Missing

Earthquakes subsiding in Saudi Arabia


Al-Qider volcano in western Saudi Arabia. Image courtesy of Ahmed Al-Hussaini.

After a week's worth of worry, it appears that the seismicity in western Saudi Arabia is subsiding. The latest statement from Zuhair Nawab, the head of the SGS, is that over the past four days with fewer and less severe aftershocks. If this continues, people who have evacuated the area around Al Ais might be able to return to their homes in a few days. However, it is important to note that even though officials suggest the seismicity is waning (and there may be indications this is not entirely accurate), the swarm is definitely not "over".

Rumors/reports of increased radon gas and changes in the chemistry of the well waters near the earthquakes epicenters appear to be unfounded. Saad al Mohlafi, the deputy director of the National Observation Centre, said that "no gases indicating an imminent eruption of a volcano have been found in Alees [Al-Ais]." This contradicts a lot of what was being said earlier last week and would support the idea that these earthquakes might not be directly related to any imminent eruption from Harrat Lunayyir. However, this does not preclude the idea that these earthquake could have been the product of a subvolcanic intrusion of magma underneath the volcano field that did not lead to an eruption. These contradictory reports and rumors have lead to more confusion for the residents of the region.

I am still flabbergasted by comments like this from Zuhair Nawab: "The magma level is still at eight kilometres ... I don't know where the media got this worrying level from." I have yet to find any information about how the SGS (a) knows what depth there might be melt - i.e., magma and (b) what "magma level" even means. The article linked here (and above) from The National in Abu Dhabi does suffer from a lot of mish-mashed science, such as bring up that, according to the EPA, radon "is reportedly the second-most frequent cause of lung cancer, after cigarette smoking." How does this help our understanding of any potential precursors to eruption? It really doesn't, but it does give an false pretense of scientific authority to the article.

I'll keep an eye on how events might change in western Saudi Arabia - remember, just because seismicity seems to be waning now doesn't mean this won't change in the near future. In any case, these earthquakes were a fascinating study in how rumor can effect people's perceptions of the perceived volcanic danger. If another earthquake swarm were to begin in the next months or years, the reaction might be very different.

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