@uhoh: No. Brontosaurus has long neck and tail, doesn't have tusks or trunk.  Not to mention that the tar pits seem to have formed ~40 million years after the extinction of the dinosaurs.
jamesqf
CC BY-SA 4.0
2020-03-06T22:08:02.507Z
@jamesqf a little bit like [this](https://biology.stackexchange.com/q/64666/27918)?
uhoh
CC BY-SA 4.0
2021-01-24T22:27:12.560Z
[Chart of strata formations at La Brea Pots](https://tessa.lapl.org/cdm/ref/collection/photos/id/84577)
Keith McClary
CC BY-SA 4.0
2021-01-24T22:48:51.357Z
@KeithMcClary oh that is so cool! :-)
uhoh
CC BY-SA 4.0
2021-01-27T21:14:17.397Z
@KeithMcClary it suggests to me that the museum is on solid ground (rock?), and the tar pit is just a depression in that, with a small crack down to deeper stuff. In other words, the museum is not going to fall into the tar pit during an earthquake. Consider writing that up as an answer? There's about 1 more day plus a 1 day grace period for the bounty.
uhoh
CC BY-SA 4.0
2021-01-27T23:24:10.103Z
In the description it says "recent alluvium (10000-25000 years ago)" I'm not sure what ["alluvium" means](https://en.wikipedia.org/wiki/Alluvium#Definitions) exactly.
Keith McClary
<structural-geology><bedrock><asphalt-lakes>
Could the LA County Museum of Art fall into the LaBrea Tar pit during an earthquake?
uhoh
# Could the LA County Museum of Art fall into the LaBrea Tar pit during an earthquake?

(Asked by: username_0 on 2020-03-05)

LACMA (the [Los Angeles County Museum of Art](https://en.wikipedia.org/wiki/Los_Angeles_County_Museum_of_Art)) is built right next to the famous La Brea Tar Pits and that keeps me up at night†.

**Question:** What is the subsurface structure like adjacent to the Lake Pit? I'm wondering if the LA County Museum of Art and other buildings near the Lake Pit could actually fall in some day. Is the museum built on bedrock and the tar pit next to it is just a small hole in it, or if "the big one" comes (major earthquake) could soil shift and the art museum end up submersed in tar?

†no it doesn't, drinking too much coffee keeps me up at night.

Google Maps of La Brea Tar Pit and LACMA

[![Google Maps of La Brea Tar Pit and LACMA](https://i.sstatic.net/0zx15.jpg)](https://i.sstatic.net/0zx15.jpg)

Ground truth: LA/Hollywood, so plastic dinosaur...

[![Google Maps of La Brea Tar Pit and LACMA](https://i.sstatic.net/DsE3A.jpg)](https://i.sstatic.net/DsE3A.jpg)

[![Google Maps of La Brea Tar Pit](https://i.sstatic.net/Jh6zF.png)](https://i.sstatic.net/Jh6zF.png)

**Tags:** structural-geology, bedrock, asphalt-lakes

> **Comments:**
> **username_1**: The real question is: could the museum be propelled into Trinidad asphalt lake by an asteroid (and fossilize once there)?  
> **username_2**: NOT dinosaur, mammoth (or perhaps mastodon).  And to answer the question, we'd have to know a lot more about the subsurface geology of the area - or even the elevations: are the museum buildings significantly upslope from the tar pits?  We'd also have to know about the seismic engineering that went into the buildings' designs.  
> **username_0**: @username_2 I thought those were brontosauri, no? ;-) So with "Is the museum built on bedrock and the tar pit next to it is just a small hole in it, or..." I'm asking for precisely "the subsurface geology of the area". Since this has been such a geologically interesting area I'm sure this has been studied, examined and written about extensively, I just don't know where to begin to read up on it.  
> **username_2**: @username_0: No. Brontosaurus has long neck and tail, doesn't have tusks or trunk.  Not to mention that the tar pits seem to have formed ~40 million years after the extinction of the dinosaurs.  
> **username_0**: @username_2 a little bit like [this](https://biology.stackexchange.com/q/64666/27918)?  
> **username_3**: [Chart of strata formations at La Brea Pots](https://tessa.lapl.org/cdm/ref/collection/photos/id/84577)  
> **username_0**: @username_3 oh that is so cool! :-)  
> **username_0**: @username_3 it suggests to me that the museum is on solid ground (rock?), and the tar pit is just a depression in that, with a small crack down to deeper stuff. In other words, the museum is not going to fall into the tar pit during an earthquake. Consider writing that up as an answer? There's about 1 more day plus a 1 day grace period for the bounty.  
> **username_3**: In the description it says "recent alluvium (10000-25000 years ago)" I'm not sure what ["alluvium" means](https://en.wikipedia.org/wiki/Alluvium#Definitions) exactly.  

---

## 1 answers

### Answer by username_4 on 2020-03-05. Score: 3

The two geological faults that may be responsible of large earthquake in proximity of the museum are:

* Hollywood fault;
* Santa Monica fault (actually many branches, but they all go together as Santa Monica fault).

The museum seems to be enough far away from the fault trace (the surface expression of the fault itself), so it is unlikely that there will be a major shift in the soil.

However, the museum may sink in the soil due to the earthquake mobilizing the soil, especially if composed of loose sand.

The phenomena responsible of the museum "falling in the soil during an earthquake" is liquefaction. The geological service of California provides you an interactive map to check if a certain address may be under liquefaction hazard <https://www.americangeosciences.org/critical-issues/maps/interactive-map-california-earthquake-hazard-zones> and ...

at the moment the interactive map is not accesible to me. Sorry :)

If liquefaction is possible, either the tar may quickly move and sputter on/in the museum, or the museum may sink in and later tar may infiltrate slowly in the building.

> **Comments:**
> **username_0**: Thank's for your answer! I was hoping that the museum was built on bedrock and the tar pit was just a hole in that rock providing access to oil (tar) trapped in layers below. But it's just soil and not rock? I wish there were a diagram with a cross-section of this kind of tar pit that shows what keeps the soil and tar from just eventually mixing together. I'd always thought that it was rock.  
> **username_4**: @username_0 providing cross section in urban environment is very complicated. Check the app from the californian geological survey, if the museum is on a "possible liquefaction area" then it means it is very likely to stand on a sandy/soil basement. Which I expect to be the case, since reading from here: https://tarpits.org/research-collections/tar-pits-our-research/geology "the Santa Monica Mountains uplifted and rivers flowing down brought large amounts of sands and gravels that subsequently buried the remains of plants and animals trapped on the surface of the asphalt  seeps at Rancho La Brea"  
> **username_0**: This area was studied *long before* it was built up [1](https://i.sstatic.net/7WjHF.jpg) [2](https://i.sstatic.net/frFAx.jpg) due to both it's economic and scientific interest, so I'm hoping that there might be more understood about the subsurface structure here.  
> **username_4**: Don't confuse exploited with studied ... if the target was oil, then they were looking for oil and whatever in between the surface and the reservoir was just "tough or tougher" material to be drilled. Said this just a couple of drlling/mud logs from the wells perforated there would help a lot to get your answer.  

---

