Geoscience Reference
In-Depth Information
Chapter 9
INTRODUCTION
A devastating earthquake with a magnitude of Mw 7.4 occurred on the North Anatolian
Fault Zone (NAFZ) of Turkey on August 17, 1999 at 00:01:39 UTC (3:01 am local
time). The aim of this study is to propose a new approach to automatically identify
earthquake induced damage areas which can provide valuable information to sup-
port emergency response and recovery assessment procedures. This research was con-
ducted in the Adapazari inner city, covering a 3 × 3 km area, where 11,373 buildings
collapsed as a result of the earthquake. The Satellite Pour l'Observation de la Terre
(SPOT) high resolution visible infrared (HRVIR) Pan images obtained before (June
25, 1999) and after (October 4, 1999) the earthquake were used in the study. Five steps
were employed to conduct the research and these are: (i) geometric and radiometric
correction of satellite images, (ii) Fast Fourier Transform (FFT) of pre- and post-
earthquake images and filtering the images in frequency domain, (iii) generating dif-
ference image using Inverse Fast Fourier Transform (IFFT) pre- and post-earthquake
images, (iv) application of level slicing to difference image to identify the earthquake
induced damages, (v) accuracy assessment of the method using ground truth obtained
from a 1/5,000 scale damage map. The total accuracy obtained in the research is
80.19%, illustrating that the proposed method can be successfully used to automati-
cally identify earthquake-induced damage areas.
Turkey is one of the most seismically active regions on the earth. Different fault
systems in Anatolia and the surrounding regions were created due to the complex plate
interactions among Arabia, Eurasia, and Africa (Tan et al., 2008). The NAFZ and the
East Anatolian Fault Zone (EAFS) are the main strike-slip fault belts in Turkey where
several earthquakes have occurred, resulting in huge numbers of fatalities over the past
several hundred years (Table 1).
Table 1.
Historical earthquakes in Turkey (USGS, 2008).
Date
Location
Magnitude (Mw)
Fatalities
August 17, 1668
Anato1ia
8.0
8,000
August 9, 1912
Murefte (Ottomon Empire)
7.8
2,800
October 3, 1914
Burdur (Ottoman Empire)
7.0
4,000
December 26, 1939
Erzincan
7.8
32,700
November 26, 1943
Ladik, Samsun
7.6
4,000
March 18, 1953
Gonen
7.3
1,073
August 19, 1966
Varto, Mus
6.8
2,529
March 28, 1970
Gediz
6.9
1,086
October 30, 1983
Erzurum
6.9
1,342
August 17, 1999
Izmit
7.2
11,718
