NASA MODIS Image of the Day: December 20, 2011 – Kamchatka Peninsula, eastern Russia
The Kamchatka Peninsula in eastern Russia appeared as a frozen portrait painted in light and shadow on a winter afternoon in mid-December, 2011.
The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Aqua satellite captured this true-color image on December 19, 2011 at 02:15 UTC (2:15 p.
m. local time). On this day, the sun rose in Petropavlovsk-Kamchatsky, home to nearly half the population of the peninsula, at about 9:44 a.m. and set about 4:48 p.m. At this time of the year, the sun stays low in the sky, rising only about 11° off the horizon at its peak. At 2:15 p.m., the solar elevation was just below peak, at about 10°. This low angle allowed sunlight to reflect brightly off the snow back to the MODIS instrument, but also created long, pronounced shadows to the northeast of mountain peaks. In this image, long triangular shadows are cast by several volcanoes, including Shiveluch in the north, (10,771 feet above sea level), Klyuchevskaya (15,863 feet) found in a grouping of peaks in the center, and Kizimen just to the southeast (7,795 feet). At this solar elevation, heights of the mountains can be roughly estimated by the length of the shadows they cast. Roughly speaking, each 1,000 foot of elevation above the surrounding land results in a shadow of about 5,000 feet extending from the mountain base. Only six days before this image was captured, Kizimen was emitting heavy clouds of volcanic ash to the southeast, covering the snow with a dark gray mantle. In this image, some snow in the valleys near the more active volcanoes retains a gray coloration, but most of the calderas and the snow southeast of Kizimen appear bright white. This indicates that fresh snow has fallen since the last ash eruptions.
