December 27, 2010 - New Zealand

New Zealand

On December 4, 2010, the clouds parted over the southern Pacific Ocean, revealing a striking tableau of springtime colors on and around on South Island, New Zealand. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this true-color image the same day.

The navy blue ocean waters off the east coast are filled with coils and swirls of teal, turquoise and greens, evidence of a large springtime phytoplankton bloom. The bloom is over the Chatham Rise, a shallow sea which is home to New Zealand’s most important and productive fishing grounds. The swirling colors are created by the chlorophyll and other pigments used by phytoplankton for the process of photosynthesis.

On South Island, bright white snow capping the Southern Alps forms a sharp contrast to the brilliant turquoise of Lake Pukaki, the largest of three parallel alpine lakes on the eastern slope of the mountain range (the other two are Lakes Tekapo and Ohau). The lake’s color is caused by light reflected from fine silt and sediment – primarily quartz and albite – suspended in the turbid waters. Much of the lake’s water originates from the glaciers that surround Aoraki/Mount Cook - the Tasman Glacier to the east and the Hooker Glacier (west). In this image, Aoraki/Mount Cook lies to the northeast of the lake. The glacial valleys are marked by a snow-free “Y” shape. The glaciers themselves appear bright white or light gray, and can be seen at the highest resolution of the image.

The Tasman Glacier has been retreating rapidly since 1977, when monitoring began, leading to concern that it may disappear completely. In November, 2010, the National Institute of Water and Atmospheric Research (NIWA) reported that there was a slight, but relatively insignificant net gain in the amount of snow at the top of the key of the South Island glaciers in the past one year period. While this small gain helped to hold some glaciers in a steady state temporarily, the report states that the overall trend in the last 33 years continues downward.

Image Facts
Satellite: Aqua
Date Acquired: 12/4/2010
Resolutions: 1km ( B), 500m ( B), 250m ( B)
Bands Used: 1,4,3
Image Credit: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC