Seaside Wave and Shadow
January 16, 2010
Photographer: Konstantinos Christodoulopoulos; Kostas's Web site
Summary Author: Konstantinos Christodoulopoulos; Jim Foster
The photo above showing a curious wave approximately three feet (one meter) high in the Saronic Gulf near the seaside village of Almiri, Greece was captured on December 31, 2009. Though this area is prone to earthquakes the wave featured here is likely not seismic in nature. As can be seen in the center of the photo the wave is in the nascent stage of breaking. Waves break as their forward speed is abruptly slowed when approaching shore. In essence, friction from the beach slows the lower portion of the wave allowing the top or wave crest to overshoot the base. This occurs when the water depth is about is 1/7 of the wavelength.
Also of interest is the shadow on the steep forward side of the wave -- the wave is moving toward the camera. It's comparable in color to the shadow mentioned in yesterday’s Earth Science Picture of the Day. In this case, the blue tinged shadow is attributable to both reflections from the sea as well as from the sky.
Technical details: Canon EOS 450D camera; Canon EF 200 mm lens; f/5.6; 1/640 second; ISO 100.
Almiri coordinates: 37.846936, 23.006614