September 19, 2022 - South Australia

South Australia

Outside of Antarctica, Australia is the driest continent on Earth—and South Australia is Australia’s driest state. Roughly twenty percent of the state receives more than 10 inches (250 mm) in a year and less than ten percent receives more than 16 inches (400 mm). The aridity is so extreme, it becomes obvious even in satellite images, with the dry, dusty, red-soiled interior giving way to a fringe of green vegetation near the coast, where rain is relatively abundant.

On September 15, 2022, the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Terra satellite acquired a true-color image of a sunny day in South Australia.

The dominant colors in this image are tans and ochre tones, testimony to a dry region with sparse vegetation. Bright, almost startling, white and gray swaths and patches mark ephemeral lakes, which remain dry and encrusted with salt and other minerals most of the time, but can fill with water when the rare abundant rain falls. The large salt-encrusted lakes, from west to east, are Lake Gairdner, Island Lagoon, and Lake Torrens, and Lake Frome.

Lying between Lake Torrens and Lake Frome, the large patch of green, brown, and black marks the Flinders Ranges, the largest mountain system in Australia. It’s a classic example of a “folded mountain range”—a type of mountain formed when tectonic plates collide, folding and pushing layers of land into mountain ranges. Although the Flinders Ranges is semi-arid at best, vegetation such as cypress pine and black oak have adapted to the environment and grow abundantly in some parts of the mountains.

The truly lush vegetation sits in the south, near the coastline, where annual rainfall is relatively abundant. Most of the population of South Australia live in the green belt of the state near the blue waters of the Great Australian Bight. This area is also the heartland of South Australian agriculture, where most of the crops such as wheat and barley are grown and livestock such as swine and poultry are concentrated. Some crops are grown inland, but usually depend on irrigation. Some livestock, such as cattle, also are raised in the interior.

The wedge of blue at the far south of this image is Spencer Gulf, an indentation off the Great Australian Bight. One of its claims to fame is that each winter it attracts the worlds largest congregation of Australian giant cuttlefish. These curious creatures, which can grow over 3 feet (1 meter) long, cluster in Spencer Gulf each winter to spawn.

Image Facts
Satellite: Terra
Date Acquired: 9/15/2022
Resolutions: 1km (213.8 KB), 500m (525.7 KB), 250m (297.3 KB)
Bands Used: 1,4,3
Image Credit: MODIS Land Rapid Response Team, NASA GSFC