File:New Zealand (MODIS 2020-03-09).jpg

English: On March 5, 2020, the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Aqua satellite acquired a true-color image of the southwestern section of New Zealand’s gorgeous South Island on a sunny summer day.

The rugged, steep Southern Alps runs the length of South Island. These mountains were created as the Pacific Plate, the section of the Earth’s crust that holds the Pacific Ocean, including parts of New Zealand’s South Island, sinks beneath the Australian Plate, which holds the rest of New Zealand. That process continues today, as the slow collision between the two plates pushes the mountains upwards and fosters volcanic activity on the country’s North Island. Not only do the mountains mark the line between two tectonic plates, they also create different climate regions.

The shoreline northwest of the mountains receives more rain than any other place in the South Island. In this image, clouds cover the shoreline, likely bringing rain to the temperate rain forest. To the south, the shore turns dark brown where rocky mountain terrain extends to the Pacific Ocean. Fingers of water cut into the western shore where glaciers cut deep fjords over time.

The landscape on the east side of the mountains is dramatically different. The rain shadow of the Southern Alps receives relatively little rain and therefore appears tan instead of green. The dry landscape is punctuated by alpine glacier lakes that hang like sapphire and aquamarine pendants amid the high peaks of the Southern Alps.