<p>Complementing the answer by @seismo_steve, two other geophysical ways of
detecting magma chambers are through their density and conductivity anomalies.</p>

<p>Seismic tomography is able to detect the chambers because they cause an anomaly
in the propagation velocity of seismic waves.
Likewise, the chambers cause an <strong>anomaly in the gravity field</strong> because
their density is different from the surrounding/reference value.
Geophysicists can use this gravity anomaly to estimate the size and shape of
the magma chamber
(see <a href="http://onlinelibrary.wiley.com/doi/10.1002/2013JB010168/abstract">this paper by Chaves and Ussami, 2013, for an example also in Yellowstone</a>).</p>

<p>Long-wavelength <strong>electromagnetic methods</strong>, like
<a href="http://en.wikipedia.org/wiki/Magnetotellurics">magnetotellurics</a>,
might also be able to detect the electrical conductivity anomaly associated
with the magma chamber (though there are some restrictions).
See <a href="http://library.seg.org/doi/abs/10.1190/1.1441987">this classic paper by Newman et al. (1985)</a>.</p>

CC BY-SA 3.0
2014-05-08T13:52:18.087Z
2014-05-08T13:52:18.087Z
Leo Uieda
<p>I am a seismologist, not a volcanologist, but we can use a method called seismic tomography to understand the size of magma chambers. </p>

<p>This method is similar to a medical CT scan - the magma mush will have a slower seismic wavespeed than the surrounding 'normal' rock. Therefore, we can use this to determine the size of magma chambers from a tomographic image.</p>

<p>Even if a volcano does not appear to be active at the surface, it could still overlie a magmatic anomaly.</p>

<p>This approach was recently used to estimate the seismic of the Yellowstone magmatic body. See this paper: <a href="http://onlinelibrary.wiley.com/doi/10.1002/2014GL059588/abstract">http://onlinelibrary.wiley.com/doi/10.1002/2014GL059588/abstract</a></p>

<p>Seismic tomography can theoretically be applied to any region, but we just need to have enough seismic sources nearby (e.g. earthquakes) to be able to do this accurately. </p>

CC BY-SA 3.0
2014-05-07T14:56:42.710Z
2014-05-07T14:56:42.710Z
seismo_steve
<p><a href="http://en.wikipedia.org/wiki/Supervolcano">Supervolcanos</a> have occurred in the recent geological past, but not within the past 74,000 years. <strong>Is it possible to find the magma chambers with no previous history of supervolcanic activity that are likely to produce supervolcanos?</strong></p>

CC BY-SA 3.0
2014-05-05T18:12:09.440Z
I'm afraid I'm not clear on what information you're after - whether we can image magma chambers currently underlying known supervolcanoes (and if so what information we can get e.g. are the contents solid, mushy or liquid; can we tell anything about injection rates; etc) versus identifying potential supervolcanoes with no current surface expression. If you can flesh out your request a bit, I'll happily respond :-) (PS it'd be nice if you added at least a brief textual image caption/description for accessibility purposes.)
kaberett
CC BY-SA 3.0
2014-05-06T00:50:52.867Z
@blunders By "future super-eruption sites", do you mean locations with no previous history of supervolcanic activity? Or predictive abilities with respect to known supervolcanoes? (Also, it'd be great if you could edit the clarifications into the main question For The Future when comments will vanish :-)
kaberett
<volcanology><volcanoes>
Is it possible to find the magma chambers that produce supervolcanos?
blunders
# Is it possible to find the magma chambers that produce supervolcanos?

(Asked by: username_0 on 2014-05-05)

[Supervolcanos](http://en.wikipedia.org/wiki/Supervolcano) have occurred in the recent geological past, but not within the past 74,000 years. **Is it possible to find the magma chambers with no previous history of supervolcanic activity that are likely to produce supervolcanos?**

**Tags:** volcanology, volcanoes

> **Comments:**
> **username_1**: I'm afraid I'm not clear on what information you're after - whether we can image magma chambers currently underlying known supervolcanoes (and if so what information we can get e.g. are the contents solid, mushy or liquid; can we tell anything about injection rates; etc) versus identifying potential supervolcanoes with no current surface expression. If you can flesh out your request a bit, I'll happily respond :-) (PS it'd be nice if you added at least a brief textual image caption/description for accessibility purposes.)  
> **username_1**: @username_0 By "future super-eruption sites", do you mean locations with no previous history of supervolcanic activity? Or predictive abilities with respect to known supervolcanoes? (Also, it'd be great if you could edit the clarifications into the main question For The Future when comments will vanish :-)  

---

## 2 answers

### Answer by username_3 on 2014-05-07. Score: 12 | Accepted answer

I am a seismologist, not a volcanologist, but we can use a method called seismic tomography to understand the size of magma chambers.

This method is similar to a medical CT scan - the magma mush will have a slower seismic wavespeed than the surrounding 'normal' rock. Therefore, we can use this to determine the size of magma chambers from a tomographic image.

Even if a volcano does not appear to be active at the surface, it could still overlie a magmatic anomaly.

This approach was recently used to estimate the seismic of the Yellowstone magmatic body. See this paper: <http://onlinelibrary.wiley.com/doi/10.1002/2014GL059588/abstract>

Seismic tomography can theoretically be applied to any region, but we just need to have enough seismic sources nearby (e.g. earthquakes) to be able to do this accurately.


---

### Answer by username_2 on 2014-05-08. Score: 12

Complementing the answer by @seismo\_steve, two other geophysical ways of
detecting magma chambers are through their density and conductivity anomalies.

Seismic tomography is able to detect the chambers because they cause an anomaly
in the propagation velocity of seismic waves.
Likewise, the chambers cause an **anomaly in the gravity field** because
their density is different from the surrounding/reference value.
Geophysicists can use this gravity anomaly to estimate the size and shape of
the magma chamber
(see [this paper by Chaves and Ussami, 2013, for an example also in Yellowstone](http://onlinelibrary.wiley.com/doi/10.1002/2013JB010168/abstract)).

Long-wavelength **electromagnetic methods**, like
[magnetotellurics](http://en.wikipedia.org/wiki/Magnetotellurics),
might also be able to detect the electrical conductivity anomaly associated
with the magma chamber (though there are some restrictions).
See [this classic paper by Newman et al. (1985)](http://library.seg.org/doi/abs/10.1190/1.1441987).


---

