An earthquake that shook up Armenia

At 11.41am on the 7th December 1988, Armenia was thrown into chaos. The Spitak earthquake which occurred that morning remains the largest in that region since historical times with a magnitude of 6.8 according to the USGS (United States Geological Survey) [1]. This earthquake affected 40% of Armenian territory, devastating 3 major cities and killing over 25,000 people [2].

Aftermath of the 1988 Spitak Earthquake [3]
Armenia lies within the collision zone between the Eurasian and Arabian plates. The force of this collision has caused the Earth’s outer layer – its crust – to break open in a series of faults across Armenia. It was along one of these faults that the rupture (and the resulting earthquake) occurred in 1988.

Fast forward 30 years and I have just arrived in Armenia with my supervisor Tim and recently graduated MGeol student, Lanita. Our first two days are to be spent investigating evidence of earthquakes along a major active fault (the Pambak-Sevan-Syunik Fault). This fault runs through Lake Sevan towards the north-west and is part of the same fault system in which the Spitak rupture occurred.

Having fought our way through clouds of mosquitoes and spider-filled trees, we emerged at a clearing. Here, like a knife slicing out a chunk of cake, the flowing water had cut down into the ground exposing a three meter high cliff face – composed of layers of ancient lake beds, deposited one on top of the other.

Immediately a pattern in these layers could be seen, and although I spent many hours recording observations at millimetre-scale detail, I will spare you with a brief description! Layers of gravel and sand were covered by layers of fine mud… then again gravel… then again mud… then again gravel… then again… yeah okay you get my point.

But what did it mean?

A section of the ancient lake beds preserved in the river cliff face (and me!)

We began building up a picture. The mud layers were formed at the bottom of the lake where the water is deep and still. The gravel layers were formed at the lake edge – much like the pebble beaches we often see bordering a lake or sea today. Earthquakes can cause large areas of the ground to suddenly drop down relative to the surrounding area.  We speculated that every time there was an earthquake it caused gravel-covered ground to drop down deeper below lake level. Here the gravel became covered by a layer of mud. Slowly the ground relaxed (rose back up) allowing a second gravel layer to be deposited on top of the mud. Voila! – we have a gravel – mud – gravel sandwich.

As this process repeated itself we can see that every muddy bed represents a sudden drop in the ground level, i.e. an earthquake. We collected samples of fish bone and plant debris above and below these beds. These will allow us to constrain the timing of these earthquakes.

By gathering information on past earthquakes in the rock record, we can delve back in time and provide data on the frequency and timing of these events. This in turn can help people to predict when future earthquakes might occur, and plan accordingly.

As reported by the Armenian National Survey for Seismic Protection, the 1988 Spitak earthquake took the country unawares. The likelihood of high magnitude earthquakes occurring was greatly underestimated and construction had not been carried out to the correct standards for an area with earthquake risk [4]. Using this event as an example,  some insight can be gained about leadership during chaotic situations. A leader must be prepared to act rapidly in a crisis. Being well informed and having a predefined plan of action is key to this. Furthermore, leaders can help themselves out by looking to the future and planning for possible problems they might face. This is something to think about regarding leadership on all scales, from acting to prevent the growing global issues such as climate change and food shortage to getting insurance cover so that when you miss your flight, or your car breaks down it’s not the end of the world (both of which happened on this field trip!).

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I would like to thank Lord Laidlaw for providing this wonderful opportunity, the Laidlaw team at St Andrews for all their time and help, my supervisor Dr Tim Raub, fellow geologist Lanita Gutieva and all the wonderful people I met during my research – thank you for making my Armenian adventure so great and answering my endless questions!

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[1] United States Geological Survey. 1988. M 6.8 – Armenia – USGS Earthquake Hazards Program. [ONLINE] Available at: http://earthquake.usgs.gov/earthquakes/eventpage/usp0003pmm#executive. [Accessed 14 July 2018].

[2] Borunov, A.K, et al., 1991. Geological Consequences of the 1988 Spitak Earthquake (Amenia). Mountain Research and Development, Vol 11, No. 1, pp. 19 – 35.

[3] Hvaal, M. (2018). Spitak Earthquake: How Half of Armenia Was Wiped Out Within 30 Seconds. [online] Sputnik News. Available at: http://sptnkne.ws/cUQp
[Accessed 14 Jul. 2018].

[4] Balassanian, S. Y, et al., 1995. Retrospective analysis of the Spitak Earthquake. Annali Di Geofisca, Vol 38, pp. 3 – 4.


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