This image shows Death Valley, California, centered at 36. One question concerns how alluvial fans are formed and change through time under the influence of climatic changes and earthquakes.
Alluvial fans are gravel deposits that wash down from the mountains over time.
They are visible in the image as circular, fan-shaped bright areas extending into the darker valley floor from the mountains. Information about the alluvial fans helps scientists study Earth's ancient climate. Such information can be used to study the occurrence and movement of dust storms and sand dunes. The goal of these studies is to gain a better understanding of the record of past climatic changes and the effects of those changes on a sensitive environment. This may lead to a better ability to predict future response of the land to different potential global climate-change scenarios.