<p>According to this <a href="http://jardfraedikort.is/index_enska.html" rel="nofollow noreferrer">geological map of iceland</a> it is the Urðarháls, an interglacial shield, i.e. a <strike>dolomite</strike> shield volcano that got scraped by glacial activity The hole in the middle is the pit crater.
You can find some cool pictures of it if you google the name with the correct icelandic letters.</p>

CC BY-SA 4.0
2020-03-11T10:12:12.680Z
I've found this "dolomite" volcano information somewhere on the web, but it must be a mistranslation: dolomite is a sedimentary carbonate rock, I doubt it can be erupted from a volcano, even at Ol Doinyo Lengai! :)
Jean-Marie Prival
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2020-03-11T10:27:43.863Z
@Jean-Marie Prival You are obviously correct!
R.K.
CC BY-SA 4.0
2020-03-11T16:19:08.927Z
thanks for your answer! The geological map doesn't seem to work with my browser - which one do you use?
robaki
CC BY-SA 4.0
2020-03-11T16:32:15.597Z
For me, it works with Chrome, Firefox or Edge. The original link for the "Geological Web Map" comes from this page: https://en.isor.is/geological-maps-geological-web-map
R.K.
CC BY-SA 4.0
2020-03-11T17:47:03.513Z
thanks, I use Firefox too, and turning off addons didn't help. Well, this is not a problem for this site anyway. Thanks again for your answer, the Urðarháls pictures are cool indeed!
robaki
CC BY-SA 4.0
2020-03-11T09:56:17.773Z
2020-03-11T10:26:48.250Z
2020-03-11T10:26:48.250Z
R.K.
<p>The place is called Urðarháls. I could not find much information about it in the scientific literature... It is mentioned in <a href="https://timarit.is/page/7011459#page/n15/mode/2up" rel="noreferrer">Sigmarsson &amp; Halldórsson (2015)</a>: they say it's an interglacial basaltic shield volcano, possibly associated with the Askja volcanic system. The fact that the volcano was eroded by glaciers probably explains the colour difference with the surrounding "fresh", postglacial lavas.</p>

<p>The crater looks like a pit crater to me: it probably collapsed when lava was drained somewhere else, leaving an empty chamber beneath it. Another good example of pit crater is the Dolomieu, on Piton de la Fournaise, which collapsed in 2007. Look at <a href="https://doi.org/10.1016/j.jvolgeores.2008.11.005" rel="noreferrer">Staudacher et al. (2009)</a>: compare figure 3, before the collapse, and figure 11, after.</p>

<p>Note that the authors use the term "caldera", which is loosely defined... What Wikipedia calls a <a href="https://en.wikipedia.org/wiki/Caldera#Non-explosive_calderas" rel="noreferrer">non-explosive caldera</a> would be referred to as a pit crater by some. I guess the two terms kind of overlap.</p>

CC BY-SA 4.0
2020-03-11T16:29:11.743Z
nice, thanks for the literature pointers and pointing out the caldera-crater issue
robaki
CC BY-SA 4.0
2020-03-11T10:07:33.577Z
2020-03-11T10:14:42.657Z
2020-03-11T10:14:42.657Z
Jean-Marie Prival
<p>I was studying a satellite map of Iceland and came across an interesting, but unnamed feature located between Vatnajökull glacier and Trölladyngja volcano (between 64°50'35"N, 17°11'21"W and 64°48'33"N, 17°04'25"W ; <a href="https://www.google.com/maps/@64.8319456,-17.1420462,6217m/data=!3m1!1e3" rel="nofollow noreferrer">link to google maps</a>). It is a distinct, bright patch of land, around 6.5km across with an indentation in the center. Its color and texture are different than these of the lava field next to it and the indentation looks (to my untrained eye) more like a collapsed lava bubble than a caldera.</p>

<p>Is it a volcano or something else?</p>

<p><a href="https://i.sstatic.net/sU400.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/sU400.png" alt="enter image description here"></a></p>

CC BY-SA 4.0
2020-03-12T17:50:18.667Z
@Fred are you sure that attaching this picture is OK? I was considering doing the same, but it seems that cannot be used without permission:
https://law.stackexchange.com/questions/37291/are-the-images-pulled-from-the-google-places-api-allowed-to-be-used-on-our-websi/37292
robaki
CC BY-SA 4.0
2020-03-13T01:14:55.987Z
The question you reference discusses the *commercial use* of images.
justCal
CC BY-SA 4.0
2020-03-13T05:01:58.420Z
In addition to what @user2448131: states, there's a *2020 Google* watermark on the picture to prevent commercial usage
Fred
<volcanology><geomorphology><identification-request>
Geomorphological feature identification
robaki
# Geomorphological feature identification

(Asked by: username_0 on 2020-03-11)

I was studying a satellite map of Iceland and came across an interesting, but unnamed feature located between Vatnajökull glacier and Trölladyngja volcano (between 64°50'35"N, 17°11'21"W and 64°48'33"N, 17°04'25"W ; [link to google maps](https://www.google.com/maps/@64.8319456,-17.1420462,6217m/data=!3m1!1e3)). It is a distinct, bright patch of land, around 6.5km across with an indentation in the center. Its color and texture are different than these of the lava field next to it and the indentation looks (to my untrained eye) more like a collapsed lava bubble than a caldera.

Is it a volcano or something else?

[![enter image description here](https://i.sstatic.net/sU400.png)](https://i.sstatic.net/sU400.png)

**Tags:** volcanology, geomorphology, identification-request

> **Comments:**
> **username_0**: @username_2 are you sure that attaching this picture is OK? I was considering doing the same, but it seems that cannot be used without permission: https://law.stackexchange.com/questions/37291/are-the-images-pulled-from-the-google-places-api-allowed-to-be-used-on-our-websi/37292  
> **username_1**: The question you reference discusses the *commercial use* of images.  
> **username_2**: In addition to what @user2448131: states, there's a *2020 Google* watermark on the picture to prevent commercial usage  

---

## 2 answers

### Answer by username_4 on 2020-03-11. Score: 6 | Accepted answer

The place is called Urðarháls. I could not find much information about it in the scientific literature... It is mentioned in [Sigmarsson & Halldórsson (2015)](https://timarit.is/page/7011459#page/n15/mode/2up): they say it's an interglacial basaltic shield volcano, possibly associated with the Askja volcanic system. The fact that the volcano was eroded by glaciers probably explains the colour difference with the surrounding "fresh", postglacial lavas.

The crater looks like a pit crater to me: it probably collapsed when lava was drained somewhere else, leaving an empty chamber beneath it. Another good example of pit crater is the Dolomieu, on Piton de la Fournaise, which collapsed in 2007. Look at [Staudacher et al. (2009)](https://doi.org/10.1016/j.jvolgeores.2008.11.005): compare figure 3, before the collapse, and figure 11, after.

Note that the authors use the term "caldera", which is loosely defined... What Wikipedia calls a [non-explosive caldera](https://en.wikipedia.org/wiki/Caldera#Non-explosive_calderas) would be referred to as a pit crater by some. I guess the two terms kind of overlap.

> **Comments:**
> **username_0**: nice, thanks for the literature pointers and pointing out the caldera-crater issue  

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### Answer by username_3 on 2020-03-11. Score: 3

According to this [geological map of iceland](http://jardfraedikort.is/index_enska.html) it is the Urðarháls, an interglacial shield, i.e. a dolomite shield volcano that got scraped by glacial activity The hole in the middle is the pit crater.
You can find some cool pictures of it if you google the name with the correct icelandic letters.

> **Comments:**
> **username_4**: I've found this "dolomite" volcano information somewhere on the web, but it must be a mistranslation: dolomite is a sedimentary carbonate rock, I doubt it can be erupted from a volcano, even at Ol Doinyo Lengai! :)  
> **username_3**: @username_4 You are obviously correct!  
> **username_0**: thanks for your answer! The geological map doesn't seem to work with my browser - which one do you use?  
> **username_3**: For me, it works with Chrome, Firefox or Edge. The original link for the "Geological Web Map" comes from this page: https://en.isor.is/geological-maps-geological-web-map  
> **username_0**: thanks, I use Firefox too, and turning off addons didn't help. Well, this is not a problem for this site anyway. Thanks again for your answer, the Urðarháls pictures are cool indeed!  

---

