Map of
northwestern Turkey depicting the fault lines running between the Anatolian
Block and the Eurasian Plate and the location of the epicentre of the İzmit
earthquake of Aug. 17, 1999. (Encyclopedia Britannica, Inc, n.d.)
At around 3 am local time on the 17th of
August 1999, northwestern Turkey was struck by an earthquake with a magnitude
of 7.4 (Gillies et al., 2001). It occurred on the northernmost strand of the
Northern Anatolian fault system with an initial shock that lasted less than a
minute. It was then followed by two smaller aftershocks on August 19th
(USGS, 2022).
The main regions affected by this earthquake were the densely
populated cities of Izmit and Adapazari, which are located in the provinces of Kocaeli
and Sakarya. This was mainly due to the epicentre being located about 11km
southeast of Izmit. These afflicted regions were Turkey’s industrial core, with
Istanbul and nearby provinces accounting for approximately one-third of the
nation’s total output (Bibbee et al., 2000).
There were many impacts caused by the initial
earthquake. Many apartment buildings entirely collapsed, killing a large number
of individuals who had been asleep when the earthquake struck. It took five and
a half days to control and put out a fire in the Tupras oil refiners, which at
the time processed 86% of Turkey’s oil. The fire had threatened to spread to
neighbouring industrial facilities. Surface breaks cut into the toe of the fan
delta where the town of Degirmendere was located at the western end of the
rapture zone. This resulted in a slump, 100m normal to the coastline. Parts of
Degimendere slid under water, including a hotel as well as several stores and restaurants.
The severity, scope, and loss of life during the first two days were vastly
underestimated. (Barka, 1999)
At least 17,118 people were killed, close to 50,000
were wounded, about 600,000 were left homeless, and the damage ranged from 3 to
6.5 billion USD in the provinces of Kocaeli and Sakarya, and Instanbul. (USGS,
2022).
In the past, Turkish builders employed conventional,
time-tested construction techniques to reduce damage from earthquakes. However,
rapid growth in population in the early 1980s changed this (Gillies et al.,
2001) and the earthquake exposed several flaws in urban design and construction
methods that had increased the infrastructure and death toll of the disaster:
Large-scale urbanisation had been approved where
liquefiable soil was present. Because the majority of the impacted
infrastructure was less than twenty years old, the horrific death toll
resulting from poor foundation systems – one of the main causes of destruction
in Adapazari – is all the more tragic.
Problems with construction engineering were a
significant additional cause of the catastrophe. Most collapsed multi-story
buildings had weak ground floor levels due to their use for commercial
purposes, with fewer retaining walls and higher ceilings, which led to ground
floor collapses. The widespread usage of hollow clay tiles that are not
reinforced to build interior and exterior walls had a negative impact on how
well the structural frame performed during the earthquake. (Bibbee et al.,
2000).
Buildings
damaged by the İzmit earthquake in Turkey, 1999 (Encyclopedia Britannica, Inc, n.d.)
The challenges in mounting a prompt and efficient
official emergency response to the earthquake may have contributed to the
significant loss of human life. This was mostly because it happened at 3 am
with many of the emergency response officials among those who were trapped
inside the collapsed buildings. As well as this the majority of the emergency
response equipment was destroyed or damaged. (Bibbee et al., 2000).
Poor communication and significant damage to the main
route linking Istanbul and Ankara lead to further delays in rescue efforts. It was further exacerbated by people
blocking other routes when attempting to reach family and friends in the
worst-affected areas (Barka, 1999). Over
600 000 individuals were forced to seek emergency shelter as a result of the
earthquake's damage to or destruction of over more than 300 000 dwelling
units. The government made the early decision that stronger temporary housing
have to be used in place of tents due to the impending cold and wet winter
weather. (Bibbee et al., 2000). Private contractors were criticised heavily for
their work and for utilising cheap, subpar materials as the majority of the
fatalities were caused by the collapse of residential buildings. Although
several contractors were criminally charged, relatively few of them were
convicted. The public chastised officials for not enforcing building
regulations about earthquake-resistant designs. (Tikkanen., 2022).
Video: https://www.youtube.com/watch?v=T0VV_JOmNps
References:
Barka, A., 1999. The 17 August 1999
Izmit earthquake. Science, 285(5435), pp.1858–1859.
Bibbee, A. et al., 2000. Economic
effects of the 1999 Turkish earthquakes. OECD Economics Department Working
Papers.
Earthquake.usgs.gov. 2022. [online] Available at: <https://earthquake.usgs.gov/earthquakes/eventpage/usp0009d4z/executive>
[Accessed 10 September 2022].
Encyclopedia Britannica, Inc, n.d. Map of
northwestern Turkey depicting the location of the epicentre of the İzmit
earthquake of Aug. 17, 1999.. [image] Available at:
<https://www.britannica.com/event/Izmit-earthquake-of-1999> [Accessed 12
September 2022].
Gillies, A., Anderson, D., Mitchell, D., Tinawi, R.,
Saatcioglu, M., Gardner, N. and Ghoborah, A., 2001. The August 17, 1999,
Kocaeli (Turkey) earthquake lifelines and preparedness. Canadian
Journal of Civil Engineering, 28(6), pp.881-890.
Tikkanen., A., 2022. İzmit earthquake of 1999 |
Turkey. [online] Encyclopedia Britannica. Available at:
<https://www.britannica.com/event/Izmit-earthquake-of-1999> [Accessed 10
September 2022].
U.S Geological Survey, n.d. İzmit earthquake of 1999.
[image] Available at: <https://www.britannica.com/event/Izmit-earthquake-of-1999>
[Accessed 12 September 2022].