Ancient and Modern Earthquake Lights in Northwestern Turkey

Abstract

Before dawn on 17 August 1999 one of the greatest earthquakes in modern Turkish history occurred on the historically active North Anatolian Fault (Ambraseys, 2002). The epicenter lay near the town of Izmit in Kocaeli province, not far east of Istanbul (ancient Constantinople). At Golcuk on the eastern shore of the Sea of Marmara, an eyewitness reported that “the earth came alive with shaking, the sky turned red, a sword of light flew out of the sea” (Gore, 2000). Rothaus et al. (2003) interviewed many other Golcuk eyewitnesses, who independently confirmed that “the sky glowed red” and “the sea glowed red” during the shaking. Since the night was overcast, the investigators could not determine whether the sky glow was atmospheric in origin or was merely cloud-reflected light emitted by a glowing sea. In addition, circular and irregularly shaped lights of white, yellow, red, and blue were videotaped for several minutes near the earthquake epicenter on 25 July, as well as farther to the west, near where the fault line ends, on 16 August (Erkmen, 2001). Barka's (1999) report of “a ball of flame and the sound of an explosion” at the time of the earthquake was later explained as being due to sea mine explosions and to oil refinery fires, although the peculiar “balloons of strong light coming out of the sea” for several days afterward are still under investigation (E. Erkmen, personal communication, 2003). The various lights were widely reported throughout the Turkish media. The sky coloration and the anomalous lights recall a long attested, but poorly understood, epiphenomenon of large earthquakes called “earthquake lights” (Derr, 1973, 1986). Although there are many suggested causes of earthquake lights, the phenomenon in the Izmit instance might conceivably be attributed to an explosion of ground-sequestered methane (marsh gas) (Barka, 1999) or …