Envisat captures South Korea's crude oil leak (Forwarded)

ESA News
http://www.esa.int

11 December 2007

Envisat captures South Korea's crude oil leak

Crude oil from the wrecked 146 000-ton tanker, Hebei Spirit, is seen
polluting the sea off South Korea in this Envisat image.

More than 10 000 tons of oil from the tanker is reported to have leaked into
the sea since colliding with another vessel on Friday 7 December. The South
Korean government has declared the coastal regions, located southwest of
Seoul, where oil is washing onto their beaches disaster areas.

This image was acquired today at 01:40 UTC by the Advanced Synthetic
Aperture Radar (ASAR) aboard ESA's Envisat, while operating in its
wide-swath mode covering an area approximately 400 km by 400 km.

The presence of oil on the sea surface damps down smaller wind generated
waves. It is these waves that reflect the radar signal back in the direction
of the source. When they are damped, the reflected power measured by the
radar is reduced, causing oil slicks to be seen as dark areas on an
otherwise brighter sea.

ASAR, like other space-based radar systems, essentially provide its own
source of illumination and operates at longer wavelengths than optical
sensors. This enables it to observe the Earth's surface at night and through
thick cloud cover.

[NOTE: An image supporting this release is available at
http://www.esa.int/esaCP/SEM1CF361AF_index_1.html ]